What Causes Heart Palpitations?

Your heart pounds, flutters, or seems to skip beats. You might call these feelings palpitations. Although they can feel scary, most aren't serious and rarely need treatment. Knowing what makes your heart race can help you not panic when it happens and know when to call your doctor.

Intense emotions can trigger the release of hormones that speed up your heartbeat. Your body gets ready to face a threat, even if you're not in danger. Panic attacks are intense bouts of fear that can last a few minutes. Symptoms include a racing heart, sweating, chills, trouble breathing, and chest pain. A panic attack can feel like a heart attack. If you're not sure which one you're having, get medical help.

Working out is good for you. And a brisk run or intense indoor cycling class will naturally make your heart beat faster. That helps your heart pump more blood to power your muscles through the workout. If your heart flutters or pounds, it could be because you haven't worked out in a while and you're out of condition. An irregular heartbeat, or arrhythmia, can also cause palpitations when you exercise.

Does your heart beat faster after your morning latte? Caffeine is a stimulant that raises your heart rate, whehther you get it from coffee, soda, an energy drink, tea, chocolate, or another source. One study found that caffeine from coffee, tea, and chocolate isn’t likely to cause palpitations in people with healthy hearts. But experts don't know whether it might trigger them in people with heart rhythm problems. 

The addictive chemical in cigarettes and other tobacco products, nicotine raises your blood pressure and speeds up your heart rate. Quitting smoking is one of the best things you can do for your heart, though it might not slow your heartbeat right away. Patches and other nicotine replacement products can make your heart race. Palpitations can also be a symptom of nicotine withdrawal, but they should stop within 3 to 4 weeks after you quit.

Women might notice that their heartbeat speeds up when they have their period, they're pregnant, they’re close to menopause, or they're in menopause. The reason: hormone levels. The boost in heart rate is usually temporary and no reason for worry. If you're pregnant, palpitations can also happen if you're anemic, which means you don’t have enough red blood cells that carry oxygen throughout your body.  

When you have a fever during an illness, your body uses energy at a faster pace than usual. This can set off palpitations. Usually your temperature needs to be above 100.4 F to affect your heart rate.

Have you ever noticed that you feel shaky, cranky, and weak when you've skipped a meal? It can also lead to palpitations. When your blood sugar level drops, your body releases stress hormones like adrenaline to prepare for an emergency food shortage. Adrenaline speeds up your heart rate.

Your thyroid is a butterfly-shaped gland in your neck. It makes hormones that help manage your metabolism and other things. An overactive thyroid (called hyperthyroidism) can make too much thyroid hormone. That can speed up your heart so much that you feel it beating in your chest. Taking too much thyroid hormone to treat an underactive thyroid gland (called hypothyroidism) can also rev up your heartbeat.

Sometimes an irregular heart rhythm, called an arrhythmia, causes palpitations.

• Atrial fibrillation, or AFib, happens when the heart's upper chambers, called the atria, flutter instead of beating normally.
• Supraventricular tachycardia is an abnormally fast heartbeat that starts in the heart's upper chambers.
• Ventricular tachycardia is a fast heart rate due to faulty signals in the heart's lower pumping chambers, called the ventricles.

If you drink a lot, or just have more than usual, you might feel your heart beating faster or fluttering. It often happens on holidays or weekends, when people drink more, earning it the nickname of "holiday heart syndrome.” But for some people, it can happen even when they only drink a little bit.

Premature ventricular contractions (PVCs) are extra heartbeats. They happen when your heart's ventricles squeeze too soon. The extra beat throws off your heart's normal rhythm and makes it flutter, pound, or jump in your chest. If your heart is healthy, occasional PVCs are nothing to worry about. But you might need treatment if you have heart disease and you get these extra beats often.

Illegal drugs like amphetamines, cocaine, and ecstasy are dangerous to the heart. Cocaine boosts blood pressure, raises heart rate, and damages the heart muscle. Amphetamines stimulate the nervous system, which ramps up your heartbeat. Ecstasy triggers the release of a chemical called norepinephrine, which makes the heart beat faster.

If you're healthy, you probably don't need to worry about palpitations that happen once in a while and last only a few seconds. But make a doctor's appointment if they come more often or you also have symptoms like these:

• Chest pain or pressure
• Shortness of breath
• Dizziness
• Fainting

These tests can help your doctor figrue out what's going on:

• Electrocardiogram (ECG). This test looks for problems with the electrical signals that control your heart rhythm.
• Holter monitor. You wear this portable ECG for 24 to 72 hours at a time. It can find heart rhythm problems and any patterns that might need more tests.
• Event Monitor. You wear this device for several weeks. It records your heart rhythm when you press a button while having symptoms.
• Echocardiogram. This test uses sound waves to make pictures of your heart. It can find problems with your heart's structure.