Leprosy is a chronic infectious disease caused by bacteria called Mycobacterium leprae which mainly affects the skin, peripheral nerves, membranes of the respiratory tract and the eyes. It is also known as Hansen's disease.

Common signs and symptoms of leprosy include - patches of discolored skin, numbness or tenderness in the hands or feet, nerve damage, secondary infections, sensory loss, deformity of fingers and toes.

Cause of leprosy is an infection by Mycobacterium leprae or Mycobacterium lepromatosis organisms. Risk factors for leprosy include contact with another person infected by leprosy, poverty-stricken conditions, malnutrition and genetic mutations.

Leprosy is not an inherited condition. Since it easily spreads by being in constant, daily contact with a person who is infected, it tends to spread in families.

Leprosy is transmitted from one person to another by nasal droplets. Leprosy is common who live in the areas where the disease is common and where people are in constant, and clos physical contact with infected people. It is also common in those people who handle animals known to carry the bacteria.