It is convention 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 vegetation cycle. At any given time 10% of our hair is in what is called a 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 decline. Its a normal part of the aging summons. Called Androgenetic Alopecia it accounts for 95% of all hair decline. Androgentic Alopecia much 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 retiring hair line and baldness on the top of head. Women on the other hand never go entirely bald even if their hair transferred property is severe. Instead haircloth loss is spread out evenly over their entire scalp.
Hormones play the dominant role when talking about androgenous Alopecia. simple put both men and women produce testosterone. Testosterone can be converted to dihydrotestosterone (DHT) with the assistance of the enzyme 5-alpha-reductase. DHT shrinks hair follicles causing the membranes in the scalp to thicken become inelastic and restrain blood flow. This causes the hair follicles to atrophy. As a solution when a hair does fall out it is not replaced.
While Androgenetic Alopecia is the number one cause why individuals experience hair loss it is not the only one. Medical conditions such as hypothyroidism ringworm and fungal infections can cause body covering loss. Certain medications such as blood thinners gouty arthritis 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 causal agent 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 stress on the hair and scalp. Wearing pigtails cornrows or compressed 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 excitement to the hair follicles which can also result in scarring and hair loss.