Beriberi

Beriberi is a nervous system ailment caused by thiamine (vitamin B1) deficiency; its symptoms include weight loss, emotional disturbances, impaired sensory perception (Wernicke's encephalopathy), weakness and pain in the limbs, and periods of irregular heart rate. Edema (swelling of bodily tissues) is common. In advanced cases, the disease may cause heart failure and death.

Beriberi was one of many disease American soldiers stranded on the Bataan Peninsula in 1942 had to deal with.