Radiation and hypothyroid state

Dear Ask The Doctor: What are the effects of nuclear radiation fallout on someone who already has hypothyroidism?

Dear Ellen: A nuclear fall out and exposure to nuclear radiation leads to exposure of the body to many harmfull chemicals specifically I 131. This further affects the thyroid in its uptake of Iodine thus leading to hypothyroidism. An individual who already has hypothyroidism may thus experiencing worsening of the condition and symptoms. Moreover radiation may also affect the nuclear make up of the cells thus leading to malignant /benign tumors which can develop later on.Radiation may also cause acute radiation thyroiditis which is characterised by local pain and tenderness over the thyroid gland and may lead to an initial increase in expulsion of thyroid hormone and thus lead to transient hyperthyroidism before settling into hypothyroidism.