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Why is my heart beating so fast while resting?

There are several potential reasons why your heart may be beating faster than normal when you are at rest:

Anxiety or stress

Feeling anxious or stressed can activate your body’s fight-or-flight response, which causes your heart to beat faster. This prepares your body to deal with perceived threats. Things like work, relationships or finances can trigger anxiety. Try relaxing activities like deep breathing, meditation or yoga to help calm your mind.

Caffeine or nicotine

Consuming stimulants like caffeine or nicotine can temporarily increase your heart rate and make you feel like it’s beating too fast. Caffeine is in coffee, tea, soda and energy drinks. The effects usually wear off within a few hours. Cut back on caffeine and quit smoking to see if it helps.


When your body lacks fluid, your blood volume decreases. This makes it harder for blood to get to your heart, forcing it to pump faster to circulate blood through your blood vessels. Drink plenty of water and fluids like fruit juice to stay hydrated.


Having a higher body temperature when you’re sick with an infection or flu can raise your heart rate. This is your body’s natural response to help fight illness. Monitor your temperature and call your doctor if you have a fever over 101 F (38.3 C).


Anemia occurs when you lack healthy red blood cells to carry oxygen to your body’s tissues. Your heart has to beat faster to compensate for the reduced oxygen delivery. Anemia can be caused by iron deficiency, vitamin deficiencies or blood loss. See your doctor to check for anemia.

Thyroid disorders

Thyroid disorders like hyperthyroidism or hypothyroidism cause hormonal imbalances that can make your heart race or beat too slowly. Hyperthyroidism speeds up your metabolism, while hypothyroidism slows it down. Get your thyroid hormone levels tested if this could be the issue.

Medication side effects

Some medications can raise your heart rate as a side effect. These include decongestants, certain asthma medications and thyroid hormones. Review your medications with your doctor or pharmacist.

Heart arrhythmias

Abnormal heart rhythms like atrial fibrillation, atrial flutter and ventricular tachycardia can make your heart feel like it’s racing or pounding. These arrhythmias originate in the heart’s upper chambers or lower chambers. Treatment may include medications or procedures to regulate your heart rate.

Heart valve problems

Conditions like mitral valve prolapse or aortic stenosis can disrupt normal blood flow through your heart. This forces the heart to pump harder and faster to circulate blood properly. Your doctor can check for heart murmurs that may indicate a valve issue.

Congenital heart defects

Some people are born with structural heart problems that affect how the heart functions. This includes defects like septal defects, narrowed heart valves or problems with the heart’s electrical system that controls the heartbeat. Surgery may be done to repair certain defects.

Heart failure

With heart failure, the heart muscle is damaged or weakened. It cannot pump blood efficiently enough to meet the body’s needs. To compensate, it may beat faster when you’re at rest. Lifestyle changes and medications can help manage heart failure.

Coronary artery disease

A buildup of plaque in the heart’s arteries reduces blood flow to the heart muscle itself. To make up for the lack of oxygen and nutrients, the heart pumps faster to circulate blood through narrowed arteries. Managing risk factors like high blood pressure and high cholesterol can help prevent coronary artery disease.

Heart infection

In rare cases, infections from viruses or bacteria can inflame the heart muscle or sac around the heart, causing it to beat too fast. This includes conditions like myocarditis, pericarditis or endocarditis. Seek emergency care for symptoms like fever and chest pain.

When to see a doctor

In most cases, an occasional rapid heart rate while at rest is not dangerous, especially if it has an identifiable cause like anxiety or caffeine. But a consistently or excessively fast heart rate may indicate an underlying heart condition.

See your doctor to get your heart rate and rhythm checked if you experience:

  • A resting heart rate consistently over 100-120 beats per minute
  • Sudden rapid heart beats that come and go
  • A racing heart along with dizziness, lightheadedness or fainting
  • Shortness of breath or chest pain with a rapid heart rate
  • New, unexplained heart palpitations in someone over age 50

Your doctor can perform tests to determine what’s causing your heart to beat too fast. This may include an EKG to check for arrhythmias, blood tests to check thyroid function or anemia, or an echocardiogram to look at your heart structure and function.

Treatment will depend on the underlying cause. Your doctor may prescribe medications to regulate your heart rhythm or treat an overactive thyroid. For coronary artery disease, they may recommend surgery or stents to open blocked arteries.

When it’s normal

It’s common for your heart rate to temporarily rise in response to normal daily activities and stressors. This allows your body to meet increased energy demands when you exercise, have anxiety or become overheated. For most people, it’s normal for your resting heart rate to get up to 100-120 beats per minute during exercise or high stress.

Your heart rate variability can also change throughout the day – your heart may beat slightly faster when you wake up in the morning compared to at bedtime. It’s usually nothing to worry about if your heart rate returns to a normal resting pace of 60-100 beats per minute when you are relaxed.

Tips to slow a racing heart

If anxiety or stress is making your heart race, try these tips to activate your relaxation response and calm your mind and body:

  • Take slow, deep breaths in through your nose and out through your mouth
  • Listen to soothing music or nature sounds
  • Meditate or visualize a peaceful setting
  • Go for a walk outdoors
  • Take a warm bath or use a heating pad to relax muscles
  • Avoid consuming stimulants like caffeine, energy drinks or nicotine
  • Limit alcohol, which can trigger heart palpitations
  • Practice mindful activities like yoga, tai chi or qigong
  • Talk to a therapist or counselor about anxiety management

Making healthy lifestyle changes can also support normal heart rhythm and keep your heart beating steadily:

  • Stay well hydrated by drinking enough water daily
  • Follow a nutritious diet with fruits, vegetables and whole grains
  • Exercise regularly at a moderate intensity
  • Reach a healthy weight and keep it stable
  • Manage stress through self-care activities
  • Get enough quality sleep every night


Having your heart suddenly start beating fast can feel alarming. But in many cases, it’s a temporary reaction to stress, dehydration or stimulants. See your doctor to check for a potential heart condition if you have ongoing palpitations or a consistently rapid heart rate over 100 bpm at rest.

With anxiety or occasional stressors, try relaxing your body and mind through breathing techniques, meditation and other calming activities. Maintaining healthy lifestyle habits can also promote normal heart rhythm.