Ever wonder why... some people have an ‘innie’ belly button?

When we are born, the umbilical cord is cut and the small ‘stump’ left behind falls off after a few weeks. It leaves behind a large scar that is the belly button.

Whether you have an ‘innie’ or an ‘outie’ belly button has nothing to do with the handiwork of the person who cuts the cord, say doctors at Massachusetts General Hospital in Boston.

In fact, ‘outies’ are rare – only about ten per cent of people have them.

In most instances, it is simply extra scar tissue from the part of the umbilical cord left behind. But some are the result of a medical condition called an umbilical hernia.

At birth, there is space between the skin and the abdominal wall. If the muscles in the stomach do not fuse properly after the cord stump falls off, an umbilical hernia can form.

Most of hernias heal within a year, but the ‘outie’ may remain.