THE HAIRGROWTH CYCLE
We are all born with about 100,000 hair follicles which start as single follicles. On the average human head there is approximately 2,200 strands of hair per square inch. As you age, the single follicles then double and triple creating the hair's thickness and fullness. Over time the follicle reverses back to single a follicle. The thickness changes and the amount of hair growth decreases. Hair thickness directly correlates to the size of the hair follicles which varies for each individual. On average the thickness of each strand is about .10 millimeters. The growth cycle never stops it changes depending on what the body is experiencing.
THE ANAGEN PHASE
Longevity: Three to five years
Details: The first phase of the hair growth cycle, this is when the hair physically grows out from the follicle. A hair can grow up to 30 inches in the anagen phase.
THE CATAGEN PHASE
Longevity: 10 days
Details: This second phase is phase is actually a transitional period where the hair stops growing as it prepares to falls out shortly.
THE TELOGEN PHASE
Longevity: Three months
Details: The final part of the growth cycle, this is when the hair falls out from the follicle and rests before the growth cycle begins again.
Any type of emotional or physical stress can send your hair into a temporary state of disarray. When your body is stressed an uneven number of hairs transfer into the resting phase all at once. Then when those hairs fall out, more than normal amounts are shed.
VITMAIN OR NUTRIENT DEFICIENCY
Whereas too much Vitamin A can affect how your hair grows, not enough vitamins, especially Vitamin B can cause it to thin. The same goes for iron, which is an important factor for hair growth. An iron deficiency can slow down your hair's normal growth pattern. (Crash dieting has the same effect.) The easiest way to combat it: Take multivitamin daily.
MEDICAL CONDITION AND AUTOIMMUNE DISORDER
When the immune system has to work overtime to keep symptoms of certain diseases at bay, the body may not be able to sort out what's going on and mistake hair as something foreign and harmful to their body. Low thyroid levels can lead to hair loss. Hair thinning and hair loss caused by autoimmune disorders, also known as Alopecia Areata are more difficult to treat.
SUDDEN WEIGHT LOSS
Dropping a serious amount of weight extremely fast can cause trama to your hair, leaving it thin and weak. Its not the weight loss itself that causes it, but rather the lack of vitamins and nutrients and healthy fats that you may be depriving yourself of that change the texture of your hair.