Lugol's iodine is a solution of potassium iodide with iodine in water.It is used for a number of purposes, such as
Treatment of iodine deficiency, which can cause goiter, cretinism, and hypothyroidism.
Treatment of hyperthyroidism, which can cause thyroid gland enlargement and overactivity
Protection from radiation exposure, by blocking the intake of radioactive iodine
Antiseptic and disinfectant, for wounds and drinking water
Starch detection, for laboratory and medical tests.