I am 38 female ... and have thinning hair that has got me worried. i have lost 33lbs since march by dieting and walking some.. i have had my thyroid checked and that was not the problem...how can this stop?

Check-up, folic acid: You should keep in contact with your physician to discuss possible odd causes. Thyroid disease, local trauma (blow-drying or chemical products), anorexia nervosa, and genetic predisposition are the most common causes. If your doctor determines those are not the problem, you may want to try taking a multivitamin and 1 mg of Folic Acid to give your hair the vitamins it needs to grow.

See dermatologist: So many reasons outside of thyroid problems for hair loss! you need an expert. A dermatologist is trained to identify causes for hair loss and may be able to offer treatment.