Beriberi is a condition that occurs in people who are deficient in thiamine (vitamin B1). There are two types of beriberi: wet and dry. Wet beriberi affects the cardiovascular system and can cause increased heart rate, shortness of breath, and swelling of the lower legs. Dry beriberi affects the nervous system and can cause difficulty walking, loss of feeling in the hands and feet, paralysis of the lower legs, mental confusion, speech difficulty, pain, and vomiting. This condition is rare in the United States. Alcohol abuse increases the risk of developing beriberi.