Nocturnal penile tumescence

Nocturnal penile tumescence means that a guy's penis gets bigger (like when he has a boner) while he is sleeping. This happens to almost all boys who have gone through puberty and it's completely normal. In fact, it happens to guys of all ages, even elderly men.

While people still don't know exactly why this happens, some people think that it's just a natural part of the body's way of keeping the penis healthy. When we sleep, our body goes through a lot of changes and some of those changes might involve the penis getting bigger and harder.

There's no need to worry about nocturnal penile tumescence, it's something that happens naturally and is nothing to be ashamed of. Just remember, your body is an amazing thing that does all sorts of things while you sleep to keep you healthy!