Call 999/911 IfFainting during exercise, fainting with no warning, fainting with chest pain or palpitations, or if the patient doesn't wake up fully within 60 seconds.
Types of Syncope
| Type | Trigger | Warning Signs | Duration |
|---|---|---|---|
| Vasovagal | Pain, emotion, prolonged standing | Nausea, pallor, sweating | Seconds; full recovery |
| Orthostatic hypotension | Standing quickly | Lightheadedness on rising | Brief; position-dependent |
| Cardiac arrhythmia | Often none | Palpitations may precede | Variable; potentially fatal |
| Structural cardiac | Exertion (valvular disease) | Chest pain, breathlessness | During or after exercise |
| Epilepsy (not true syncope) | Variable | Jerking, tongue bite, confusion | Prolonged post-ictal phase |
After a FaintLie flat and raise legs to restore brain blood flow. Do not sit up too quickly. Drink fluids. If the person doesn't recover normally within 60 seconds, call emergency services.
What is vasovagal syncope?
The most common faint — a reflex response to triggers like pain, blood, or prolonged standing. The vagus nerve slows the heart and drops blood pressure briefly, causing loss of consciousness.
When is fainting a cardiac emergency?
Syncope during exercise, without any warning, or associated with palpitations or chest pain raises concern for cardiac arrhythmia or structural heart disease — seek urgent investigation.
What tests are done after fainting?
ECG (mandatory), lying and standing blood pressure, FBC, glucose, electrolytes. If cardiac cause suspected: Holter monitor (24–48 hour ECG), echocardiogram, or tilt-table test.
Can dehydration cause fainting?
Yes. Low blood volume reduces venous return to the heart, triggering vasovagal or orthostatic syncope. Maintaining good hydration reduces risk.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.