hair loss:
Causes of Hair Loss

Permanent
Disease: such as Lupus/Diabetes Age or Heredity: Hair thinning or loss is a common sign of aging, however if someone in your family suffers from hair loss the odds of you developing the same condition increases.

Usually Temporary
Hormonal Imbalances: Over/Underactive Thyroid or changes in the androgen or estrogen levels.

Side effect of Medication: Medicine for High Blood Pressure, Heart conditions, Birth Control and Depression can cause hair loss. As well as Radiation and Chemotherapy. Fungal infections. Side effect of excess stress or surgery.