Coughing up blood is the spitting up of blood or bloody mucus from the lungs and throat (respiratory tract).

Hemoptysis is the medical term for coughing up blood from the respiratory tract.

Coughing up blood is not the same as bleeding from the mouth, throat, or gastrointestinal tract.

Blood that comes up with a cough often looks bubbly because it is mixed with air and mucus. It is usually bright red.

A number of conditions, diseases, and medical tests may make you cough up blood.

Diseases and conditions may include:

• Bleeding gums such as with gingivitis
• Blood clot in the lung
• Bronchiectasis
• Bronchitis
• Cystic fibrosis
• Esophageal cancer
• Goodpasture's syndrome
• Irritation of the throat from violent coughing
• Nosebleed
• Laryngitis
• Lung cancer (see metastatic lung cancer)
• Pneumonia
• Pulmonary aspiration (inhaling blood into the lungs)
• Pulmonary edema
• Systemic lupus erythematosus
• Tuberculosis
• Wegener's granulomatosis

Diagnostic tests that may make you cough up blood may include:

• Bronchoscopy  
• Laryngoscopy  
• Lung biopsy
• Mediastinoscopy
• Spirometry
• Tonsillectomy
• Upper airway biopsy  

Cough suppressants may help if this condition is due to throat irritation from violent coughing. However, cough suppressants may lead airway obstruction in some cases. Always check with your doctor first.

It is very important to note how long you cough up blood. You should also keep track of the following:

• How much blood is mixed with the mucus
• Symptoms such as lightheadedness, dizziness, or thirst, which might indicate a severe amount of blood loss
• Other symptoms such as fever, chest pain, shortness of breath, and blood in the urine

If there is any unexplained coughing up of blood, call an ambulance or go to the nearest emergency department. This is very important if your cough produces large volumes of blood (more than a few teaspoons), or if it is accompanied by severe shortness of breath, lightheadedness, or dizziness.

In emergency cases, your doctor will give you treatments to control your condition. You will then be asked questions about your cough such as:

• Type
  • Can you see blood when you cough up something? 
  • Is there blood-streaked mucus (phlegm)?
  • Are large amounts of blood (massive hemoptysis) coughed up?
  • How many times have you coughed up blood?
• Time pattern
  • Is the cough worse at night?
  • Did it begin suddenly?
  • Has it increased recently?
  • How many weeks has the cough lasted?
  • What other symptoms do you have?

The doctor will do a complete physical exam and check your chest and lungs. Tests that may be done include:

• Chest x-ray
• Chest CT scan
• Complete blood count
• Coagulation studies such as PT or PTT
• Bronchoscopy
• Lung biopsy
• Lung scan
• Pulmonary arteriography
• Sputum culture and smear

Rakel RE. Textbook of Family Practice. 6th ed. Philadelphia, Pa: WB Saunders; 2005:402-413.

Murray J, Nadel J. Textbook of Respiratory Medicine. 3rd ed. Philadelphia, Pa: WB Saunders; 2000:497.