Hi, Based on the information provided it seems like you are on Nutrisystem and your are have been losing my hair, your fingernails are either breaking or bending, and have hot flashes as well as get dizzy. The symptoms of brittle nails is due to low iron in body, the hair loss I due to much required nutrient components like vitamins. Feeling dizziness is sign of low glucose/ sugar in blood. Having hot flashes are due to stress and hormonal changes. Now about is their is problem - answer is you are changing a lot in your body, now as long as you can bear the issues its fine, you can continue your weight loss program. But if not then you need to have some sugar drink if you are feeling dizzy. Now about thyroid- there are two types of thyroid issues one is low thyroid - where you need to have thyroid from outside, other is high thyroid for with medicines need to given to suppress the release or treat the underlying cause for high thyroid gland production. Hope it helps. Dr. JAY PATEL.