The number one cause of excessive hair growth is heredity and ethnic background. Superfluous or excessive hair growth is often a result of normal biological changes that women undergo throughout life, such as puberty, pregnancy, menopause and old age. These are the main life changes that can effect hormone fluctuations in the body. Any one of these changes may cause an increase in hair growth in areas that never had hair before, or cause a small to moderate problem area to worsen. Other causes of hair growth can be associated with certain medications, stress and obesity. More seriously, it the cause can be an abnormality in the endocrine system such as irregular menstrual cycles, ovarian disorders; such as Polycystic Ovarian Syndrome (PCOS), and thyroid abnormalities.