If you're suffering from a headache, retiring to the bedroom may be the best solution.
Sex can cure head pain, according to scientists - and venturing between the sheets may even be more effective than heading to the medicine cabinet.
More than half of migraine sufferers who had sex during an attack experienced an improvement in symptoms, the researchers found, and one in five was left without any pain at all.
One theory is that sex works by triggering the release of endorphins, the body's natural painkillers, which act on the central nervous system to reduce or eliminate the headache.
"Our results show that sexual activity during a migraine attack might relieve or even stop an attack in some cases, and that sexual activity in the presence of headache is not an unusual behaviour," the researchers said.
"Sex can abort migraine and cluster headache attacks, and sexual activity is used by some patients as acute headache treatment."
It has long been thought that sex can trigger headaches. But in the new study, reported in Cephalalgia, the journal of the International Headache Society, a team of neurologists investigated whether there was any substance to anecdotal accounts that it could actually ease symptoms of migraine and cluster, or one-sided, headaches.
In the study at the University of Munster in Germany, neurologists collected data on 400 patients with the two types of headache who had been treated over a two-year period. They found that 33 per cent had made love during a headache. Of those, 60 per cent of migraine patients and 36 per cent of men and women with cluster headaches had an improvement in symptoms.
Men were more likely to benefit than women, with 36 per cent using sexual activity as a therapy for dealing with their headache. Meanwhile, 13 per cent of women used sex to combat a headache. Of the migraine patients who saw an improvement in their pain, 19 per cent had complete relief of headache symptoms, 51 per cent experienced moderate relief and 29 per cent reported mild relief.
"In total, 42.7 per cent of all migraine patients experienced at least 50 per cent relief, a response rate as high as in studies on acute medication," said the researchers.
Consultant neurologist Dr Nick Silver, of the NHS Walton Centre for Neuroscience and Neurosurgery in Liverpool, said: "This is a preliminary study, limiting conclusions that can be reached.
"We can now say, however, that the excuse of 'not tonight, I have a headache' may not be taken seriously by all sexual partners."
Researchers say there are a number of possible explanations for the findings, including the release of painkilling endorphins during sex and changes in blood pressure that occur.
Scans have also shown that the hypothalamus region of the brain is active during a cluster headache, and the same area shows activity during orgasm.
- DAILY MAIL