In most cases palpitations at night are noticed because the room is quiet, you are still and there is not much else going on. Lying on your left side brings the heart closer to the chest wall, so you feel a normal or slightly irregular heartbeat more clearly. Noticing an unusual heartbeat can cause anxiety, which in turn increases adrenaline and your heart rate.
Common causes at night
- extra (ectopic) beats, which are often more noticeable when your heart rate slows at rest
- caffeine or alcohol earlier in the evening, or a large late meal
- stress, worry or a busy mind as you try to sleep
- waking from a vivid dream or nightmare, which can make the heart race
- acid reflux, which can trigger a fluttering sensation
Less common causes worth checking
- atrial fibrillation (AF), which can start at night, particularly in people with sleep apnoea or who have drunk alcohol
- SVT, a fast regular rhythm that starts and stops suddenly
- an overactive thyroid, anaemia, or side effects of medicines
- sleep apnoea: loud snoring, pauses in breathing and daytime sleepiness are clues
What helps
Cut down on caffeine after midday and alcohol in the evening, avoid large late meals, and try lying on your right side or back. If you wake with palpitations, sit up, breathe slowly and check your pulse (see our preparation guide).
When to get checked
Book an assessment if palpitations at night are new, frequent, last more than a few minutes, feel fast and irregular, or wake you regularly. Snoring with pauses in breathing is worth mentioning, as treating sleep apnoea can reduce AF.
Call 999 if palpitations come with chest pain, severe breathlessness, fainting or nearly fainting. For urgent advice, call NHS 111.
Medically reviewed by Dr Aftab Gill, Consultant Interventional Cardiologist (GMC 4499826). Last reviewed October 2026. This page gives general information and is not a substitute for personal medical advice.