Home > Mental health > News Updated 13 December 2013 Laughter can be dangerous to some people Laughter may not be the best medicine after all and can even be harmful to some patients. 0 iStock Related Laughing yoga cultivates merry mindfulness Teaching the brain to process laughter Animals on a trampoline Ask CyberShrink » Talk Heart to heart forum » 13 hidden signs of stress Regenerative medicine: replacing brain cells lost from stroke Researchers from Birmingham and Oxford, in the UK, reviewed the reported benefits and harms of laughter. They used data published between 1946 and 2013. They concluded that laughter is a serious matter.They identified benefits from laughter; harms from laughter; and conditions causing pathological laughter.Some conditions benefit from 'unintentional' (Duchenne) laughter. Laughter can increase pain thresholds although hospital clowns had no impact on distress in children undergoing minor surgery (even though they were in stitches). Laughter reduces arterial wall stiffness, which the researchers suggest may relieve tension. And it lowered the risk of heart attack, so "reading the Christmas BMJ could add years to your life".Clowns improved lung function in patients with COPD and 'genuine laughter' for a whole day could burn 2000 calories and lower the blood sugar in diabetics. Laughter also enhanced fertility: 36% of would-be mothers who were entertained by a clown after IVF and embryo transfer became pregnant compared with 20% in the control group.Adverse effects of laughterHowever, laughter can also have adverse effects. One woman with racing heart syndrome collapsed and died after a period of intense laughter and laughing 'fit to burst' was found to cause possible heart rupture or a torn gullet. A quick intake of breath during laughing can cause inhalation of foreign bodies and can provoke an asthma attack. Laughing like a drain can cause incontinence. And hernias can occur after laughing: rapture causing rupture.The authors' list conditions that cause pathological laughter and this may help in diagnosis. Epileptic seizures ("gelastic seizures") are the most common cause.The researchers say that their review challenges the view that laughter can only be beneficial but do add that humour in any form carries a "low risk of harm and may be beneficial". They conclude that it remains to be seen whether "sick jokes make you ill, dry wit causes dehydration or jokes in bad taste [cause] dysgeusia (distortion of sense of taste)". EurekAlert More in Mental health Weaker beer may solve a lot of problems More: Mental healthNews advertisement Read Health24’s Comments Policy Comment on this story 0 comments Comments have been closed for this article. Logout Comment 0 characters remaining Share on Facebook Loading comments... Other news Partner Content The lighter side of dinner Medical Adult-onset asthma linked to heart and stroke risk Medical Zika may persist for months in newborns Medical Stress may have greater effect on younger women's hearts Parenting Is mental illness linked to childhood head injuries? Parenting What is causing my baby's colic and what can I do? From our sponsors Otrivin Menthol relieves sinus congestion Innovative hearing aids can now interact online Second Healthcare Innovation Summit set for Johannesburg Salomon introduces Speedcross 4 Live healthier Nutrition crisis! » Good nutrition on the job will give you the edge Nutrition labels on food encourage healthy choices Nutrition may be as big a challenge today as HIV/Aids was 15 years ago Many people in a large number of low and middle income countries now experience a 'double burden' of malnutrition. E-cigarettes less risky? » E-cigarettes not an acceptable alternative to most smokers UK health officials endorse e-cigarettes E-cigarettes less of a cancer risk than regular smokes A study indicates that smokers who switch to e-cigarettes reduce their exposure to cancer-causing chemicals.