Hookworm disease is caused by a parasite that infects the intestines. Hookworms are usually found only in the tropics.

Hookworms enter the body by burrowing through the skin of the feet or by being eaten. Once in the body, hookworms attach to the intestinal wall and suck blood, which, in severe cases, leads to anemia.

A hookworm infestation is treated with medicine to kill the worms. Treatment for anemia is sometimes also needed.