The syndrome of beriberi is characterized by edema, paresis, paralysis with degenerative muscle atrophy, and ultimately cardiac failure.
Most cases are mild, with the most characteristic symptoms being paresthesia and altered reflexes.
The muscle group involved seems to be related to the kind of work an individual with beriberi does. For example, laborers complain of lower leg pain, women who work with their hands speak of pain in their fingers. Muscle cramps often occur at night. Individuals with more serious cases of beriberi suffer from tachycardia, an enlarged heart, and generalized edema. The frequency of the disease seemed to increase during the 19th century, especially affecting people in institutions, such as the army and the navy.