The coughing-up of blood from the lungs. The blood is usually bright red and frothy, thus distinguishing it from blood brought up from the stomach. It is a potentially serious sign of lung disease, although in elderly people haemoptysis may be due to a varicose condition of the small veins in the throat. In young people this condition is often due to bleeding from the nose, in which, owing to the position of the head, the blood runs backwards and is swallowed, instead of running forwards through the nostrils. It should always be brought to medical attention. (See also HAEMORRHAGE; TUBERCULOSIS; PULMONARY EMBOLUS.)