What type of thyriod problem do i have . my dr precribed synthriod.

Hypothyroidism: Generally under active thyroid treated with replacement therapy. Cystic disease of thyroid occasionally treated with replacement so no added stimulus for growth.

Talk with your doc: Dr. Smith is correct. Synthroid (a brand of l-thyroxine, or t4), is thyroid hormone replacement. At 82, it is rare (although not unheard of) to be diagnosed with hypothyroidism (underfunctioning thyroid). It is important for you to discuss with your doctor, so that you have an understanding of why you're taking it. Specifically, what is your diagnosis (you should know your medical problems!).