Ascaris worms cause three kinds of damage: • Larvae in the lung tissue cause Ascaris pneumonitis. Haemorrhage, edema and blockage of alveoli from worms, dead leucocytes and tissue debris are some of the effects • Adult worms cause malnutrition by feeding mainly on the contents of the intestine. They also release toxic wastes that cause allergic reactions. A large number of worms can cause perforations. If this results in peritonitis, it can even be fatal. • Wandering worms cause abscesses in the liver.