Trigger explorer
Understanding why palpitations happen is the first step to managing them. Explore the most common triggers below.
Notice palpitations
Feel anxious
Heart rate increases
Notice even more
The attention loop: awareness of palpitations creates anxiety, which worsens them.
Most people identify one or two main triggers. You do not need to address all of these — focus on what resonates with you.
This guide uses JavaScript for the interactive cards. Here is the same trigger information as a static list.
Caffeine (MODERATE — Europace meta-analysis)What happens: Caffeine blocks adenosine receptors and increases adrenaline release. This raises heart rate and can trigger ectopic beats (extra heartbeats). What you might notice: A fluttering or racing feeling 15–60 minutes after coffee, tea, energy drinks, or dark chocolate. What to try: Use the Caffeine Experiment to test whether caffeine is a trigger for you personally. Booklet Day 3 — Discover Your Triggers. Alcohol (HIGH — NEJM 2020 RCT)What happens: Alcohol directly irritates heart muscle cells and disrupts electrical conduction. After drinking, the withdrawal effect increases sympathetic nervous system activity. Even moderate regular drinking (10+ drinks per week) was shown in a landmark NEJM trial to significantly increase AF recurrence. Abstinence reduced the hazard of recurrence by 45% (HR 0.55, 95% CI 0.36 to 0.84; Voskoboinik et al., N Engl J Med 2020;382(1):20–28, doi:10.1056/NEJMoa1817591 ). What you might notice: Palpitations during drinking or, more commonly, the morning after. Even one or two drinks can trigger episodes in sensitive people. The pattern is often a 12–24 hour delay. What to try: Track alcohol intake in your diary. Consider a 2-week alcohol-free experiment, similar to the caffeine test. The evidence suggests that even moderate reduction helps. Record in your daily diary. Discuss at your appointment. Poor sleep (MODERATE — 14.3M participants)What happens: Sleep deprivation increases sympathetic nervous system activity and reduces heart rate variability (HRV). The UK Biobank study of 403,187 people (Li et al., J Am Coll Cardiol 2021, doi:10.1016/j.jacc.2021.07.023 ) found the same link. What you might notice: More ectopics on days after poor sleep. Feeling “wired but tired”. What to try: Complete the Sleep Scorecard and try the sleep anchor technique from Day 4. Booklet Day 4 — Sleep and Your Heart. Stress and anxiety (LOW — indirect evidence)What happens: Stress triggers the fight-or-flight response: adrenaline rises, heart rate increases, and the threshold for ectopic beats drops. Anxiety can also cause hyperventilation, which lowers CO2 and causes tingling and chest tightness. What you might notice: Palpitations during or after stressful events. The attention loop can amplify symptoms. What to try: The 4–6 breathing technique activates the parasympathetic system. Try the guided breathing exercise . Read more: Health Anxiety and Palpitations . Booklet Day 2 — Learn to Breathe. Dehydration (LOW — physiological rationale)What happens: When blood volume drops, the heart compensates by beating faster. Dehydration also disrupts electrolyte balance (sodium, potassium, magnesium), which affects electrical conduction. What you might notice: Palpitations on hot days, after exercise without drinking, or when urine is dark yellow. What to try: Aim for 1.5–2 litres of water daily. Increase in warm weather and after exercise. Booklet Day 3 — Discover Your Triggers. Large meals (LOW — physiological rationale)What happens: A large meal diverts blood to the gut and stimulates the vagus nerve via gastric distension. This can trigger ectopic beats, particularly when lying down soon after eating. What you might notice: Fluttering or missed beats within 30 minutes of a large meal, especially in the evening. What to try: Eat smaller, more frequent meals. Avoid lying down for at least 30 minutes after eating. Booklet Day 3 — Discover Your Triggers. Exercise (HIGH — Cochrane 2024)What happens: Large observational studies have found that regular moderate physical activity is associated with a significantly lower risk of atrial fibrillation. However, sudden intense exertion in an untrained person can trigger ectopics due to adrenaline surges. What you might notice: Palpitations during or just after intense bursts of activity, especially if you are not regularly active. What to try: Start with gentle walking and gradually increase. See the Move step of the self-guided booklet for a structured approach. Booklet Day 5 — Start Moving. Hormonal changes (LOW — observational)What happens: Oestrogen and progesterone fluctuations affect cardiac ion channels. Palpitations are common during periods, perimenopause, and pregnancy. Thyroid hormone excess (hyperthyroidism) is a well-known cause. What you might notice: Palpitations that follow a monthly pattern or coincide with perimenopausal symptoms (hot flushes, night sweats). What to try: Track timing against your cycle. If a hormonal pattern emerges, mention it at your appointment — it may change the approach. Booklet Day 6 — Understanding Your Results. Weight and body composition (MODERATE — LEGACY trial)What happens: Excess weight increases the volume of fat around the heart (epicardial fat), which can trigger inflammation and electrical instability. The LEGACY trial found that patients who lost 10% or more of their body weight had an 88% rate of AF reversal, compared to just 26% in those who lost less than 3%. What you might notice: If you are overweight (BMI 27+), you may notice palpitations are more frequent or more sustained. Weight-related palpitations often improve gradually over months rather than days. What to try: If your BMI is above 27, weight management could be one of the most impactful changes you make. Even a 5–10% reduction in body weight has measurable cardiac benefits. Discuss a realistic plan at your appointment. Discuss at your appointment. Dr Ahmad can assess whether weight management is relevant to your symptoms. Omega-3 fish oil supplements (IMPORTANT; HIGH — Circulation 2021)What happens: Counter-intuitively, omega-3 fish oil supplements appear to increase the risk of atrial fibrillation. A meta-analysis of 7 large randomised trials (81,210 participants) found a 25% higher rate of atrial fibrillation overall (HR 1.25, 95% CI 1.07 to 1.46), rising to 49% above 1 g/day (HR 1.49, 1.04 to 2.15) — Gencer et al., Circulation 2021, doi:10.1161/CIRCULATIONAHA.121.055654 . This does not apply to eating fish as part of your diet. What you might notice: If you are taking fish oil supplements and experiencing palpitations, the supplements themselves could be contributing. What to try: Discuss your supplement use at your appointment. If you take omega-3 supplements above 1g/day, raise it at your next appointment — and if they were prescribed, do not reduce or stop them without speaking to whoever prescribed them. Eating fish 2–3 times per week is not associated with the same risk. Mention all supplements at your appointment.
Seek urgent help: If you have chest pain, fainting, severe breathlessness, or feel acutely unwell, call 999 immediately. This is not an emergency service.