Have you ever felt your pulse and noticed that it seems particularly fast? Maybe your doctor has told you that your heart rate is fast after measuring your pulse. You know exercise can make your heart pump harder than usual, but what does it mean if your heart rate is fast even when you haven’t exercised recently?

Specific medications, emotions, or medical conditions can increase your heart rate, even while you’re at rest. Your body size can also influence your heart rate — obesity may be associated with a faster resting heart rate.

In this article, we’ll talk about different ways obesity can affect your heart rate and what a fast heart rate means for your health.

What Your Heart Rate Means

When a healthcare professional tells you that you have a fast pulse, they’re usually talking about your resting heart rate. Your resting heart rate is the number of heartbeats that occur within the span of one minute when you’re rested and feeling calm.

According to the American Heart Association, a typical resting heart rate can range from 60 to 100 beats per minute (bpm).

A resting heart rate above 100 bpm may or may not indicate a problem with your cardiovascular health. This type of fast heart rate is called tachycardia, and it can be brief or ongoing.

A resting heart rate lower than 60 bpm is called bradycardia and is common in athletes. For some people, a low bpm rate may be a sign of a healthy heart muscle that doesn’t have to work very hard to pump blood.

How Obesity Affects Your Heart Rate

Obesity can involve many body changes that impact your heart rate and blood pressure.

Sympathetic Nervous System Activation

A part of your nervous system called the autonomic nervous system is responsible for controlling your heart rate and other processes that happen automatically. This includes your blood pressure and digestion.

Low-grade chronic inflammation, common with obesity, can affect how autonomic nerves function. This may lead to a higher resting heart rate.

You can also look to the sympathetic nervous system to find out why obesity can raise your heart rate. The sympathetic nervous system is a part of the autonomic nervous system. It produces your body’s fight-or-flight response.

Activated by stress, danger, or exercise, your sympathetic nervous system puts your body into survival mode. Two neurotransmitters active in the sympathetic nervous system, called norepinephrine and epinephrine, cause changes in your body meant to help you stay alert and ready to react to possible threats. This includes making your heart beat faster.

Obesity often involves chronic (ongoing) activation of the sympathetic nervous system. When your sympathetic nervous system is constantly “on,” it can cause tachycardia or various heart arrhythmias (problems with heart rhythm).

A Higher Metabolic Demand

When you have a larger body, your heart must work harder to circulate blood via your blood vessels. You have a higher blood volume, which means your heart pumps more blood to ensure your organs and tissues get the oxygen and nutrients they need to function.

Overall, this creates a higher metabolic demand. Your heart muscle may grow to accommodate these needs, and it may pump harder and faster to ensure your body’s needs are met.

Connecting Heart Rate and Blood Pressure

Your heart rate and blood pressure are closely related. In people with obesity, many of the same factors impact heart rate and blood pressure at the same time. Obesity can increase your risk of tachycardia and hypertension (high blood pressure), which are both heart disease risk factors.

Factors That Increase Both Heart Rate and Blood Pressure

An overactive sympathetic nervous system, which is common with obesity, can lead to high blood pressure and a faster heart rate. But the connections between hypertension and tachycardia in obesity don’t stop there.

Both high blood pressure and an elevated heart rate can occur when your heart works harder and encounters more vascular resistance. Both can also worsen because of other obesity-related conditions and body changes, including those listed below.

Insulin Resistance

Insulin is a hormone your body uses to move glucose (sugar) from your blood into your cells so your cells can use the sugar as a source of energy. If you’re insulin-resistant, your cells are less receptive to the hormone, and glucose builds up in your bloodstream.

Experts believe insulin resistance may play a role in increasing your resting heart rate. Insulin resistance is common among people living with obesity and can also contribute to increases in blood pressure.

Sleep Apnea

Obesity is a risk factor for obstructive sleep apnea (OSA), which occurs when your airway is repeatedly compressed or blocked as you sleep. As a result, you wake up repeatedly and don’t get the restorative sleep your heart needs to function well.

Over time, OSA can affect your heart rate and contribute to hypertension.

High Heart Rate and Resistant Hypertension

Resistant hypertension occurs when your high blood pressure doesn’t improve despite being treated with antihypertensives (medications to treat hypertension). To be diagnosed with resistant hypertension, your blood pressure must not improve after six months of taking three or more blood pressure medications.

Research shows that reduced heart rate variability (HRV), a measure of the variation in time between each heartbeat, is associated with an increased risk for resistant hypertension. Obesity is linked with reduced HRV.

A higher HRV means there are changes between the amount of time between each of your heartbeats. Those changes are small enough to require special instruments to detect, but they’re significant.

Having a high HRV means your heart is more adaptable to stress and change. A low HRV is common in people with fast resting heart rates and can predict a higher risk of future heart problems.

A Faster Heart Rate and Your Cardiovascular Risk

Obesity is linked to an increased risk of cardiovascular diseases, and tachycardia can compound those risks. Certain types of tachycardia can damage your kidneys, liver, and heart.

If you have a particularly fast heart rate, you may be at a higher risk for:

• Blood clots
• Heart attack
• Cardiomyopathy (a weakened heart)
• Stroke
• Cardiac arrest

Other obesity-related factors, like high blood pressure and OSA, can increase these risks too. It’s important to work closely with your doctor to manage your heart health and any co-occurring conditions you have.

Talk to Your Doctor

If you have any concerns about your heart rate and the health risks that can come with tachycardia, talk to your doctor. Your healthcare provider can take your pulse in the office and tell you if your resting heart rate is high.

They may also use an electrocardiogram (ECG) to check your heart rate variability and learn more about how your heart is functioning.

Your doctor may recommend various treatments and lifestyle changes to help control your heart rate, blood pressure, and overall health and wellness.

However, there may be times when immediate medical care is needed. Seek medical attention right away if you have a fast heart rate coupled with other heart-related symptoms such as:

• A pounding heart
• Shortness of breath
• Chest pain or pressure
• Dizziness, lightheadedness, or fainting

Join the Conversation

On MyObesityTeam, people share their experiences with obesity, get advice, and find support from others who understand.

Have you noticed heart rate changes while living with obesity? Let others know in the comments below.