Telogen effluvium is the most common form of diffuse hair loss .  It  results in loss of more than 200 scalp hairs per day. It typically develops after an acute event, such as a severe illness, major surgery, thyroid disease, pregnancy, iron-deficiency anemia, malnutrition or rapid weight loss.  Vitamin D deficiency can also contribute. In other cases diffuse thinning can simply be a result of aging.  Diffuse hair loss due to aging is hard to combat and in most cases is permanent.   However, if your diffuse thinning is caused by hormonal or dietary factors, then it may be reversible.   Drugs can cause diffuse hair loss that starts about 12 weeks after starting the drug and continues while on the drug.   Any medication or over-the-counter product the patient is taking should be suspected in hair loss.   Many cases depending on age and health can come back from this condition.    Others need help along the lines of HRC’s extreme growth therapy or similar  restart programs.   Diffuse hair loss mostly occurs in women whereas men primarily are plagued with male pattern baldness and generally can not be treated with diet improvements and the absence of a required prescription drug.   Given the complexity of the diagnosis of diffuse hair loss, a clinical examination is of great importance. The scalp should be examined for the degree and pattern of hair loss.  If you feel you are suffering from diffuse hair loss your first step would be getting a scalp analysis at a clinic.   From there assessments can be made and possible  and a course of action can be discussed.