Why Is My Heart Racing at Night?

You are lying in bed, the house is quiet, and suddenly you can feel your heart thumping fast in your chest or hear it in your ears. It is unsettling, and it often feels worse at night simply because there is nothing else to distract you.

This article explains the common and less common reasons your heart might race at night, how to tell them apart, and which symptoms mean you should call 911. It can help you decide what to do next, but it cannot diagnose you. Only a medical assessment, often including a heart tracing, can do that.

What counts as a racing heart?

A racing heart usually means a heart rate above 100 beats per minute at rest, which doctors call tachycardia, or a sense that your heart is pounding, fluttering or skipping, which doctors call palpitations. You can have one without the other.

According to the American Heart Association, a normal resting heart rate for most adults is 60 to 100 beats per minute. During sleep it usually drops lower. Our article on your resting heart rate explains what is typical and how fitness, age and medicines change it.

A fast heartbeat is one of many everyday body signals, and the physical health guide puts it in the wider context of heart and whole-body health.

Why do I notice my heartbeat more at night?

You often notice your heartbeat more at night because the room is quiet, you are still, and lying on your side, especially your left side, can bring the heart closer to the chest wall. A heartbeat that would go unnoticed during the day can feel loud in bed.

That awareness alone can create a loop: you notice your pulse, feel worried, and the worry releases adrenaline, which speeds your heart up further. This does not mean the sensation is imagined. It means attention and anxiety can amplify a real, often harmless, change.

What are the common causes of a racing heart at night?

The most common causes are everyday triggers rather than heart disease: anxiety, stimulants, alcohol, late meals, dehydration and disrupted sleep. The table below sets them out with the clues that point to each.

Cause	Typical clues	What may help
Anxiety or stress	Racing thoughts, worry, tight chest, often when trying to fall asleep	Slow breathing, a wind-down routine, treating the anxiety
Caffeine	Coffee, tea, soda, energy drinks or pre-workout in the afternoon or evening	Cut back and stop earlier in the day
Alcohol	Fast heartbeat a few hours after drinking, often with broken sleep	Drink less, especially near bedtime
Nicotine or other stimulants	Smoking, vaping or decongestant medicines in the evening	Avoid before bed; ask about quitting support
Large or late meal	Pounding heartbeat after a heavy dinner close to bedtime	Earlier, lighter evening meals
Dehydration	Thirst, dark urine, a hot day or exercise	Drink fluids through the day
Nightmares or night terrors	Waking suddenly, frightened, with a fast pulse	Address stress and sleep; see your doctor if frequent
Fever or infection	Feeling hot, unwell, sweaty	Treat the illness; see a doctor if severe

Anxiety and panic

Anxiety is one of the most common reasons for a racing heart in bed. Some people also have nocturnal panic attacks, which are sudden surges of intense fear that wake you from sleep with a pounding heart, sweating and shortness of breath. Because the symptoms overlap with heart problems, our piece on telling a panic attack from a heart attack walks through the differences.

Caffeine and alcohol

Caffeine is a stimulant that can stay in your system for hours, so an afternoon coffee can still affect you at bedtime. The FDA cites 400 mg a day as an amount not generally linked with negative effects in healthy adults, but sensitivity varies a lot. Alcohol can make you drowsy at first, then raise your heart rate and disturb sleep later in the night.

Which medical conditions can make your heart race at night?

Several medical conditions can cause a fast or irregular heartbeat at night, and they are worth checking if the episodes are frequent, sudden or come with other symptoms. A doctor can test for most of them.

Condition	What it is	Clues
Supraventricular tachycardia (SVT)	A rhythm problem in the upper heart that causes sudden, very fast regular beats	Starts and stops abruptly, like a switch
Atrial fibrillation (AFib)	An irregular, often fast rhythm in the upper chambers of the heart	Irregular pulse, breathlessness, tiredness; more common with age
Overactive thyroid (hyperthyroidism)	The thyroid makes too much hormone	Weight loss, feeling hot, tremor, anxiety
Sleep apnea	Breathing repeatedly stops and starts during sleep	Loud snoring, gasping, morning headaches, daytime sleepiness
Anemia	Too few healthy red blood cells to carry oxygen	Tiredness, pale skin, breathlessness on exertion
Low blood sugar	Blood glucose drops too low, usually with diabetes medicines	Sweating, shakiness, waking hungry or confused
Low blood pressure or blood loss	The heart speeds up to keep blood flowing	Dizziness, especially on standing

According to NHLBI, atrial fibrillation raises the risk of stroke, which is one reason an irregular racing heartbeat should be checked rather than ignored. Sleep apnea is also linked with heart rhythm problems and high blood pressure. If you have had a high reading, the guide to blood pressure readings explains the AHA categories.

Can medicines and supplements cause a racing heart?

Yes, a number of medicines and supplements can speed up your heart. Common examples include decongestants such as pseudoephedrine, some asthma inhalers, thyroid hormone at too high a dose, stimulant medicines for ADHD, and some weight-loss or "energy" supplements.

Stopping some heart and blood pressure medicines suddenly, such as beta blockers, can also cause a rebound fast heartbeat. If your symptoms started after a new medicine or dose change, talk to your doctor or pharmacist before changing anything yourself.

Is a racing heart at night dangerous?

A racing heart at night is usually not dangerous, especially if it is short-lived, has an obvious trigger and you otherwise feel well. It is more concerning when it comes with chest pain, fainting, severe breathlessness, or when it is very fast, irregular or happens often without a clear cause.

People with known heart disease, a family history of sudden cardiac death at a young age, or episodes during exercise should be assessed promptly. The same goes for anyone over 65 who notices an irregular pulse, since AFib becomes more common with age.

What can you do when your heart is racing in bed?

If you feel well otherwise, you can often settle a racing heart by calming your body and removing obvious triggers. These steps are low risk and worth trying.

1. Sit up and breathe slowly. Breathe in gently through your nose and out for longer than you breathed in, for a few minutes.
2. Check your pulse. Count beats for 30 seconds and double it, and notice whether the rhythm is regular or irregular. A smartwatch reading is useful to share with your doctor but is not a diagnosis.
3. Drink some water if you might be dehydrated.
4. Change position. Lying on your back or right side can make your heartbeat feel less prominent.
5. Get out of bed briefly if anxiety is building, and do something calm in dim light until you feel sleepy.

Over the following weeks, cut back on caffeine after midday, limit alcohol, avoid heavy meals close to bed, and keep a regular sleep schedule. Regular physical activity strengthens the heart over time, and the Physical Activity Guidelines for Americans recommend 150 to 300 minutes of moderate activity a week plus two strength days. Our article on why walking is underrated is an easy place to start.

Habits that help prevent nighttime episodes

Prevention mostly means taking the common triggers out of your evenings. Small, steady changes tend to work better than sudden overhauls, and they also improve sleep, which in turn helps steady your heart rate.

• Keep caffeine to the morning, and check labels on sodas, teas, energy drinks and pain relievers that contain it.
• If you drink alcohol, have less and finish earlier in the evening, with water alongside.
• If you smoke or vape, talk to your doctor about quitting support, since nicotine is a stimulant.
• Leave two to three hours between your last large meal and bedtime when you can.
• Build in a short wind-down routine, such as reading or a warm shower, to ease the shift from a busy day into rest.
• Review any cold medicines or supplements you take in the evening with a pharmacist.

If anxiety seems to drive most of your episodes, treating the anxiety itself, for example with talk therapy, often reduces how often your heart races at night.

How will a doctor find out why your heart races?

A doctor will usually start with questions about your symptoms, a physical exam and an electrocardiogram (ECG or EKG), a quick test that records your heart's electrical activity. Because night episodes rarely happen in the office, longer monitoring is common.

• Holter monitor: a portable ECG worn for a day or two.
• Event monitor or patch: worn for weeks, recording when symptoms happen.
• Blood tests: to check thyroid function, blood count and electrolytes.
• Echocardiogram: an ultrasound of the heart's structure.
• Sleep study: if sleep apnea is suspected.

Keeping a short diary helps: note the time, what you ate or drank, how long the episode lasted, your pulse, and any other symptoms.

When should you see a doctor or call 911?

See your doctor if your heart races at night often, if episodes start and stop suddenly, if your pulse feels irregular, or if you have a history of heart disease or thyroid problems. Book a visit too if you snore loudly or wake gasping.

Call 911 or go to the emergency room if a racing heart comes with any of these:

• Chest pain, pressure or tightness, or pain spreading to the arm, jaw, neck or back
• Fainting or nearly fainting
• Severe shortness of breath
• Sudden weakness or numbness on one side, facial drooping or trouble speaking, which can be signs of stroke
• Confusion, or a very fast heart rate that does not settle with rest

Do not drive yourself to the hospital if you have these symptoms. A racing heart at night is usually explainable and manageable, but getting the serious causes checked gives you peace of mind and, when needed, effective treatment.