Updated August 06, 2015.

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

A stroke is a sudden and serious life-threatening event. We know that a stroke may be caused by heart irregularities, high blood pressure, stress and a number of other well-known risk factors. People have questioned for years whether sex can cause a stroke. To answer that common question, there have been several scientific research studies that have evaluated whether sexual activity can cause a stroke and who is at risk.

 

Sex as a Stroke Trigger

Overall, it is quite unusual for someone to experience a stroke during sexual activity. In fact, it is rare for a stroke to be provoked by any trigger in general. The vast majority of the time, a stroke is the result of a build up of long-term health problems such as smoking, high blood pressure, elevated fat and cholesterol levels, poorly controlled diabetes, blood clotting abnormalities and heart disease.

However, it has been documented in the medical literature that a stroke during or within 2 hours after sex is more likely to occur in extramarital relationships. It has also been noted that extramarital sexual activity increases the risk of stroke related death. Whether this is due to the  increased stroke rate associated with extramarital sexual activity or to a reluctance to call for urgent medical attention is not clear.

 

How Often Does a Stroke Occur During Sexual Activity?

It is probably impossible to obtain entirely accurate data about this question. In general, people are less likely to declare that a stroke occurred during sex than they would report that a stroke occurred while doing another, less private activity, such as driving or jogging.

A recent scientific article published in the February 2015 issue of the Journal of Stroke and Cerebrovascular Disease evaluated 290 patients who were diagnosed with stroke and reported that only 5 of the patients specified sexual activity as a triggering event. This relatively low number is consistent with the previous research on the triggering events associated with stroke.

 

Who is at Risk?

People who experience a stroke during or within a few hours of sexual activity generally experience warning signs weeks or even months ahead of time. One of the most common warning signs is a thunderclap headache. A thunderclap headache is a sudden, severe explosive, excruciating headache.

If you ever experience a thunderclap headache, or any variation of a severe headache during sexual activity, you need to call your doctor, who will perform a thorough medical evaluation. Some people who experience a thunderclap headache during sex do not go on to suffer from a stroke, but about 30-50% are at risk of having an ischemic stroke. 

Sexual activity is also risk factor for those who have a brain aneurysm and thus may trigger a hemorrhagic stroke.

It does not appear that older age is necessarily a risk factor for a stroke caused by sex. It has been reported that young people, who do not have the typical stroke risk factors, have been among those who experience a stroke during sexual intercourse. Blood clotting disorders, serious inborn heart defects, brain aneurysms or drug use seem to play a role in these rare situations.

 

What Should You Do?

If you ever experience headaches, dizziness or any neurological symptoms during or after sexual activity, you should have a medical evaluation right away. If your partner has symptoms such as headaches, dizziness, vision changes, slurred speech, weakness or confusion during or after sexual activity, it is vital for you to make sure your partner receives urgent medical attention right away. Ischemic stroke and hemorrhagic stroke, both of which can happen infrequently during sexual intercourse, are serious and sometimes fatal events.

Sources:

Sexual activity with and without the use of sildenafil: risk of cardiovascular events in patients with heart disease, Alboni P, Bettiol K, Fucà G, Pacchioni F, Scarfò S, Italian Heart Journal, May 2004

Prevalence of Triggering Factors in Acute Stroke: Hospital-based Observational Cross-sectional Study, Sharma A, Prasad K, Padma MV, Tripathi M, Bhatia R, Singh MB, Sharma A, Journal of Stroke and Cerebrovascular Disease, February 2015

Ischaemic stroke provoked by sexual intercourse, Calabrò RS, Pezzini A, Casella C, Bramanti P, Triolo O, Journal of Clinical Neuroscience, September 2013

Trigger factors and their attributable risk for rupture of intracranial aneurysms: a case-crossover study, Vlak MH, Rinkel GJ, Greebe P, van der Bom JG, Algra A, Stroke, July 2011

Thunderclap headache attributed to reversible cerebral vasoconstriction: view and review, Valença MM, Andrade-Valença LP, Bordini CA, Speciali JG, The Journal of Headache and Pain, October 2008