Waking with a pounding or racing heart has several possible explanations. Stress, stimulants, sleep-related breathing problems and an intermittent heart rhythm disturbance can produce similar sensations. The fact that an episode happens at night does not establish its cause.
In Sweden, call 112 if palpitations occur with chest pain, severe difficulty breathing or fainting. Persistent, intense palpitations also need prompt assessment. Do not wait for a routine online appointment when you feel seriously unwell.
Describe the rhythm, not just the feeling
“My heart was pounding” can mean a forceful but steady beat, a rapid regular rhythm, or irregular beats and pauses. Describe whether the episode started suddenly, how long it lasted and whether it stopped abruptly. These details help a clinician decide which questions and tests are useful.
If you otherwise feel well, a brief pulse check at your wrist can help you describe the episode. Record whether it feels regular and its approximate rate if you can measure it comfortably. Avoid repeatedly checking throughout the night. A watch alert or a pulse number is information to discuss, rather than a diagnosis.
What might explain nighttime palpitations?
- Waking and stress: your body may feel activated after an awakening. Anxiety may also follow a frightening episode, so its presence does not settle the cause.
- Caffeine, alcohol or nicotine: the timing and amount may be relevant. A suspected trigger does not rule out a rhythm problem.
- Sleep apnoea: mention loud snoring, witnessed breathing pauses and daytime sleepiness. Palpitations alone cannot diagnose sleep apnoea.
- A rhythm disturbance or another medical problem: the assessment may include medicines, heart history and selected blood tests where the symptoms suggest a reason.
A short night diary to bring to your appointment
Use one row per episode. You do not need to collect perfect data before seeking help, and recording an episode must never delay urgent care.
| Record | Example or prompt |
|---|---|
| Time and duration | When did you wake, and approximately when did it settle? |
| Rhythm and onset | Steady racing, irregular beats or isolated thumps? Sudden or gradual? |
| Other symptoms | Chest discomfort, breathlessness, dizziness or fainting? |
| Context | Evening drinks, a new medicine, snoring or a witnessed breathing pause? |
For example, “02:15, steady fast pulse for about five minutes, no chest pain, wine earlier in the evening” describes a sequence. It does not prove that the wine caused it. Keep observations separate from conclusions when you discuss the diary.
What can an ECG show?
A standard ECG records a short period of heart activity. An intermittent problem may not be present during the appointment, so a normal recording does not necessarily explain a previous episode. Depending on the pattern, a clinician may consider longer monitoring. A sleep-apnoea investigation measures breathing during sleep and answers a different question.
Ask what the proposed test could change, whether you need to record symptoms while using it, and how you will receive the result. A single investigation does not answer every possible cause of palpitations.
Where to seek help in Sweden
Contact a vårdcentral, a primary care centre, for recurrent or changing episodes. Describe any known heart disease and provide your medicine list. Call 1177 for advice about the appropriate level of care if you are unsure. Ask your chosen provider whether an in-person examination or monitoring is available and what any private fees cover.
Common questions
Does waking with palpitations mean I have anxiety?
No. Anxiety is one possibility, but the timing alone cannot distinguish it from other causes. Recurrent symptoms deserve an assessment.
Should I stop a heart medicine if I suspect it is involved?
Do not change prescribed treatment on your own. Tell the prescriber what happened and seek urgent help if the symptoms are severe.
Sources and further reading
- 1177: Hjärtklappning (in Swedish)
- Läkemedelsboken: Hjärtrytmrubbningar – bakgrund (in Swedish)
- 1177: Obstruktiv sömnapné (in Swedish)
Sources and links checked on 22 October 2026. Editorial team: Hagakliniken. This is general information and does not replace an individual medical assessment.