Most people who are infected with the parasitic worms that cause lymphatic filariasis do not have symptoms. However, some people develop lymphedema - massively swollen limbs or genital areas - when the worms block the normal flow of lymph in the body. Lymphedema can be very serious, because the skin of the affected area can become infected. The infection can cause illness and death. Some people with lymphatic filariasis don't develop lymphedema but have kidney damage and damage to the lymphatic system from the worms.