It is normal to shed hair every day and the truth is we loose between 100-125 hairs on any given day. Hair that is shed falls out at the end of growth cycle. At any given time 10% of our hair is in what is called a “resting phase” and after 2-3 months resting, hair falls out and new hair grows in its place. Some people, however, experience more hair loss than is normal.
As we get older, both men and women experience some hair loss. It’s a normal part of the aging process. Called Androgenetic Alopecia, it accounts for 95% of all hair loss. Androgentic Alopecia often runs in families and affects some people more than others. In men it is often referred to as Male Pattern Baldness.
It is characterized by a receding hair line and baldness on the top of head. Women, on the other hand, don’t go entirely bald even if their hair loss is severe. Instead, hair loss is spread out evenly over their entire scalp.
Hormones play the dominant role when talking about Androgenetic Alopecia. Simple put, both men and women produce testosterone. Testosterone can be converted to dihydrotestosterone (DHT) with the aid of the enzyme 5-alpha-reductase. DHT shrinks hair follicles causing the membranes in the scalp to thicken, become inelastic and restrict blood flow. This causes the hair follicles to atrophy. As a result, when a hair does fall out, it is not replaced.
Needless to say, men produce more testosterone than women and experience more hair loss.
While Androgenetic Alopecia is the number one reason why individuals experience hair loss, it is not the only one. Medical conditions such as hypothyroidism, ringworm and fungal infections can cause hair loss. Certain medications such as blood thinners, gout medication, birth control pills and too much vitamin A can cause sudden or abnormal hair loss as can following a crash diet, sudden hormonal changes, chemotherapy and radiation.
Emotional stress, pregnancy, or surgery can also cause our hair to fall out and is usually not noticed until 3-4 months after the stressful event has taken place. Stress can cause a slowing of new hair growth because a larger number of hair follicles enter into the resting phase and no new hair growth is experienced.
Another way in which individuals experience hair loss is due to mechanical stressors on the hair and scalp. Wearing pigtails, cornrows or tight rollers that end up pulling on the hair can scar the scalp and cause permanent hair loss. Hair products such as hot oil treatments and chemicals used for permanents can cause inflammation to the hair follicles which can also result in scarring and hair loss.
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