A woman suffered a stroke while receiving oral sex from her lover. The 44-year-old, from west London, was "nearing orgasm " when she passed out in the bedroom.
She was rushed to hospital where doctors found a blood vessel had burst inside her skull.
Medics at West Middlesex University Hospital in Isleworth, west London, said the patient was unconscious for three minutes after first suffering a headache during oral sex.
And her partner, whose gender is unknown, said they noticed "her body was stiff".
"On closer history taking, the patient reported nearing orgasm while receiving oral sex from her partner before losing consciousness," doctors this week wrote in the British Medical Journal .
"She had been otherwise well preceding the event." The woman spent two weeks in hospital recovering in October 2018.
Medics initially thought she had suffered a seizure but CT scans revealed there was blood between her skull and her brain, showing she had actually had a stroke.
They diagnosed a subarachnoid haemorrhage – an uncommon type of bleeding on the brain – but said it was only "small in size".
In the report, the doctors acknowledged that sexual activity has been "well-described" as a cause of blood vessels bursting because it increases blood pressure .
They wrote: "Older studies with [artery] monitoring during coitus demonstrate that during sexual activity blood pressure, as well as heart rate, is very [liable to change], with particular rises during orgasm."
The woman was revealed to be a regular smoker, occasional drinker, asthmatic and had suffered malaria in her brain in her 20s, but these were not directly linked to her stroke in the report.