You've heard of arachnophobia and probably know somebody who has claustrophobia, but there are loads more fears you may have never even heard of before.

How about these? There's geniophobia, podophobia and hippopotomonstrosesquipedaliophobia.

What do each of these mean? You can click through the photo gallery at the top of this story and read each caption to learn about 13 strange (but very real) phobias.

MORE | Why is Friday the 13th known as unlucky?