Many factors can cause a person to wake up with a racing heart, including stress, sleep deprivation, sleep apnea, and changes in blood sugar levels.

Sometimes, people may wake up feeling like their heart is beating very fast or pounding in the chest. They may also feel shaky or anxious when this happens.

“Tachycardia” is the medical term for a rapid heart rate. It is not always a matter of concern but can indicate a medical condition. If a person’s heart rate changes, they can seek medical advice to rule out any serious issues.

This article discusses why someone may wake up with their heart racing and when to contact a doctor.

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Anxiety and stress can trigger the release of hormones in the blood that raise the heart rate. Statistics suggest that around 31% of heart palpitation cases may be due to a mental factor such as stress, anxiety, or internal conflict.

Find 10 natural remedies for stress and anxiety.

Blood sugar levels can affect a person’s heart rate.

A rapid heart rate is one symptom of high blood sugar (hyperglycemia). For people with diabetes, consuming sugary foods before a nap or before bed may cause them to wake up with a racing heart.

Research from 2017 also suggests that low blood sugar levels can increase the risk of arrhythmia. Low blood sugar triggers the release of epinephrine in the body. Epinephrine is a hormone linked to the “fight-or-flight” response, which can affect heart rate.

Learn how to manage blood sugar levels.

Some experts say that caffeine consumption can increase heart rate. Caffeine is present in coffee, tea, soda, and some medications.

Researchers suggest this may be true for some people, specifically those with a particular gene.

However, a 2021 study that looked at data from more than 300,000 people found no evidence that caffeine increased the risk of heart rate changes. Instead, the findings suggested that drinking coffee might reduce this risk by 3%.

The American Heart Association advises people to consume coffee in moderation.

Learn whether it is possible to overdose on caffeine.

Dehydration can affect the heart and may lead to an irregular heartbeat. Too little fluid in the body is known as “hypohydration.” It can lead to low blood pressure. The body compensates by producing additional hormones to speed up the heart.

Learn more about dehydration.

Research from 2017 shows that consuming alcohol in excess can lead to arrhythmia and a rapid heart rate.

It takes several hours for the body to process large amounts of alcohol, and the effects of drinking in the evening can continue throughout the night and into the morning.

Learn about the health risks of chronic heavy drinking.

A nightmare is a disturbing dream that can cause physical symptoms, such as respiratory difficulties. This may cause a person to wake up with a racing heart. They may also experience sweating and shaking.

Night terrors can also cause individuals to wake up feeling panicked with a racing heart.

Learn more about night terrors.

Narcolepsy is a sleep disorder that includes:

The condition also has links with diabetes, heart disease, high cholesterol, and high blood pressure. Most people’s heart rate dips when they sleep. In people with narcolepsy, it may increase.

Learn more about narcolepsy.

A lack of sleep may also cause a person to feel that their heart rate is higher than usual.

Sleep disturbances or not getting enough sleep can cause several health issues. The next day, the person may also feel that their heartbeat is slightly faster.

Adults who sleep less than 7 hours per night may be more likely to experience health issues, such as heart attack, asthma, and depression.

Learn more about sleep deprivation.

Sleep apnea is when a person repeatedly stops breathing while they sleep. This can lower oxygen levels and put extra stress on the heart. It may also cause a racing heartbeat.

Research from 2017 suggests sleep apnea may also contribute to new appearances of atrial fibrillation (AFib).

Read about the symptoms of sleep apnea.

People with iron deficiency anemia do not have enough healthy red blood cells circulating in their bodies. This can cause various symptoms, including changes in heart rate.

Learn how to increase a red blood cell count.

Waking up with a racing heart may also be due to hormone changes during the menstrual cycle and menopause. More specifically, a racing heart can occur due to changing levels of the hormones estrogen and progesterone.

Around menopause, declining estrogen levels can lead to palpitations. Palpitations may also occur during hot flashes.

Learn more about palpitations and menopause.

Changes in the body’s temperature, for example, during a fever, may also cause changes in heart rate.

A 2021 study of people in ICU found that for every 33.8°F (1°C) body temperature rise in females, their heart rate increased by 9.5 beats per minute on average. For males, it was 7.2 beats.

Learn more about fever.

A fast or irregular heart rate may be a side effect of various medications, including:

Anyone taking medications should speak with a doctor about possible side effects affecting the heart.

A person should seek help for any change in heart rhythm or heart rate as it can signal an underlying issue.

A doctor may perform tests and order a Holter monitor. This records heart activity. It can monitor heart rhythms and help with diagnosis.

A person needs urgent medical attention if they have a history of heart disease or signs of a heart attack, such as chest pain.

Learn how to stop heart palpitations.

Below are answers to some common questions about heart palpitations at night.

I cannot sleep because of palpitations. What should I do?

Anyone who often notices changes in heart rhythm should seek medical advice as they may indicate an underlying health issue. If palpitations are due to stress, breathing exercises or meditation may help. If a person takes medication for a heart condition and has palpitations, they should contact a doctor. The medication may need a review.

Why do I get palpitations at night?

This can happen if a person has a heart condition, such as AFib. Other possible causes of arrhythmia or a rapid heart rate include:

  • sleep apnea
  • narcolepsy
  • a lack of sleep
  • alcohol use
  • stress
  • changes in blood sugar
  • hormonal fluctuations

Waking up with a racing heart is not necessarily a cause for concern, but it is best to seek medical advice.

Causes include stress, dehydration, sleep deprivation, and hormone changes.

A doctor may determine that no treatment is necessary. However, they may also recommend tests or refer someone to a specialist for further investigation.