Q: Why do men have morning wood?
A: When people sleep, the body undergoes changes that are meant to help it heal. One of these changes is that all of the blood vessels in the body open up to allow for increased blood flow. This helps to deliver nutrients and take away waste from all of the cells in the body. This increase blood flow can also result in erections in men. It also tends to result in slight vaginal swelling and lubrication in women (although this is less noticeable). So, just think of morning wood as a "side effect" of your body healing itself.
You can also find a great video about this at https://youtu.be/D1et5NgT6bQ
Answers provided by Dr. Ross Avilla
Dr. Ross Avilla has been teaching Human Sexuality since 2013 and has a PhD in psychology from UC Davis. Dr. Avilla is not a clinician and all information and advice offered on this website is for educational purposes only.