Beriberi, BEHR ee BEHR ee, is a disease caused by a lack of vitamin B-1, or thiamine. The name is taken from the Sinhalese, and means I cannot, because the victim is too sick to do anything. Beriberi is characterized by stiffness of the lower limbs, paralysis, and pain. Muscle tissue gradually breaks down, and anemia develops. In advanced cases, the nervous system is affected.