You may have heard the phrase “morning wood” before. Both young men and older men who have either been too embarrassed to ask or who don't have someone they feel comfortable asking are curious about why this occurs. If you, like many, have experienced having an erection when you wake up in the morning, you are probably wondering what is going on.

 The truth is, it’s a difficult predicament for those without, and with a penis, to understand. Thankfully, doctors have studied the mystery of morning wood occurring in men for some time. That's right! It's a subject that even science has spent some time studying. Here are some of the interesting facts that they have discovered along the way. 

1. It's a Normal Occurrence

All men experience the phenomenon of waking up with an erection. It's just a natural part of life. There is even a medical term for having “morning wood”. It's called Nocturnal Penile Tumescence, or NPT for short.

2. Psychological or Physiological

There have been a number of assumptions as to why men experience NPT and whether it’s a psychological (mind) or physiological (body) response. For example, a psychological response could be linked to psychosomatic illness, like having sexual anxiety. A physiological response could be from having a full bladder at night.

3. Lessens with Age

The phenomenon of NPT does become a less frequent occurrence when men hit a certain age, which is usually when men reach their 60's and 70's.

4. Brain Control

Our body and bodily functions are controlled by our brains. It is for this reason that men are able to control arousal in places, such as at work, in the gym, or even when on a date. However, that changes when we sleep because some areas of the brain shut down, including the areas that keep an eye on the penis. Normally the brain regulates penile stimulation to ensure an erection only happens when it's meant to. However, when the brain reaches a state of REM sleep, it is no longer regulating that stimulation.

5. It's Down to Testosterone

One of the reasons why NPT seems stronger in the morning is down to hormones. A man's level of testosterone tends to be at its highest levels in the early part of the day, being about 25% to 50%. As the day goes on those levels will drop.

6. Physical Stimulation

The penis is aroused by physical stimulation and touch. When the penis accidentally rubs against something during sleep it will get hard from that stimulation. So, if you (or your penis) are pressed against something or someone in your sleep, guess what happens? It becomes stimulated and gets hard.

7. It's a Form of Exercise

It's a theory that NPT is the body's way of exercising the penis, conditioning it to be able to hold blood in the area for long periods. The penis is really the only part of the body that requires blood to be trapped in it for an extended period, usually for 30 to 60 minutes in some cases and be just fine afterward. Imagine tying a tourniquet around your wrist or your foot for 30 minutes. When that tourniquet is removed you are going to have some adverse effects.

8. Multiple Erections Per Night

It isn't in the morning that a man experiences an erection. They actually have several erections throughout the night. Doctors have estimated that a man will experience up to 5 erections per night, with each episode lasting up to 30 minutes. This is totally normal as well.

9. Full Bladder

One myth about NPT is that it can be caused by having a full bladder during the night or when you wake in the morning. Research has shown that with someone who is awake, a full bladder a lead to an erection occurring. However, it still isn't clear if this can also cause NPT when one is sleeping.

10. It's a Sign of Good Health

It's actually a positive thing to have morning wood. Doctors have found that men will have an average of 3 erections per night. It's a sign that you have healthy levels of testosterone.

As you can see, having morning wood is nothing to be embarrassed about and is completely normal in healthy men of all ages.

Author Bio:

Kingsley Felix is a blogger and webmaster for Krafty Sprouts, currently works at Thegloor and Healthable.