There are many reasons why you may be experiencing excessive thinning of your hair.  Here is a list of some of the most common causes of thinning hair.

-Medications:  Many commonly prescribed medications can cause significant thinning of the hair.  For instance medications like lithium, diet pills with amphetamines, and chemotherapy drugs have a strong association with hair loss.  Thinning hair can also occur in women who take contraceptives.  The good news is when these drugs are discontinued the hair often recovers.

-Menopause:  Nearly 37% of women experience thinning hair after menopause.  During menopause a women does not produce as much estrogen as she used to.   The result is a net excess of testosterone leading to thinning hair on the head and unwanted hair growth in other areas.

-Child Birth:  Some women lose massive amounts of hair within three months of giving birth.  Not to worry this situation often corrects itself with time.

-Androgenetic Alopecia:  This is the most common form of thinning hair.  It is commonly referred to as male pattern baldness.  Although researchers are studying risk factors that may contribute to this condition, most of these factors remain unknown. Researchers have determined that this form of hair loss is related to hormones called androgens, particularly an androgen called dihydrotestoterone (DHT).

-Ringworm:  This fungal infection is highly contagious.  It can cause scaling of the scalp and hair loss in patches.  Topical remedies both prescription and over the counter are available to treat ringworm.

-Thyroid Disease:  There are two kinds of thyroid disease relevant to thinning hair: Hyperthyroidism, and Hypothyroidism. Both hyperthyroidism and hypothyroidism are more commonly found in women.  Hyperthyroidism is a condition that overly produces thyroid hormone by an enlarged thyroid gland, which causes hair loss.  Hypothyroidism is a condition where the thyroid gland does not product enough hormone.  This problem can be controlled by prescription medication.  Your doctor will conduct blood work and other test to determine if you suffer from a thyroid condition.

-Genetics:  If your mom or dad experienced thinning hair then you are at an increased risk.  Recent research studies indicate the maternal bloodline carries the highest risk for male pattern baldness.  You cannot do anything about your genes, but there are breakthrough treatments that cannot only slow thinning hair, but also help re grow hair.