Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. The first thing I d like to tell you that it is not unusual having irregular vaginal bleeding in a hypothyroid condition. The reasons may be: 1. Hypothyroidism reduces sex hormone binding globulin, which increases free serum estrogen resulting in increased bleeding. 2. Hypothyroidism deprives the ovarian follicles of the thyroid hormone they need to develop and ovulate, therefore resulting in progesterone deficiency. This also causes increased bleeding. 3. Hypothyroidism decreases coagulation factors. Simple supplementation with thyroxine (T4) can dramatically lighten periods. Improvement of thyroid autoimmunity (thyroid autoantibodies) with natural interventions such as a gluten-free diet and selenium supplementation. In conclusion, heavy periods occur for many different reasons and are not always easy to treat. Before you resort to more intrusive treatments, please consider if your heavy periods are a consequence of thyroid disease. If they are, then your best treatment is thyroid hormone. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Prabhash Verma