What’s Causing Your Elevated Heart Rate?

When you're active, excited or under stress, a quickened pulse is normal. But if your heart is racing while you're resting, it's a good idea to look into the cause. In most cases, it's something simple and easily treatable. Occasionally, though, the cause can be more worrisome.

A resting heart rate of 60 to 100 beats per minute is considered normal for adults. But it can vary based on your age and fitness level. For example, well-conditioned athletes can have a resting heart rate as low as 40 beats per minute, according to the American Heart Association.

"Whenever you get a consistently higher heart rate, more than 100 in an otherwise healthy person, at rest, it's something that may need to be evaluated," says Rakesh Gopinathannair, MD, an electrophysiologist with the Kansas City Heart Rhythm Institute and a professor of medicine at the University of Missouri-Columbia.

The list of things that can cause your heart to speed up is long. Doctors typically consider these broad categories:

1. Non-Heart-Related Causes

• Illness: Your heart rate increases when you have an infection or fever, states the Mayo Clinic.
• Psychological causes: Anxiety, panic attacks and insomnia can all be culprits.
• Blood chemistry: If you're anemic or dehydrated, your heart has to work harder.
• Hormones: A hyperactive thyroid gland is a common cause.
• Medications: Albuterol inhalers for asthma, ADHD medications and over-the-counter decongestants can all be causes, according to the Cleveland Clinic and the U.S. National Library of Medicine. If you suddenly stop taking a type of medication called a beta blocker, (which slows your heart rate), this can cause your heart rate to bound upward.
• Recreational drugs: Cocaine and methamphetamines can raise your heart rate, states the American Heart Association.

2. Heart-Related Causes

• Arrhythmias: These are abnormal heart rhythms, often caused by problems with the heart's electrical signals. Arrhythmias can cause heartbeats that are abnormally fast (tachycardia), abnormally slow (bradycardia) or irregular, according to the American Heart Association. The most common type of arrhythmia that causes a fast heart rate is atrial fibrillation.
• Structural problems: A narrowed valve or another physical problem with your heart can cause it to have to work harder to circulate the oxygen-rich blood your body needs.
• Heart failure: "If your heart doesn't pump well, then you have less amount of blood that the heart pumps," says Dr. Gopinathannair. "So, the body compensates by increasing the heart rate."

Read more: The 14 Best Foods for Your Heart

An occasional fast pulse or pounding sensation that doesn't last long, known as a palpitation, typically isn't something to worry about.

But, says Dr. Gopinathannair, if your heart is going at a sustained 170 or 180 beats a minute and you're having rapid palpitations, pounding and associated symptoms like shortness of breath, chest pain or dizziness, you may need an immediate evaluation in the ER. That's because some types of arrhythmias can lead to life-threatening complications, including stroke, heart failure and cardiac arrest.

If your heart rate is more like 105 or 110 beats a minute and you feel otherwise normal except for occasional palpitations, Dr. Gopinathannair advises going to an urgent care center or seeing your primary care doctor.

Another reason to see a doctor is if you have episodes of fast heart rate that are persistent or frequent or that involve other sensations, says Dr. Gopinathannair. Examples are having a regular fast heart rate of 100 beats per minute or symptoms such as skipped beats or a flip-flopping sensation.

Read more: My Heartbeat Skips After Exercising

Your doctor is likely to begin your evaluation with a physical exam, health history and an electrocardiogram (EKG or ECG), states the American Heart Association. If you're not having an abnormal or elevated heart rate at the time, the machine may not pick up a problem.

Your doctor may instead recommend you wear a portable EKG for a week or more, according to the Heart Rhythm Society. This provides a continuous readout that will catch a high heart rate whenever it happens.