This can create a cycle in which anxiety and palpitations reinforce each other.
Relaxation techniques, controlled breathing, adequate sleep, and professional support for persistent anxiety may help.
However, it is important not to assume that every episode of a racing heart is caused by anxiety. Medical conditions can produce similar symptoms, and a healthcare professional may need to evaluate unexplained episodes.
2. Too much caffeine
Coffee, tea, energy drinks, pre-workout supplements, and some soft drinks contain caffeine.
Caffeine is a stimulant that affects the central nervous system. In sensitive individuals, it can cause temporary increases in heart rate, nervousness, and palpitations.
The effect depends on several factors:
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The amount consumed.
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Individual sensitivity.
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How quickly caffeine is consumed.
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Whether it is combined with other stimulants.
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Sleep quality.
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Certain medications or health conditions.
Some people can drink several cups of coffee without noticing any symptoms. Others may experience palpitations after a relatively small amount.
Energy drinks deserve particular attention because they may contain substantial amounts of caffeine and other stimulating ingredients.
Combining energy drinks with coffee, stimulant supplements, or certain medications may increase the likelihood of unpleasant cardiovascular symptoms.
If you notice that your heart races after consuming caffeine, consider reducing your intake and observing whether symptoms improve.
Avoid consuming large amounts of caffeine late in the day, especially if it interferes with sleep.
People with recurring palpitations should discuss caffeine use with their healthcare professional rather than assuming that reducing coffee alone will solve the problem.
3. Dehydration
Water plays an essential role in maintaining blood volume and supporting normal circulation.
When you become dehydrated, the amount of fluid circulating in your bloodstream may decrease.
Your heart may respond by beating faster to help maintain adequate blood flow.
Dehydration can develop because of:
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Insufficient water intake.
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Excessive sweating.
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Hot weather.
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Fever.
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Vomiting.
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Diarrhea.
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Prolonged physical activity.
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Certain medications, including diuretics.
Possible signs include dry mouth, thirst, dark urine, reduced urination, dizziness, fatigue, and weakness.
A person who becomes dehydrated may notice a rapid heartbeat when standing up or moving around. In more significant cases, the heart rate may remain elevated even while resting.
Drinking fluids regularly can help prevent dehydration.
However, people with heart failure, advanced kidney disease, or other conditions requiring fluid restrictions should follow their medical team's advice rather than increasing fluid intake without guidance.
If dehydration is severe or accompanied by fainting, confusion, inability to keep fluids down, or other serious symptoms, medical attention is necessary.
4. Lack of sleep and exhaustion
Sleep is essential for maintaining normal cardiovascular and nervous system function.
When you consistently sleep too little, your body may experience increased stress responses and changes in hormone regulation.
This can make you more sensitive to palpitations.
Sleep deprivation may also increase your reliance on caffeine, creating another possible trigger.
Some people notice a racing heartbeat after several nights of poor sleep, particularly when combined with emotional stress, irregular meals, or dehydration.
Improving sleep habits may help reduce these episodes.
Try to maintain a consistent bedtime, limit stimulating activities before sleep, reduce late-day caffeine consumption, and create a quiet sleeping environment.
Most adults need at least seven hours of sleep each night, although individual requirements vary.
If you regularly experience difficulty sleeping, loud snoring, choking sensations during sleep, or severe daytime fatigue, discuss these symptoms with a healthcare professional.
Conditions such as sleep apnea can affect cardiovascular health and may contribute to abnormal heart rhythms.
5. Anemia and low iron levels
Anemia occurs when the blood does not have enough healthy red blood cells or sufficient hemoglobin to carry oxygen effectively.
Hemoglobin is a protein inside red blood cells that transports oxygen from the lungs to the body's tissues.
When oxygen delivery becomes less efficient, the heart may compensate by pumping faster.
This can cause a rapid heartbeat, including during periods of rest.
Other possible symptoms include:
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Persistent fatigue.
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Weakness.
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Pale skin.
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Shortness of breath.
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Dizziness.
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Headaches.
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Cold hands and feet.
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Reduced exercise tolerance.
Iron deficiency is a common cause of anemia, but anemia can also result from vitamin B12 deficiency, folate deficiency, chronic inflammation, blood loss, inherited conditions, and other medical problems.
Heavy menstrual bleeding, gastrointestinal bleeding, and inadequate dietary iron intake may contribute to iron deficiency in some individuals.
A blood test, particularly a complete blood count, can help identify anemia. Additional tests may be needed to determine its cause.
Do not begin taking high-dose iron supplements simply because you suspect that low iron is causing your palpitations.
Too much iron can be harmful, and not every type of anemia responds to iron treatment.
A healthcare professional can determine whether supplementation is appropriate and identify the underlying problem.
6. Thyroid problems
The thyroid is a small, butterfly-shaped gland located at the front of the neck.
It produces hormones that influence metabolism, energy use, temperature regulation, and several cardiovascular functions.
When the thyroid produces too much hormone, a condition known as hyperthyroidism, the body may become unusually stimulated.
The heart can respond by beating faster, sometimes even when a person is sitting quietly.
Other symptoms may include:
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Unexplained weight loss.
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Increased sweating.
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Heat intolerance.
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Trembling hands.
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Nervousness or irritability.
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Difficulty sleeping.
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Frequent bowel movements.
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Muscle weakness.
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Changes in menstrual patterns.
Some people develop an irregular heart rhythm, including atrial fibrillation.
Hyperthyroidism is not the only thyroid-related issue that can affect heart rate, but it is an important cause of persistent rapid heartbeat.
Doctors may evaluate thyroid function through blood tests measuring thyroid-stimulating hormone and thyroid hormones such as free T4.
Treatment depends on the underlying cause and may include medication, radioactive iodine therapy, or surgery in selected cases.
If a racing heartbeat is accompanied by unexplained weight loss, tremors, excessive sweating, or persistent heat intolerance, thyroid testing may be worth discussing with a healthcare professional.
7. Medication and stimulant effects
Certain medications and supplements can increase heart rate or trigger palpitations.
Examples include:
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Some decongestants used for nasal congestion.
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Certain asthma medications.
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Some prescription stimulants.
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Thyroid hormone replacement when the dose is too high.
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Certain weight-loss products.
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Some herbal or energy supplements.
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Nicotine-containing products.
Not everyone experiences these effects, and the risk depends on the specific substance, dose, and individual health.
Combining several stimulant products may increase the likelihood of symptoms.
If your palpitations begin after starting a new medication or changing a dose, contact the prescribing healthcare professional.
Do not stop prescribed medication abruptly without medical advice.
A doctor or pharmacist can review your medication list and determine whether an alternative, dose adjustment, or additional testing is appropriate.