What kinds of health problems cause hair loss? mine has been shedding for 3mths. i lost 47lbs since march. thyroid is fine. when will it stop

Stress: Stress is the best cause for these problems but make sure that your doctor knows about this much weight loss. It could point to a serious medical problem.

Have ferritin level: Iron deficiency can cause hair loss and is common in a menstruating woman and with weight loss diets if not supplemented. The best test for iron deficiency is a ferritin level and it should be above 50 to prevent symptoms (the lab 'normal' is usually lower so be sure to find out the level.) also, b vitamin deficiency, especially biotin, can cause hair loss.