Hemoptysis is the coughing up of blood or bloody sputum from the respiratory tract. The blood can come from the nose, mouth, throat, airway passages leading from the lungs, or the lungs.
Hemoptysis can range from small quantities of blood-stained sputum to life-threatening amounts of blood. Massive hemoptysis is defined as the spitting up of so much blood that it interferes with the patient's breathing. Generally, this is 200 to 600 or more milliliters of blood coughed up within a 24 hour period. Massive hemoptysis is considered a medical emergency. Up to 75 percent of patients with massive hemoptysis die from asphyxiation (lack of oxygen) caused by too much blood in the airways.
Hemoptysis refers specifically to the spitting up of blood that comes from the respiratory tract. Often when persons spit up blood, they are not spitting up blood from the respiratory tract, but from somewhere else. When the blood comes from somewhere other than the respiratory tract, such as from a bloody nose or from the gastrointestinal tract, this is called pseudohemoptysis. Vomiting up blood from the gastrointestinal tract, called hematemesis, is one type of pseudohemoptysis. It is important to distinguish between true hemoptysis and pseudohemoptysis because they often involve very different parts of the body and the treatments are radically different.