Normal vs. Dangerous Heart Rate: What Does It Mean
Every time your heart contracts, it pumps deoxygenated blood over to your lungs to pick up oxygen, then sends that freshly oxygenated blood out through the aorta to the rest of your body. That’s how your organs get the oxygen they need. If your resting heart rate is on the lower side, that’s actually a good sign—it means your heart’s working efficiently. On the flip side, if your heart’s beating too quickly, it doesn’t have enough time to fill up between beats, so it can’t pump blood as well as it should.
Athletes usually have lower heart rates because they train their hearts through regular exercise. Their bodies get stronger, and their hearts pump blood more effectively. If you’re curious about your own heartbeat, you can check your pulse on your wrist. Just press your index finger and middle finger on the inside of your wrist, right along the radial artery, and count the beats for 15 seconds. Multiply that number by four, and you’ve got your beats per minute.
Sometimes, heart rates wander outside the normal range. When your heart races too fast, that’s called tachycardia. When it’s too slow, that’s bradycardia. These don’t usually just happen out of nowhere—there’s often something else going on behind the scenes.
Heart rate also changes with age. Kids have faster heartbeats than adults. For most healthy adults, a normal resting heart rate sits right around 72 beats per minute.
What is Considered a Dangerous Heart Rate?
A dangerous heart rate can differ according to a person's individual characteristics (age, total health, and level of fitness). A sustained heart rate that is not in the average range for a person's age level and their activity level may mean that there is a problem with that person's health.
For an adult at rest, generally, a person with a heart rate of more than 100 beats per minute can be considered to have an elevated (tachycardia) heart rate, and a person having a heart rate less than 60 beats per minute can be considered to have a low (bradycardia) heart rate. But there are many things that could affect the heart rate, including stress, anxiety, physical activity and/or certain medications.
Some people may have a consistently elevated (or abnormal) heart rate and may have a heart condition or arrhythmia such as atrial fibrillation, ventricular tachycardia or other types of arrhythmias. These disorders can pose an increased risk of complications, including stroke, heart failure, and sudden cardiac arrest.
What are the Normal Heart Rate Ranges?
Heart rates for normal functioning can depend upon many different variables, including age, activity level, and general health. Generally speaking, a resting heart rate (RHR) for an adult should be somewhere between 60 beats per minute (bpm) and 100 bpm. An exception to this is with athletes or people who participate in high levels of exercise; those individuals usually have resting heart rates under 60 bpm, but that too would be considered a normal resting heart rate for them.
Maximum heart rate (MHR): MHR is defined as the highest number of heartbeats that can be reached during intense cardiovascular activity. MHR can also be estimated by using the formula (220 minus age). For example, if a 30-year-old is performing intense exercise, then they should expect to achieve an MHR of approximately 190 bpm (220 - 30). However, it should be noted that individual differences apply and therefore this is merely an approximation.
Target heart rate zone: When someone exercises, it is usually recommended that they stay within their target heart rate zone. The target heart rate zone is usually defined as a percent of the MHR, and therefore will vary depending on whether the individual is performing moderate or vigorous cardiovascular activity. Typically, on average, the following is true: for moderate cardiovascular exercise (50% to 70% of the MHR) & for vigorous cardiovascular exercise (70% to 85% of the MHR).
What Factors Can Affect the Heart Rate?
Heart rate varies depending on a number of different factors, including:
Physical activity: Working out and doing physical activities causes you to have a higher heart rate because of the size of the muscles using the most oxygen. As a result, your heart must work harder in order for your whole body to be able to get that oxygen.
Stress: Emotional stress will stimulate the body by releasing adrenaline into the body, resulting in a higher heart rate due to these factors. The amount of adrenaline released will determine how elevated your heart rate is compared to where it would be without any type of emotional stress.
Temperature: Your heart rate can also change as a result of either hot or cold temperatures. A warmer body will result in an increased heart rate in order to help dissipate heat due to excessive sweating and regulate body temperature by using the blood. Cold weather will result in your body increasing the heart rate in order for you to conserve heat throughout the body as well as ensure your vital organs have adequate blood flow.
Medication: There are medications (beta-blockers, stimulants, cough/cold medicines, asthmatic medications, etc.) that can influence the heart in both increased and decreased heart rate.
Alcohol: The temporary effect of alcohol consumption on heart rate is that it dilates blood vessels and increases blood flow.
Caffeine and stimulants: Caffeine and other stimulants that are present in coffee, tea, energy drinks, and certain drugs may increase the heart rate through the stimulation of the nervous system.
Nicotine: Smoking and nicotine-based products have the potential to elevate the heart rate and blood pressure as they stimulate the secretion of adrenaline and narrow the blood vessels.
Age: The resting heart rate is also likely to decline with age because of the alteration of the heart rate and fitness level.
Fitness level: If an individual exercises regularly and is physically fit, then the resting heart rate can decrease because the heart becomes more effective at delivering blood.
Medical conditions: There are medical conditions that can influence heart rate, and they are heart disease, thyroid diseases, electrolyte abnormalities, and disorders of the autonomic nervous system.
Hormonal variations: Hormonal variations due to menstruation, pregnancy, menopause, etc., might affect heart rate.
Hydration and blood volume: Dehydration and the variation of blood volume may induce some changes in the heart rate, as it changes the capacity of the body to continue with proper blood flow and circulation.
How to Measure Your Heart Rate?
Heart rate can be measured in a number of ways, both manually and by using heart rate devices. Here are some common ways:
Manual pulse check: To check your pulse manually, you can put your index and middle finger on the radial artery, which is on the upper side of the thumb or your carotid artery, which is on the side of your neck just below your jaw line. Divide your heart rate by 4 by counting the beats that you feel in 15 seconds.
Wearable heart rate monitors: The wearable products made include fitness watches, smart watches, and chest straps that have sensors capable of monitoring your heart rate all day long. Most of these gadgets also give real-time data on the heart rate during exercise and other activities.
Smartphone applications: It exists that a number of smartphone applications can be used that utilise the camera and flash of the phone to monitor changes in blood flow and determine heart rate. The apps normally make you put the tip of your finger over your camera lens as it measures your pulse.
Blood pressure monitor: There are also automatic blood pressure monitors that have a heart rate monitor built in. All you need to do is measure your blood pressure as per the instructions, and the machine will show you your heart rate and your blood pressure levels.
ECG/EKG devices ECG devices (also known as EKG) are medical-grade devices that measure the heart's electrical activity. These machines are mostly applicable in clinical institutions but can also be used at home. They are very precise in the measurement of the heart rate and can identify changes in heart rhythm.
Pulse oximeter: The pulse oximeter is a small gadget that is clapped to the tip of your finger and monitors the oxygen level in your blood and also the rate of your heartbeat. It employs light sensors in order to identify alterations in blood volume and determine heart rate.
Tachycardia
Tachycardia is a disease whereby the normal Heart rate remains elevated, more than 100 beats per minute, over an extended duration. This can be accompanied by fatigue, dizziness and fainting-like symptoms. Tachycardia can be of the following types.
Multifocal Atrial and moderate to severe lung disease.
This kind of Tachycardia is experienced when the patient is in chronic pulmonary obstructive disease of the lungs.
Pneumonia occurs when the lungs are severely involved and then oxygenation proves to be a complication.
CHF is a failure of the heart to pump sufficient amounts of blood.
Pulmonary embolism happens due to blockage of the major artery of the lung.
Lung cancer
Lung failure
Ventricular or Venus Tachycardia is linked with such diseases as cardiomyopathy and coronary artery disease (CAD). In this instance, the heart rate increases to levels more than 100 beats per minute and this may result into loss of consciousness, dizziness and collapse.
The occurrence of the SA node abnormalities is associated with Sinu Tachycardia. The heart is conducted to by the electrical impulses of the SA node, the contraction and relaxation of the heart muscles ensue. Loss of proper functioning of the SA node causes abnormal rhythms and irregular beating by the heart, giving rise to sinus tachycardia.
Bradycardia
Long-term bradycardia, or having a resting heart rate of fewer than 60 beats per minute over time, can lead to very serious issues if it's not treated. Bradycardia will usually happen for a number of reasons, including the use of prolonged beta blockers, sleep apnea, heart disease, age, and electrolyte imbalances. If left untreated, long-term conditions could become extremely severe.
What Causes a Low Resting Heart Rate?
There are multiple causes of a low resting heart rate also referred to as bradycardia that include:
Athletic Training: With athletic training, one of the possible reduced resting heart rates is in the case of the endurance athlete (runners, cyclists, and swimmers), because of the high degree of cardiovascular fitness. Exercising regularly may cause a shift in the structure and performance of the heart, making it more efficient to pump blood with fewer beats per minute.
Age: As individuals grow older, their heart rate slows down. This is partly because of alterations in the conduction system and electrical activities of the heart, and alteration of the health of the entire cardiovascular.
Some drugs: Some drugs, including antiarrhythmic drugs, calcium channel blocker drugs, and beta-blockers, are side effects that slow the heart rate. These drugs are usually applied in the treatment of conditions that include high blood pressure, irregular heart rhythm and angina.
Some medical conditions: Some medical conditions may lead to bradycardia by interfering with, or impairing, the electrical system of the heart, or decreasing its capacity to either produce or transmit electrical impulses. They might include such conditions:
Sick sinus syndrome: A set of heart rhythm disorders that are marked by anomalous electrical activity in the sinus node, the natural pacemaker of the heart.
Heart block: This is a condition where electrical impulses transmitting the heartbeat are blocked partially or totally between the upper chambers (atria) and the lower chambers (ventricles) of the heart.
Hypothyroidism: A disorder whereby the thyroid gland fails to synthesise sufficient thyroid hormones that, in turn, slow metabolism and heart rate.
Electrolyte imbalances: Potassium, calcium, or magnesium in the blood may have abnormal levels and thus influence the electrical activity of the heart and cause bradycardia.
Bradycardia-tachycardia syndrome: A disease that is characterised by high heart rates and slow heart rates, which usually happen as a result of the electrical system of the heart malfunctioning.
Sleep: When one is sleeping, particularly at the deep sleep stages, the heart rate generally slows down. This belongs to the physiological reaction of the body to relaxation and restorative sleep.
To Conclude…
Keeping an eye on our Resting Heart Rate is vital since it is considered an accurate measure of various aspects of our wellbeing such as overall heart function, normal functioning of the body, other conditions/diseases, etc. We should always keep a close watch on our Resting Heart Rate because this is an important way of being able to assess whether we have a normal or abnormal heart rate.
When the Resting Heart Rate reaches or exceeds the ‘danger zone’, this indicates that we may be experiencing a serious problem that would require our urgent attention. If you have any additional symptoms at this time, you should get immediate medical help as quickly as possible.
There are three main factors that determine an individual's resting heart rate; they include: lifestyle (such as exercise routine), genetics (such as family history) and any related disease(s). In addition to these three influences, the majority of medications that we take on a regular basis may also change our normal heartbeat pattern. Because of this, it is extremely important for us to inform our doctor on a regular basis of all medications that we have taken or are currently taking.