'It's where you're balding that counts': What your hairline can reveal about your health | BBC Science Focus Magazine

There are few things more common, or more quietly dreaded, than a receding hairline. Up to 80 per cent of men experience some degree of male pattern baldness over their lifetimes.

It’s so normal that we barely count it as a medical event at all – just one of the standard-issue indignities of getting older, filed somewhere between reading glasses and a dodgy knee.

For the majority of men, going bald is simply cosmetic and no cause for alarm. Plenty of bald men are in rude health and will stay that way. But over the past decade or so, researchers have noticed something faintly unsettling.

Baldness – or, more precisely, male pattern baldness – keeps turning up alongside conditions that have nothing to do with your scalp. Heart disease. Insulin resistance. An enlarged or cancerous prostate.

The hair on your head, it seems, may be less of a private cosmetic matter and more of a readout on what is happening beneath the skin.