Caffeine, Anxiety, Heart Rhythm and Sleep: Effects and Who Is More Sensitive
What research and official bodies say about caffeine, anxiety, palpitations, heart rhythm and sleep, who is more sensitive, and when jitters or a racing heart need a clinician.
Content last updated . This page has not been medically reviewed.
Urgent first: when a racing heart is an emergency
Call 911 (US) for seizures, a rapid or dangerously erratic heartbeat, vomiting with confusion, or if someone seems seriously unwell after a large amount of caffeine or any concentrated caffeine product. The FDA lists these among the serious effects of pure and highly concentrated caffeine. [1] For poisoning advice in the US, Poison Help is 1-800-222-1222. See caffeine overdose and toxicity. If anxiety feels unmanageable or you are thinking of harming yourself, call or text 988 (US Suicide & Crisis Lifeline).The short answer
Caffeine can cause jitters, anxiety, a pounding heart and poor sleep, and some people are more sensitive than others. The FDA lists increased heart rate, heart palpitations, high blood pressure, insomnia or sleep disruption, anxiety and jitters among the signs of too much caffeine, and notes that certain conditions and some medications make people more sensitive. [2] This page is information only. It does not say how much anyone should have.Evidence labels used: evidence in healthy adults, mixed, insufficient evidence. Associations in observational studies are not proof of cause.
What research found
| Question | What the source found | Group and strength |
|---|---|---|
| Anxiety in healthy people | A meta-analysis of 14 studies (546 participants in eight articles) concluded that caffeine intake is associated with an elevated risk of anxiety in healthy people without psychiatric disorders. [3] | Healthy adults; the studies used different anxiety scales. [3] Mixed to limited |
| Panic disorder | In a meta-analysis of caffeine challenges, 53.9% of patients with panic disorder had panic attacks after caffeine, compared with 1.7% of healthy controls; doses were in the 400 to 750 mg range, roughly five cups of coffee. [4] | People with panic disorder; lab challenge doses, not everyday intake |
| Heart rhythm (atrial fibrillation) | A 2014 meta-analysis of six cohort studies (228,465 people) concluded it is unlikely that caffeine consumption causes or contributes to atrial fibrillation. [5] A 2018 meta-analysis also found no association. [6] | Observational studies of coffee or caffeine intake; not a test of pills or concentrated products |
| Heart disease generally | A 2024 review says controversy remains about risks, particularly in people with heart disease. [7] | Insufficient evidence for firm advice |
| Blood pressure | In 102 light users, caffeine significantly increased blood pressure. [8] A 2024 meta-analysis of energy drinks (caffeine plus other ingredients) found raised blood pressure and cardiac output in healthy adults, but not resting heart rate or QT interval. [9] | Healthy adults; short-term |
Notice what these do not show. The atrial-fibrillation studies were of usual dietary intake, so they do not tell us what happens with high-dose pills, pure powder or caffeine mixed with other stimulants. A reassuring average also does not mean a given person with a heart condition is safe. MedlinePlus says to check with a provider about limiting or avoiding caffeine if you have anxiety or an arrhythmia (a problem with heartbeat rate or rhythm). [10]
Sleep
A meta-analysis of 24 studies found caffeine reduced total sleep time by 45 minutes and sleep efficiency by 7%, and lowered the time spent in deep sleep by 11.4 minutes. [11] A 2024 review says caffeine slows sleep onset, blocks adenosine receptors and lowers deep sleep, especially in sensitive people. [12] EFSA found that single 100 mg doses may affect sleep length and patterns in some adults, particularly close to bedtime. [13] MedlinePlus says caffeine's effects can last four to six hours. [10] The NHS notes that drinks with caffeine can keep you awake. [14] Poor sleep can then worsen next-day focus and anxiety; sleep advice is in caffeine, alcohol and sleep and nootropics and sleep.Who may be more sensitive
Sources name these groups:- Panic disorder: much more likely to have panic attacks after a caffeine challenge. [4]
- Anxiety, irregular heartbeat, high blood pressure, sleep disorders, migraines or reflux: MedlinePlus says to check with a provider about limiting or avoiding caffeine. [10]
- Children and teens: the FDA says too much caffeine can cause increased heart rate, palpitations, high blood pressure, anxiety and sleep problems. [2]
- People on certain medicines: MedlinePlus lists stimulants, certain antibiotics, asthma medicines and heart medicines. [10] See caffeine and medicines.
- Genes and metabolism: a review reports caffeine kinetics vary greatly because of CYP1A2 variants and other factors. [15]
For epilepsy, heart rhythm, psychiatric and sleep conditions together, see nootropics and people with epilepsy, heart rhythm, psychiatric or sleep conditions. For anxiety itself, see anxiety disorders.
Frequently asked questions
Can caffeine cause anxiety?
A 2024 meta-analysis found caffeine intake associated with higher anxiety risk in healthy people, and people with panic disorder were far more likely to have panic attacks after a caffeine challenge. [3][4]
Does caffeine cause atrial fibrillation?
Two meta-analyses of observational studies found no increased risk from usual intake, but they did not test pills or concentrated products. [5][6]
Why do I get palpitations after caffeine?
The FDA lists palpitations as a sign of too much caffeine. [2] If it happens often, talk with a clinician.
Does caffeine hurt sleep even if I fall asleep fine?
A meta-analysis found shorter total sleep, lower sleep efficiency and less deep sleep after caffeine. [11]
Who should avoid caffeine?
MedlinePlus says to ask a provider if you are pregnant, breastfeeding, or have anxiety, an irregular heartbeat or high blood pressure. [10]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Pregnancy, surgery, kidney and liver
Pregnancy and breastfeeding are covered in caffeine in pregnancy, breastfeeding, children and teens. Liver disease is reported to affect caffeine metabolism. [15] We did not find an official page we could read on caffeine and kidney disease or caffeine before surgery, so we make no claim; ask the clinician or pharmacist managing your care.
When to see a clinician
The FDA advises talking with a health care professional about your caffeine consumption if you have symptoms such as palpitations, anxiety, jitters or insomnia. [2] Do not treat them alone. Do not stop or change a prescribed medicine on your own. Count caffeine from every product; see caffeine supplements and reading supplement labels.
References
- U.S. Food and Drug Administration (FDA), Pure and Highly Concentrated Caffeine, content current as of 6 March 2023. Read 2026-10-22.
- U.S. Food and Drug Administration (FDA), Spilling the Beans: How Much Caffeine is Too Much?, content current as of 28 August 2024. Read 2026-10-22.
- Liu C et al. Caffeine intake and anxiety: a meta-analysis. Front Psychol 2024. Read 2026-10-22.
- Klevebrant L, Frick A. Effects of caffeine on anxiety and panic attacks in patients with panic disorder: a systematic review and meta-analysis. Gen Hosp Psychiatry 2022. Read 2026-10-22.
- Cheng M et al. Caffeine intake and atrial fibrillation incidence: dose response meta-analysis of prospective cohort studies. Can J Cardiol 2014. Read 2026-10-22.
- Abdelfattah R et al. Does caffeine consumption increase the risk of new-onset atrial fibrillation? Cardiology 2018. Read 2026-10-22.
- Hamad AK. Caffeine and arrhythmias: a critical analysis of cardiovascular responses and arrhythmia susceptibility. J Saudi Heart Assoc 2024 (open-access review). Read 2026-10-22.
- Childs E, de Wit H. Subjective, behavioral, and physiological effects of acute caffeine in light, nondependent caffeine users. Psychopharmacology 2006. Read 2026-10-22.
- Gualberto PIB et al. Acute effects of energy drink consumption on cardiovascular parameters in healthy adults: a systematic review and meta-analysis of randomized clinical trials. Nutr Rev 2024. Read 2026-10-22.
- MedlinePlus (U.S. National Library of Medicine), Caffeine. The copy we read showed no review date. Read 2026-10-22.
- Gardiner C et al. The effect of caffeine on subsequent sleep: a systematic review and meta-analysis. Sleep Med Rev 2023. Read 2026-10-22.
- Bagheri Davisaraei Y et al. Coffee and sleep: benefits and risks. Prog Brain Res 2024. Read 2026-10-22.
- European Food Safety Authority (EFSA), Caffeine (topic page summarizing the 2015 scientific opinion on the safety of caffeine). The full opinion could not be downloaded (HTTP 403). Read 2026-10-22.
- NHS (UK) Every Mind Matters, Sleep. Read 2026-10-22.
- Nehlig A. Interindividual differences in caffeine metabolism and factors driving caffeine consumption. Pharmacol Rev 2018. Read 2026-10-22.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.