Coughing up blood
Coughing up blood can be caused by a variety of lung conditions. Coughing up blood can take different forms: The blood may be bright red or pink and frothy, or it may be mixed with mucus.
Also known as hemoptysis (he-MOP-tih-sis), coughing up blood, even in small amounts, can be alarming. However, producing a little blood-tinged sputum isn't uncommon and usually isn't serious.
Call 911 or seek emergency care if you're coughing up blood in large quantities or coughing up blood frequently.