There are seven things that men should know-- but don't-- about their sexual health.

1. Why men fall asleep after sex.
It gets really irritating when your woman wants an after-sex cuddle when all you want to do is roll over and fall into a deep slumber. Ever wondered why? According to Dr. David McKenzie, sex therapist in Vancouver, Canada, when a man reaches orgasm, his body releases the biochemical prolactin which alters his body physically making him very tired. Other than the fact that a man exerts a lot of energy during sex, especially after climaxing which leads to sleepiness. So if you want her to get off your case about sleeping after sex, you could tell her it's because you had such an amazing night with her and just maybe she'll happily let you sleep the next time.

2. Men go through libido PMS.
She may think that men are always horny (Which is partly true), but the truth is our libido goes through a series of peaks and valleys too, just like PMS for women. Testosterone levels shift according to this pattern every month affecting our libido, energy level, beard growth and sperm count. Why not keep track of your personal cycles and you'll be able to take advantage of your prime times and better cope with the sense of apathy the valleys bring.

3. The penis tells a lot about your overall health.
Believe it or not, your manhood tells you more than just when you're horny. It can also tell you when you're having arterial problems if it's not standing tall; other than ringing the warning signs of diabetes, endocrine disorders, heart and vascular problems. However, it's not necessary to start waving the red flag as it may be telling you something else-- like fatigue, psychological factors, relationship issues, poor nutrition or lack o exercise.

4. Disrupted sleep = Less erections= Low sexual health.
If you're struggling with obstructive sleep apnea (OSA) you're at risk for sexual dysfunction. OSA decreases rapid-eye-movement (REM) sleep which means fewer REM erections, affecting sexual health. If you have trouble getting it up, get tested for OSA. Men who are diagnosed and treated often see an improvement in sexual functioning.

5. Eco-friendly transportation not so friendly on testicles.
I know you want to do something for the Earth and you've switched to cycling instead of the usual short drive to work. But did you know, that cycling can cause damage to your testicles? Although it does not cause male infertility, telltale signs of testicular damage include genital numbness, erection problems and skin irritations. Although, that's no reason to giving up cycling. Just make sure that you were shorts with protective padding and adjust your seat's position so it doesn't put pressure on your groin.

6. Varicocele can cause male infertility.
If you noticed swelling on your scrotum, it may be a sign of enlarged veins which is also known as varicocele, one of the most common identifiable cause of male infertility. Other possibilities include blockage in the reproductive tract and the fact that you're aging. Keep your sperm strong by eating nutritiously, exercising regularly and decreasing your stress level.

7. Penis size doesn't really matter.
An average penis is about five inches when erected and three inches when flacid. So if you think that you need to be seven inches to perform better, you're wrong. That thought only decreases your confidence and lowers performance. During intercourse, penis size has little to do with partner satisfaction because most of the sensitive nerve endings are concentrated close to a woman's vaginal opening. Well, that certainly lifts the weight off our shoulders, doesn't it? Now all we have to do is convince her.

Seriously, these things should be talked about more often. Would've taken a lot of pressure and pain of wondering WHY?