Like so many things, it comes down to a mixture of genetics and hormones. We know that at least some of the genes for hairiness are carried on the X chromosome – and the way these genes are expressed varies between different men and ethnic groups – but hairiness also correlates with high testosterone levels.
Testosterone is the most potent of the male hormones. Testosterone stimulates hair growth on the face and body. Generally, the more testosterone, the faster and coarser body and facial and body hair will grow. Beginning at puberty, and often accelerating during the 20's, total body hair increases in men.
If you have high testosterone, you will likely have high levels of dihydrotestosterone (DHT). This is a hormone that's stronger and more potent than testosterone. When the body has high levels of DHT, it will grow more facial and body hair.
Testosterone promotes body hair growth in men. As a result, one common symptom of low testosterone is a loss of body hair.
Men develop more androgenic hair than women because we have more androgens. Androgens (sometimes referred to as male sex hormones because we more of them than women) are sexual hormones such as testosterone, androstenedione and DHT, which create male characteristics. This, of course, includes being hairier.
The main purpose of body hair is to help regulate our temperature in addition to keeping dirt out of our body (in areas such as our eyes and nostrils).
PROTECTION AGAINST THE SUN: People who have a hairy body are less prone to sunburn and rashes. Another purpose that they serve is to keep us warm. This process goes like this- when we feel cold, our body hair stands on end and trap warm air which is closer to the surface of the skin.
Scientists think that the build-up from years of producing testosterone disrupts the cycle of hair growth in men. As a result, the hair in some places grows longer before it falls out. That's why older men need to keep trimming eyebrows, nose hair and ear hair!
Men with high testosterone can experience a variety of troubling symptoms and possible health consequences. Excess testosterone can lead to more aggressive and irritable behavior, more acne and oily skin, even worse sleep apnea (if you already have it), and an increase in muscle mass.
Since testosterone is an androgen, it can help with hair growth. Though, it leads to the growth of body and facial hair. Sadly, it doesn't improve hair growth where we need the most – on our head. In fact, its excessive amount in our body can lead to hair loss on the scalp.
Are men with thicker hair more virile? This is another myth. Men with thinner hair and bald men are not less virile than their hairy peer. High free testosterone and total testosterone in the blood are associated with greater virility and also with baldness.
Excess facial or body hair is often a symptom of an underlying medical problem. See your doctor for assessment if over a few months you experience severe or rapid hair growth on your face or body or signs of virilization.
As we age, our prolonged exposure to testosterone starts to play a visible role on other body hair as well. Just like it transforms the vellus hair on a young man's face into a thick beard, it also changes the nearly invisible hair that grows in places like our ears into thicker strands.
Bald men are no more virile and they don't have higher testosterone levels, though they do tend to have hairier arms, legs and chests. Perhaps most surprisingly, bald men don't actually have any fewer hairs on their heads.
Summary: Hair samples from teens could help detect their risk of mental health problems. Researchers found teens with higher cortisol levels in hair samples were more likely to experience depression. Low cortisol levels were also linked to an increased risk of mental health issues.
The short answer is there isn't a proven link between orgasms and testosterone levels, so we don't know how it affects you in the short term. However, you can take comfort in knowing that masturbating will not negatively affect your testosterone levels—or other aspects of your life—long-term.
While testosterone definitely plays a role in your sexual function, many men with low levels of testosterone (also referred to as low-T or hypogonadism) can get erections just fine.
Like so many things, it comes down to a mixture of genetics and hormones. We know that at least some of the genes for hairiness are carried on the X chromosome – and the way these genes are expressed varies between different men and ethnic groups – but hairiness also correlates with high testosterone levels.
As you age and your testosterone decreases, usually in your 50s, you'll start to notice things are a little less bushy down there. “It's a slow progressive loss,” Steixner explains.
Genetics is the most common cause of a hairy back in men. Certain genes in men make them more likely to be susceptible to the effects of testosterone, which encourages the growth of body hair. This is also why most men grow facial hair more easily than most women.
A Hairy Chest Might Mean You're More Intelligent
The hairier the chest, the smarter the man, at least according to one survey that found nearly 50% of medical students were considered “very hairy” compared to 10% of the general population. (We'd love to know exactly how they surveyed this, but data is data.)
The individual occurrence and characteristics of chest hair depend on the genetic disposition, the hormonal status and the age of the person. The genes primarily determine the amount, patterns and thickness of chest hair. Some men are very hairy, while others have no chest hair at all.