Hemoptysis is the medical term for coughing or spitting up blood or bloody mucus from the lungs and throat (respiratory tract). Blood that comes up with a cough often has a bubbly appearance because it is mixed with air and mucus. It is usually bright red, although it may be rust-colored. Sometimes the mucus may only contain streaks of blood. Coughing up blood is not the same as bleeding from the mouth, throat, or gastrointestinal tract. It may be caused by a number of conditions or diseases, such as: a blood clot in the lung, bronchitis, cancer, cystic fibrosis, inflammation of the blood vessels in the lung (vasculitis), injury to the arteries of the lungs, irritation of the throat from violent coughing (small amounts of blood), pneumonia or other lung infections, pulmonary edema, tuberculosis.
Contact your doctor any time you cough up blood, even if you do not have any other symptoms as it can be a sign of a more serious condition.