How to accurately measure heart rate and recognize when it's dangerous

Every day, an adult heart beats about 100,000 times and pumps over 7,000 liters of blood throughout the body. However, not everyone knows how to measure heart rate correctly or understands their normal heart rate. Many people only discover abnormalities when symptoms such as palpitations, dizziness, shortness of breath, or chest pain appear, which can lead to delayed treatment.

Understanding how to measure heart rate at home, knowing your normal heart rate by age, and recognizing what heart rate is dangerous will help you monitor your cardiovascular health more proactively, especially if you exercise regularly, have cardiovascular disease, or are at high risk for blood pressure issues. In this article, Tiptory will guide you through simple and easy heart rate measurement methods, and explain how to interpret the results and when to seek medical attention to effectively protect your heart.

Part 1: The most accurate way to manually measure heart rate

Step 1: How to manually determine your heart rate

Position correctly to measure heart rate

• Start by turning your palm upward to easily locate the pulse.
• Place the tips of your index and middle fingers of your other hand on the inside of your wrist, just below the base of your thumb, in the area between the bone and the tendon. This is a commonly used position for heart rate measurement at home because the pulse is quite clear.
• If you have difficulty feeling the pulse in your wrist, move your two fingers to the side of your neck, gently placing them in the groove next to the windpipe. This is also a common location to check your pulse and heart rate.

Do not use your thumb to feel for the pulse

• Avoid using your thumb when checking your normal heart rate because your thumb also has its own pulse.
• If you use your thumb, you might confuse your thumb's pulse with the pulse of the person being measured, leading to an inaccurate heart rate measurement result.

Adjust pressure appropriately

• For most people, a light touch with two fingertips is enough to feel the pulse.
• If you don't feel a pulse, gradually increase the pressure or move your fingertips a few millimeters until you feel a regular beat.
• Do not press too hard, especially when measuring in the neck area, as it can reduce pulse sensation or cause discomfort.

Check pulse before starting to count

• Once you've found the pulse location, feel a few consecutive beats to ensure the pulse is clear and stable before proceeding to count.
• This is an important step to ensure a precise heart rate measurement, allowing you to assess your normal heart rate or identify early if a heart rate is dangerous, to facilitate timely monitoring or medical examination.

Step 2: Count heart rate and interpret results

Count heart beats for 30 seconds

• After locating the pulse, start counting the number of heartbeats for 30 seconds.
• You can use a stopwatch or a timer on your phone to accurately track the time.
• When 30 seconds are up, multiply the counted beats by 2 to calculate your heart rate per minute (BPM). This is a common method for heart rate measurement at home.

Ensure accurate measurement results

• While counting, keep your body relaxed, do not talk or move excessively to avoid affecting the results.
• If you get distracted or are unsure about the number of beats counted, repeat the process from the beginning for more reliable results.
• To monitor normal heart rate, it is recommended to measure at the same time each day, especially when the body is at rest.

Note if heart rate is irregular

• Occasionally, a heart may skip a beat or beat earlier than usual, and this is not always a dangerous sign.
• However, if you notice your heart rate is consistently irregular throughout the 30 seconds, especially if your heart is beating very fast or you are over 65, this could be a sign of atrial fibrillation – a type of arrhythmia that requires a doctor's evaluation.

When should you see a doctor?

• If the measurement results consistently show an abnormal heart rate, accompanied by symptoms such as prolonged palpitations, dizziness, shortness of breath, chest pain, or fainting, you should visit a medical facility for examination.
• Regular monitoring will help you understand your normal heart rate and identify early what heart rate is dangerous, enabling timely intervention and treatment.

Step 3: Calculate heart rate per minute

Multiply the result by 2 to calculate heart rate

• After completing the count of heartbeats in 30 seconds, multiply the result by 2 to calculate your heart rate per minute (BPM - Beats Per Minute).
• This is the standard unit used to assess normal heart rate and monitor cardiovascular health.
• For example: If you count 50 beats in 30 seconds, multiply 50 × 2 = 100. Thus, your heart rate is 100 beats/minute.

Measure multiple times for increased accuracy

• For more reliable heart rate measurement results, perform the measurement 2–3 times under the same conditions, such as when at rest.
• Each measurement should be separated by a few minutes to allow the heart rate to stabilize, and avoid measuring immediately after exercise, drinking coffee, or stress.

Calculate the average value of the measurements

• After obtaining 3 results, sum all values and divide by 3 to calculate the average heart rate.
• For example:
  • Measurement 1: 72 beats/minute.
  • Measurement 2: 74 beats/minute.
  • Measurement 3: 70 beats/minute.
  • Average heart rate = (72 + 74 + 70) ÷ 3 = 72 beats/minute.
• This calculation helps reduce errors due to temporary body changes and more accurately reflects your normal heart rate.

Compare with normal heart rate ranges

• After obtaining the final result, compare it with the normal heart rate by age and your health status.
• If your heart rate is consistently too high, too low, or shows prolonged abnormalities, especially when accompanied by palpitations, dizziness, or shortness of breath, you should see a doctor to determine the cause and understand what heart rate is dangerous in your specific case.

Part 2: Is measuring heart rate with a phone accurate?

Phone apps are for reference only

• There are many apps available today that support heart rate measurement with a phone, but the results are often only estimates and cannot replace medical measurement methods.
• Some apps can be off by more than 20 beats/minute, so they should not be used to accurately assess normal heart rate or detect cardiovascular abnormalities.

Suitable for tracking heart rate trends

• You can use an app for a quick check to see if your heart rate increases after walking, jogging, or light to moderate intensity exercise.
• This is a convenient way to monitor changes in heart rate during exercise, but should not be considered a diagnostic result.

Do not rely on it when high accuracy is needed

• If you are exercising at high intensity, have a history of cardiovascular disease, or need to monitor your health as directed by a doctor, you should not rely solely on phone apps.
• In these cases, prioritize manual heart rate measurement, using a specialized heart rate monitor, or certified medical devices for more reliable results.

Apps using the camera are often more accurate

• Apps that require placing a fingertip over the phone's camera and flash (contact apps) typically provide better results than apps that only use the front camera to scan the face (non-contact apps).
• However, both types of apps can still be affected by light, movement, skin temperature, and camera quality, so they cannot replace accurate heart rate measurement methods when you need to know what heart rate is dangerous or monitor cardiovascular conditions.

Part 3: Are smartwatches accurate for measuring heart rate?

Smartwatches work well at rest

• Wearable devices like Fitbits or smartwatches that measure heart rate can track heart rate quite accurately when the body is at rest or engaging in light activity.
• These are useful tools for tracking daily normal heart rate trends, supporting health management and exercise.

Accuracy decreases during vigorous exercise

• When the heart rate exceeds approximately 100 beats/minute, optical sensors on the wrist may start to show inaccuracies.
• If the heart rate increases above approximately 130 beats/minute, especially during high-intensity workouts, the measurement results can become significantly less accurate.
• Therefore, if you feel you have over-exercised but the data on your watch does not match your actual perception, stop and use the manual heart rate measurement method to recheck.

Do not rely entirely on wearable devices

• Smartwatches are very convenient for tracking heart rate during exercise, but they are not medical diagnostic devices.
• If you have cardiovascular disease, are being treated for an arrhythmia, or need precise monitoring as directed by a doctor, it is advisable to use specialized medical devices for more reliable results.

Some factors can skew results

• Wrist sensors may be less accurate on darker skin tones or if there are large tattoos or birthmarks at the wearing site.
• Additionally, wearing the watch too loosely, continuous wrist movement, cold skin, or excessive sweating can also affect measurement quality.
• If the device frequently shows abnormal results or results that do not match actual symptoms, recheck by manual heart rate measurement or a medical device to assess a normal heart rate and determine what heart rate is dangerous in each case.

Part 4: Should you buy a chest strap heart rate monitor?

Note 1: Choose the right heart rate monitor

Choose a device according to your needs

• Not all heart rate monitors have the same accuracy. Before purchasing, clearly define your purpose of use, such as daily health monitoring, exercise support, or cardiovascular disease management.
• Researching reviews from experts or reputable organizations will help you choose a suitable device and avoid wasted costs.

Chest straps provide the most accurate results

• Chest strap heart rate monitors generally provide more accurate results than wrist-worn sensors.
• This is the preferred choice for many athletes and individuals who need close heart rate monitoring during training.
• For people with cardiovascular disease or those who need monitoring as prescribed by a doctor, chest straps are often the preferred device due to their high reliability.
• However, some older models may be affected when operating near devices that emit electromagnetic interference.

Wristwatches are suitable for daily monitoring

• Smartwatches and fitness trackers are very convenient for monitoring normal heart rate, activity levels, and training progress.
• However, wrist sensors can lose accuracy during high-intensity workouts or on dark skin, tattooed areas, or birthmarks.
• This device is suitable for people who want to monitor heart rate trends and maintain motivation to exercise, but it should not be used as a substitute for medical devices when accurate data is needed.

Don't rely too much on exercise machine sensors

• Many treadmills, exercise bikes, or fitness machines have integrated heart rate sensors on the handles.
• This type of sensor often has low accuracy because it is easily affected by grip force, posture, sweat, and the user's movement.
• If you want to know your exact normal heart rate during exercise or assess what heart rate is dangerous, combine manual heart rate measurement or use a more reliable specialized measuring device.

Note 2: Choosing a medical heart monitor

Use medical devices when arrhythmia is suspected

• If you frequently experience symptoms such as rapid heartbeat, irregular heartbeat, palpitations, dizziness, or fainting, you should visit a medical facility for evaluation by a doctor.
• In many cases, the doctor will prescribe a wearable electrocardiogram (ECG) monitor to record the electrical activity of the heart during daily activities.
• This method is much more accurate than manual heart rate measurement or common wearable devices, helping to detect abnormalities that short-term heart rate measurements might miss.

Holter ECG suitable when symptoms occur frequently

• A Holter ECG machine is a compact ECG device worn continuously for about 24–48 hours.
• The device will automatically record heart activity throughout the wearing period, even when you are sleeping, working, or exercising.
• Doctors often prescribe Holter ECG when heart-related symptoms occur quite frequently but not at the exact time of the examination.

Event recorder suitable when symptoms occur occasionally

• If episodes of heart arrhythmia only occur a few times a week or even a few times a month, the doctor may prescribe an Event Monitor.
• This device can be worn for several weeks to increase the chance of recording abnormalities.
• When you feel an abnormal heartbeat or experience symptoms, you just need to press a button on the device to save the electrocardiogram at that moment, helping the doctor easily identify the cause.

When is intensive monitoring needed?

• If your heart rate is consistently abnormal, accompanied by chest pain, shortness of breath, fainting, or if home heart rate measurements show many abnormal signs, you should not self-diagnose.
• Using an ECG device as prescribed by a doctor will help accurately assess a normal heart rate, detect arrhythmias, and determine what heart rate is dangerous to guide appropriate treatment.

Part 5: Home medical devices for heart rate monitoring

Type 1: Blood pressure measurement for heart rate monitoring

Blood pressure measurement helps check heart rate

• Each time blood pressure is measured with an electronic device or at a medical facility, the device often displays the heart rate (Pulse) in addition to the blood pressure reading.
• This is a convenient way to simultaneously monitor blood pressure and heart rate, especially for people with cardiovascular disease, hypertension, or the elderly.
• However, the heart rate displayed on a blood pressure monitor does not replace an electrocardiogram (ECG) if an arrhythmia needs to be diagnosed.

Choosing the right measurement location

• You can check your blood pressure and heart rate at a hospital, clinic, health station, or some community health screening points.
• If you want to actively monitor at home, use a standard blood pressure monitor and read the user manual carefully to ensure accurate results.

Checking the accuracy of home blood pressure monitors

• If your doctor asks you to regularly monitor your heart rate measurement and blood pressure at home, bring your device to your routine check-up.
• The doctor or medical staff can compare the results from your personal device with the specialized equipment at the clinic to assess its accuracy.
• Calibration or regular checks help minimize errors, especially when you need to monitor your health over a long period.

Monitor readings regularly to detect abnormalities

• Measure at the same time each day, after resting for at least 5 minutes, and record the results for easy tracking.
• Long-term monitoring of normal heart rate and blood pressure will help detect abnormal changes early and assist doctors in assessing what heart rate is dangerous and determining appropriate treatment if needed.

Type 2: Electrocardiogram for heart examination

Perform an electrocardiogram if heart abnormalities are suspected

• If your heart rate is consistently too fast, too slow, or you experience symptoms such as chest pain, shortness of breath, palpitations, dizziness, or fainting, your doctor may order an electrocardiogram (ECG).
• This is a simple, safe, and painless test that records the electrical activity of the heart to detect various issues such as arrhythmias, myocardial ischemia, or other abnormalities.

The electrocardiogram procedure is quick

• When performing an ECG, medical staff will attach electrodes to the chest, arms, and legs to collect electrical signals from the heart.
• The electrocardiogram recording process usually takes only a few minutes and does not require invasive intervention.
• The results will help the doctor assess more accurately than manual heart rate measurement or common wearable devices.

Consider using a wearable ECG device

• If the clinic ECG results are normal but you still frequently experience abnormal symptoms, your doctor may prescribe a wearable ECG device for continuous monitoring over a period of time.
• This device helps record heart activity during daily life, thereby increasing the chance of detecting infrequent arrhythmias.

Stress electrocardiogram assesses heart function

• In some cases, your doctor may request a stress electrocardiogram, which involves monitoring an ECG while you walk or run on a treadmill at gradually increasing intensity.
• This test helps assess the heart's response to exercise, detect abnormalities that only appear during exertion, and determine safe exercise levels.

Combine results to monitor cardiovascular health

• Although monitoring normal heart rate at home is very helpful, ECG remains an important method for diagnosing cardiovascular diseases.
• If your heart rate measurement results are consistently abnormal or you are unsure what heart rate is dangerous for your health condition, consult your doctor for appropriate monitoring and testing methods.

Type 3: Hospital heart monitors

Heart monitors help detect abnormalities early

• In hospitals, patients are often connected to a cardiac monitor to continuously monitor vital signs, especially when treating cardiovascular disease, post-surgery, or in emergency situations.
• This device helps medical staff quickly detect abnormal changes in heart rate, allowing for timely intervention when dangerous signs appear.

Device displays heart rate in real-time

• The monitoring screen typically displays HR (Heart Rate) or PR (Pulse Rate), showing the heart rate in beats per minute (BPM).
• Unlike manual heart rate measurement which only records at a single point in time, a monitor continuously updates results, helping doctors and nurses closely track the patient's condition.

ECG displayed directly on screen

• In addition to the heart rate reading, the screen also displays the electrocardiogram (ECG) waveform, reflecting the heart's electrical activity in real-time.
• Each heartbeat creates a characteristic wave cycle, helping medical staff quickly identify arrhythmias or other abnormal changes.

Does not replace a doctor's diagnosis

• Heart monitors are tools that help with continuous monitoring, but the results shown always need to be combined with clinical symptoms, medical history, and other tests by a doctor to make an accurate diagnosis.
• If at-home heart rate measurements show abnormal results, or if you are concerned about what heart rate is dangerous, visit a medical facility for examination with specialized equipment instead of relying solely on personal monitoring devices.

Part 6: How to measure resting heart rate most accurately

Measure heart rate when the body is relaxed

• Resting heart rate is the number of times your heart beats per minute when your body is not active and not affected by stress or stimulants.
• This is an important indicator for evaluating normal heart rate, monitoring cardiovascular health, and early detection of certain abnormalities.

Measure heart rate correctly

• Apply the method of measuring heart rate by placing two fingers on your wrist or neck to feel your pulse.
• Count the number of heartbeats in 30 seconds, then multiply the result by 2 to calculate the heart rate per minute (BPM).
• To increase accuracy, you should measure 2-3 times and take the average value.

Ensure your body is at rest before measuring

• Do not measure immediately after exercise, drinking coffee, tea, energy drinks, or after experiencing stress. It is best to wait about 1-2 hours after these factors before checking.
• This condition helps to accurately reflect a normal resting heart rate.

Choose an appropriate posture

• You can measure while sitting or standing, as long as you feel comfortable.
• If you have just changed posture after sitting or lying down for too long, stand or sit steadily for about 20 seconds before starting to measure your heart rate, as heart rate can temporarily change when switching postures.

Maintain a relaxed state of mind when measuring

• Strong emotions such as anxiety, anger, excitement, or fear can cause your heart rate to increase faster than normal.
• Therefore, perform the measurement when your mood is stable to ensure the results accurately reflect your cardiovascular condition.

Track results over time

• Regularly checking your resting heart rate, especially at the same time each day (e.g., after waking up in the morning), will help you easily recognize changes in your normal heart rate.
• If the results are consistently too high, too low, or you experience symptoms such as palpitations, dizziness, shortness of breath, or chest pain, you should see a doctor for an accurate assessment and to determine what heart rate is dangerous for your health condition.

Part 7: Latest standard heart rate chart by age

Step 1: Calculate heart rate for moderate exercise

Determine maximum heart rate by age

• Before setting exercise goals, you need to estimate your maximum heart rate using the formula:
  • 220 - age = Maximum Heart Rate (BPM).
• This is a common formula to determine the safe heart rate limit during physical activity.
• For example: A 55-year-old person will have an estimated maximum heart rate of 220 - 55 = 165 beats/minute.

Calculate target heart rate for moderate intensity exercise

• For moderate-intensity exercises such as brisk walking, light cycling, or relaxed swimming, the appropriate target is about 70% of maximum heart rate.
• The calculation formula is as follows:
  • Target Heart Rate = Maximum Heart Rate × 0.7.
• Example:
  • Maximum heart rate: 165 beats/minute.
  • Target for exercise = 165 × 0.7 ≈ 116 beats/minute.

Understand the appropriate heart rate range during exercise

• Instead of aiming for a fixed number, you can maintain your heart rate within the range of 64%–76% of your maximum heart rate to achieve effective moderate-intensity exercise.
• For a 55-year-old, this range is approximately 106–125 beats/minute.
• Maintaining your heart rate within this zone helps improve cardiovascular endurance, aids in weight management, and enhances physical fitness without putting excessive strain on your heart.

Monitor heart rate during exercise

• During exercise, you can apply the method of measuring heart rate manually or use a smartwatch, chest strap, or specialized monitor to track it.
• If your heart rate exceeds the target for a prolonged period or you experience symptoms such as chest pain, shortness of breath, dizziness, or lightheadedness, reduce the intensity or stop exercising and rest.

Adjust goals according to health status

• The above formula is an estimation and is suitable for most healthy adults.
• Individuals with cardiovascular disease, hypertension, those taking medications that affect heart rate, or the elderly should consult a doctor to determine the appropriate normal heart rate range during exercise.
• Exercising at the correct intensity will help improve exercise effectiveness and reduce the risk of what heart rate is dangerous during physical activity.

Step 2: Calculate heart rate for high-intensity exercise

Determine maximum heart rate before exercise

• To calculate your target heart rate for high-intensity exercise, first estimate your maximum heart rate using the formula:
  • 220 - age = Maximum Heart Rate (BPM).
• This serves as a basis for you to control exercise intensity and train safely.

Calculate target heart rate for strenuous exercise

• For high-intensity exercises, your heart rate should reach approximately 85% of your maximum heart rate.
• The calculation formula is:
  • Target Heart Rate = Maximum Heart Rate × 0.85.
• Example:
  • A 55-year-old person has a maximum heart rate of approximately 165 beats/minute.
  • The target for high-intensity exercise is 165 × 0.85 ≈ 140 beats/minute.

Maintain heart rate within the appropriate training zone

• Instead of following a fixed number, you should maintain your heart rate within the range of 77%–93% of your maximum heart rate.
• For a 55-year-old, the target heart rate range will fluctuate around 127–153 beats/minute.
• This range is suitable for exercises such as running, high-speed swimming, intense cycling, playing soccer, or other endurance sports.

Recognize signs of over-exertion

• When exercising at high intensity, you will breathe faster and find it difficult to speak continuously without pausing for breath.
• However, if you experience chest pain, severe shortness of breath, dizziness, lightheadedness, or a heart rate that is too fast and prolonged, stop exercising immediately and check your heart rate.
• If necessary, use the method of measuring heart rate manually or use a reliable measuring device to assess your current condition.

Adjust intensity according to physical condition

• The target of 85% of maximum heart rate is suitable for individuals who already have a good fitness foundation and are accustomed to exercising.
• Beginners, the elderly, or individuals with cardiovascular disease should prioritize exercising at low to moderate intensity and only gradually increase it under the guidance of a medical professional.
• Regularly monitoring your normal heart rate during exercise will help you achieve better training results, while reducing the risk of exceeding what heart rate is dangerous for your body.

Step 3: When to consult a specialist?

Formulas are for reference only

• Formulas for calculating target heart rate based on age help most healthy individuals determine appropriate exercise intensity.
• However, these are only estimated values and do not fully reflect an individual's health status, physical fitness, or medical history.
• If you want to develop a safe and effective exercise plan, you should combine the method of measuring heart rate with advice from a doctor or qualified trainer.

Individuals with heart conditions or on medication should seek advice

• Consult your doctor before exercising if you have cardiovascular disease, arrhythmia, or are taking medications that may alter your heart rate, such as beta-blockers.
• In these cases, a normal heart rate and target heart rate range may differ from standard calculation formulas.

Certain individuals need to be checked before strenuous exercise

• You should have a health assessment before starting a high-intensity exercise program if you belong to one of the following groups:
  • Men over 45 years old.
  • Women over 55 years old.
  • Individuals with diabetes.
  • Individuals with risk factors for cardiovascular disease such as hypertension, dyslipidemia, smoking, obesity, or a family history of heart disease.
• Pre-exercise screening helps reduce the risk of cardiovascular events and determines appropriate exercise intensity.

Athletes should determine their heart rate zones more precisely

• For professional trainers or athletes, determining the target heart rate needs to be more precise to optimize performance.
• If in-depth assessment is not yet available, one can refer to a calculation method based on Heart Rate Reserve, which is maximum heart rate minus resting heart rate, and then calculate the training zone according to the desired intensity.
• This method is more suitable for individuals with a low resting heart rate due to regular exercise and more accurately reflects cardiovascular capacity.

Monitor health throughout the exercise process

• Regardless of the formula used, you should regularly check your normal heart rate during and after exercise to adjust the intensity accordingly.
• If heart rate measurement shows abnormal readings or if you experience chest pain, shortness of breath, dizziness, fainting, or irregular heartbeat, stop exercising and seek immediate medical attention to determine what heart rate is dangerous and receive guidance on safe exercise based on your health condition.

Part 8: What heart rate is dangerous and requires medical attention?

Note 1: When does heart rate require medical attention?

Understand normal resting heart rate levels

• In most healthy adults, a normal heart rate at rest typically ranges from 60–100 beats/minute.
• If you have correctly performed the heart rate measurement while your body is relaxed and the results are consistently outside this range, you should arrange for a medical examination to assess the cause.

A heart rate below 60 beats/minute is not always dangerous

• A heart rate below 60 beats/minute (bradycardia) can be a normal sign in people who exercise regularly or are in good physical condition.
• Athletes' hearts often pump more blood with each beat, so they don't need to beat as fast to meet the body's demands.
• If you are healthy, exercise regularly, and do not experience symptoms such as dizziness, fainting, unusual fatigue, or shortness of breath, a low heart rate is usually not a cause for concern.

A heart rate above 100 beats/minute needs to be monitored

• If your resting heart rate is consistently above 100 beats/minute, this could be a sign of various conditions such as stress, fever, dehydration, hyperthyroidism, anemia, or cardiovascular diseases.
• You should monitor for accompanying symptoms and visit a medical facility if the condition persists or recurs frequently.

When to seek immediate medical attention?

• Go to a hospital or medical facility if heart rate measurement shows excessively high or low readings accompanied by symptoms such as:
  • Chest pain.
  • Shortness of breath.
  • Dizziness or lightheadedness.
  • Fainting.
  • Irregular heartbeat or prolonged palpitations.
• These symptoms could indicate what heart rate is dangerous for the body and require a doctor's examination with an electrocardiogram (ECG) or specialized tests.

Regular heart rate monitoring to protect cardiovascular health

• Regularly checking your normal heart rate helps you detect early abnormal changes in the cardiovascular system.
• If at-home heart rate measurement results are consistently abnormal for several days, even without clear symptoms, you should proactively seek medical attention for timely advice and treatment.

Note 2: Signs requiring immediate emergency care

Go to the hospital when heart rate changes suddenly

• If your heart rate suddenly becomes much faster or slower than normal and does not stabilize after about 1–2 minutes of rest, you should go to the hospital or call emergency services immediately.
• Do not be subjective or simply continue measuring your heart rate at home, as this could be a sign of arrhythmia or a serious cardiovascular condition.

Do not ignore warning symptoms

• Seek emergency medical attention if a change in heart rate is accompanied by one or more of the following signs:
  • Chest pain or tightness.
  • Shortness of breath.
  • Dizziness or lightheadedness.
  • Fainting or loss of consciousness.
  • Pounding heart, palpitations, or prolonged irregular heartbeat.
• These symptoms could indicate what heart rate is dangerous and need immediate evaluation at a medical facility.

Recognize signs of bradycardia

• Bradycardia can reduce the amount of blood and oxygen supplied to the body's organs.
• Patients may experience symptoms such as:
  • Unusual fatigue.
  • Dizziness.
  • Shortness of breath.
  • Fainting or feeling faint.
• If these symptoms appear along with a low heart rate, a doctor should be consulted as soon as possible.

Recognize signs of tachycardia

• Tachycardia makes the heart work harder than normal and can increase the risk of complications if prolonged.
• Common symptoms include:
  • Palpitations or a racing heart.
  • Shortness of breath.
  • Dizziness.
  • Chest pain.
  • Fainting or loss of consciousness.
• These are all signs that should not be self-monitored at home but require urgent medical attention.

Prioritize safety when severe symptoms appear

• Knowing how to measure heart rate and monitoring your normal heart rate helps you detect abnormalities early, but it cannot replace a doctor's diagnosis.
• If heart rate measurement shows abnormal readings accompanied by the symptoms mentioned above, go to a medical facility immediately for an electrocardiogram (ECG) and necessary tests to determine the cause and provide timely treatment.

Notes on measuring heart rate

New formula can be applied to estimate maximum heart rate

• In addition to the popular formula 220 - age, some studies show that the following formula may estimate maximum heart rate more accurately, especially in middle-aged and older adults:
  • 208 - (0.7 × age).
• For example: A 60-year-old person would have an estimated maximum heart rate of:
  • 208 - (0.7 × 60) = 166 beats/minute.
• However, this is still only a reference formula. Normal heart rate and target heart rate zones can vary depending on an individual's health status, exercise level, and medical conditions.

Do not use your thumb to take your pulse

• When performing heart rate measurement, use your index and middle fingers to feel the pulse at your wrist or neck.
• Do not use your thumb because the thumb itself has an artery with a rather distinct pulse.
• Using your thumb can cause you to confuse your own pulse with that of the person being measured, leading to inaccurate heart rate measurement results.

Perform the correct technique for reliable results

• Place your fingertips lightly on the pulse point, avoiding pressing too hard as this can make it difficult to feel the pulse.
• Count your heart rate when your body is relaxed and take multiple measurements if needed to reduce errors.
• Applying the correct heart rate measurement method will help you more accurately assess your normal heart rate and early recognize what heart rate is dangerous, thereby proactively taking care of your cardiovascular health.

References

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Content edited by: Ashley Wright Nguyen.

Information consulted and verified by expert: Emily Johnson.