ERECTIONS_sandbox

When the penis becomes hard and enlarged, this is called an erection.

It’s caused by decreased blood flow out of the penis. Despite the nickname for an erection, there is no bone in the penis!

Erections can occur WHEN…

  • A person experiences sexual arousal
  • Parts of the body including the penis are touched.
  • For no reason at all – this is called an involuntary or spontaneous erection.

Erections can last anywhere from a few minutes to a few hours. If an erection lasts longer than 4 hours, it’s important to seek medical care.

If you have an extra 2 minutes, watch this video from ASAP Science to learn about nocturnal penile tumescence (aka “morning wood”).