Grumpy Man Syndrome is actually something science has already explained. Research from the Mayo Clinic shows that declining testosterone levels in men as they age lead to grumpy moods.
"Testosterone is a hormone that helps muscle growth, reduces body fat, affects energy and improves sex drive," Ridwan Shabsigh, head of the International Society for Men's Health, explained to NBC. "However, it also has neuropsychological effects. In some men we encounter in our practice, this is mostly reflected in the form of bad mood and irritability."
Diabetes and kidney disease can also lead to a grumpy mood. But there is good news: Testosterone levels start to decline only after men reach the age of 60. There is no excuse for your boyfriend to be grumpy right now, reports Cosmopolitan.
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