The presence of blood pigment in the URINE caused by the destruction of blood corpuscles in the blood vessels or in the urinary passages. It turns urine a dark red or brown colour. In some people this condition, known as intermittent haemoglobinuria, occurs from time to time, especially on exposure to cold. Haemoglobinuria is also produced by various poisonous substances taken in the food. It occurs in malarious districts in the form of one of the most fatal forms of MALARIA: BLACKWATER FEVER. (See also MARCH HAEMOGLOBINURIA.)