Man's Dipstick - Your penis is a barometer of overall health

Dr. Mehmet Oz, co-author of You: The Owner’s Manual, calls it your “dipstick” because it reveals the health of your other body parts. The physical mechanisms that send blood to your brain, heart and kidneys also inflate your penis. If it’s not standing tall, you may have arterial problems. “A man’s lack of interest in sex is a big red flag that something is out of balance. Up to 25% of men have a low-to-no sex drive,” says Dr. Laux. “It could be even higher, as men don't talk about low libido.” The possible causes of restricted blood flow include diabetes, endocrine disorders, heart and vascular problems or kidney diseases. “But,” says Laux, “don't rule out fatigue, psychological factors, relationship issues, poor nutrition, insomnia or lack of exercise.”

Men fall asleep after aex
A man’s body chemistry changes after orgasm. The biochemical prolactin is released, physically altering his body and making him very tired. Further, exertion during sex and after climax depletes the muscles of energy-producing glycogen, which leads to sleepiness. Since men have more muscle mass than women, they’re generally sleepier after sex.