Most people infected with hookworm don't have any symptoms. The larvae of animal hookworms sometimes get into the skin, usually after lying on sand contaminated by animal faeces while on a beach holiday abroad.

These larvae are unable to go further into the body, but cause a slowly moving red line to appear on the skin. This is called cutaneous larva migrans and can last several weeks. It's a bit itchy, but doesn't usually cause any harm.

People infected with human hookworm larvae occasionally have a less obvious itchy rash for a few days around the area of skin where the larvae penetrated. Respiratory symptoms such as a cough and wheeziness may develop when the larvae reach the lungs, a few weeks after exposure. Severe infections may cause abdominal (tummy) pain, diarrhoea, loss of appetite, weight loss, fatigue and anaemia. Blood loss leading to iron deficiency anaemia and protein loss are the most serious symptoms.