Most hair loss is genetically inherited and not a result of external factors. In fact, 95 percent of hair loss in men older than 40 is a genetic condition called androgenic alopecia or, in plain English, “pattern hair loss”. Because of your genetic makeup your body converts too much testosterone into another hormone called dihydrotestosterone (DHT). One of the places where this conversion happens is the hair follicles on your scalp. Too much DHT production causes hair follicles to shrink (miniaturize). The follicles then shed existing hair and won’t regrow new hair.
This process starts at the hairline right above the forehead and proceeds in a V-shaped pattern, with the temples going bald first. Eventually, after many years the entire head will be bald. Some 50 percent of men get it sooner or later at one point in their lives. For Caucasians, it’s even 80 percent. There also is female pattern hair loss, but it’s typically only observed in elderly women and very rarely leads to complete baldness.
Beyond androgenic alopecia, there are some rarer forms of baldness, such as autoimmune disorders or hair loss caused by malnutrition, prolonged sickness or exposure to certain chemicals and medications.
Talk to a dermatologist to learn more about androgenic alopecia and the other types of hair loss. A dermatologist can also recommend you effective treatments for androgenic alopecia, such as finasteride, which has a proven success record of stopping baldness and spurring hair regrowth.
Several factors can exacerbate already ongoing androgenic alopecia, even though they in themselves don’t trigger hair loss. Stress is a common culprit here, especially chronic long-term stress which constantly keeps the body’s cortisol (the stress hormone) levels elevated. Cortisol interrupts the normal regeneration cycle of your hair, causing premature shedding of hair and slowing new growth. Stress thus can speed up existing male pattern baldness.
Another condition that may worsen male pattern hair loss is dandruff, as it often is accompanied with an itchy scalp and the resultant urge to scratch your head. Such scratching can further hurt already damaged hair follicles and hair falls out faster.
Stress and itchy dandruff are the two most common factors that can worsen pattern hair loss. So, what about hats?
You’ll be fine unless you do wear a tight latex swim cap or medieval knight helmet around the clock every day throughout the year. And if you do, hair loss should be the least of your worries.
It doesn’t even have to be a helmet fetish. A tight hat worn for several hours of the day, especially during hot and/or humid weather, can irritate the scalp which may lead to itchiness. The itchier the scalp gets, the more you’ll scratch your head (during the times you don’t don a hat). As discussed in the section above, this scratching can exacerbate pattern hair loss.
Moreover, malassezia, a fungus which can cause dandruff, loves warm and dark places and may thrive under your hat. Generally, if you are a regular hat wearer, it’s a good idea to maintain proper scalp hygiene and frequently wash your hat. As long as you do that, no harm will come to you from wearing a hat.