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Coughing Up Blood


Rebecca Dezube

, MD, MHS, Johns Hopkins University

Last full review/revision Feb 2020| Content last modified Feb 2020

Coughing up blood from the respiratory tract is called hemoptysis. The amount of blood produced can vary from a few streaks of blood mixed with normal sputum to large amounts of pure blood. Other symptoms, such as fever and difficulty breathing, may be present, depending on the cause of hemoptysis.

Causes of Coughing Up Blood

Although hemoptysis can be frightening, most causes turn out not to be serious. Blood-streaked sputum is common in many minor respiratory illnesses, such as upper respiratory infections (URIs) and viral bronchitis. Sometimes the cause is blood from the nose that has traveled down the throat and then is coughed up. Such blood is not considered hemoptysis.

Common causes

Infection is the most common cause (see table Some Causes and Features of Hemoptysis). In adults, 70 to 90% of cases are caused by

In children, common causes are

  • A lower respiratory tract infection
  • A foreign object that has been inhaled (aspirated)

Less common causes

Lung cancer that starts in the lungs is an important cause in smokers over age 40. However, cancer that has spread to the lungs from elsewhere in the body rarely causes hemoptysis. Fungal infection with Aspergillus (called aspergillosis) is increasingly recognized as a cause but is not as common as cancer. Tuberculosis is a possible cause.

Other causes include a blood clot in an artery in a lung (pulmonary embolism) and, less commonly, inflammation of blood vessels (vasculitis) in the lung, such as Goodpasture syndrome or granulomatosis with polyangiitis.

Massive hemoptysis

Massive hemoptysis is the production of more than about a pint (about 600 milliliters) of blood within 24 hours. The most common causes include the following:

Risk factors

Some conditions increase the risk that hemoptysis is caused by a serious disorder:

  • Human immunodeficiency virus (HIV) infection (for Kaposi sarcoma, tuberculosis, and fungal infections)
  • Use of drugs that suppress the immune system called immunosuppressants (for tuberculosis and fungal infections)
  • Exposure to tuberculosis
  • A long history of smoking (for cancer)
  • Recent bed rest or surgery, cancer, a previous occurrence of or a family history of clotting, pregnancy, use of drugs that contain estrogen, and recent long-distance travel (for pulmonary embolism)

Evaluation of Coughing Up Blood

The following information can help people decide whether a doctor's evaluation is needed and help them know what to expect during the evaluation.

Warning signs

In people with hemoptysis, the following symptoms are of particular concern:

  • Large amounts of blood coughed up
  • Shortness of breath
  • Signs of significant blood loss (weakness, dizziness when standing up, thirst, sweating, and a rapid heart rate)
  • Weakness or fatigue
  • Having a tracheostomy

When to see a doctor

People with warning signs should go the hospital immediately. People without warning signs who have risk factors for serious disorders and those with more than just blood-streaked sputum should see a doctor in a day or two.

If people have only blood-streaked sputum (which is usually caused by an upper respiratory infection), a doctor's evaluation is not as urgent. People can call a doctor, who can decide whether and how rapidly they need to be seen based on their symptoms, medical history, and other factors. Typically, a delay of a few days or so is not harmful.

What the doctor does

Doctors first ask questions about the person's symptoms and medical history and then do a physical examination. What doctors find during the history and physical examination often suggests a cause and the tests that may need to be done (Some Causes and Features of Hemoptysis).

Doctors ask

  • When the person started coughing up blood
  • How long the coughing has been going on
  • Whether anything specific triggers it (such as cold, exertion, or lying down)
  • About how much blood is coughed up (such as streaks, a teaspoonful, or a cupful)
  • Whether the person has other symptoms, such as fever, weight loss, chest pain, or leg pain

Doctors determine whether blood was actually coughed (and not vomited or dripped down the back of the throat from a nosebleed).

Doctors ask people about their medical history (if not already known) and their risk factors for causes. A history of frequent nosebleeds, easy bruising, or liver disease suggests a possible blood clotting disorder. Doctors review the drugs the person is taking to check for drugs that inhibit clotting (anticoagulants).

During the physical examination, doctors review vital signs to check for fever, rapid heart or breathing rate, and test for a low oxygen level in the blood. They do a full heart and lung examination, inspect the neck veins for signs of fullness such as bulging, and check the legs for puffiness. Puffiness in one leg may indicate a blood clot (deep vein thrombosis). Puffiness in both legs may indicate heart failure. Doctors also examine the abdomen, skin, and mucous membranes. The person is asked to cough during the examination. If any blood is coughed up, the doctor notes its color and the amount of blood. Doctors also check the nose and mouth for bleeding sites.

Clues from the history and examination help doctors determine the cause. A sensation of postnasal drip or any bleeding from the nose, particularly without coughing, may mean that the blood being coughed up has dripped down the back of the throat from the nose. Nausea and vomiting of black, brown, or coffee-ground–colored material usually means that the blood is from the stomach or intestine and is being vomited and not coughed. Frothy sputum, bright red blood, and, if the amount is massive, a sensation of choking usually mean that the blood is from the trachea or lungs (called true hemoptysis).

If cough has just begun and if the person is otherwise in good health and has no risk factors for tuberculosis, fungal infection, or pulmonary embolism, the cause is usually an acute respiratory infection, such as bronchitis. If coughing up blood is caused by a heart or lung disorder, the person has almost always already been diagnosed with that heart or lung disorder. That is, coughing up blood is usually not the first symptom of a heart or lung disorder.

Some Causes and Features of Hemoptysis


Common Features*


A blood clotting disorder

Use of anticoagulants (as used to treat pulmonary embolism, blood clots in the legs, or atrial fibrillation or to reduce the risk of clots after certain heart procedures)

Use of drugs that dissolve clots (thrombolytic drugs, as used to treat a heart attack or stroke)

Sometimes bleeding from other sites, such as the nose or digestive tract (seen in stool)

In people taking anticoagulants or thrombolytic drugs

Sometimes a family history of a blood clotting disorder

Blood tests that assess the blood's ability to clot


A chronic cough and mucus production in people with a history of recurring infections

High-resolution CT of the chest

Sometimes bronchoscopy


Acute: A cough that may or may not produce sputum (productive or nonproductive) and sometimes symptoms of an upper respiratory infection (such as a stuffy nose)

Chronic: A productive cough on most days of the month or for 3 months of the year for 2 successive years in smokers or in people known to have chronic obstructive pulmonary disease

Acute: A doctor's examination

Chronic: A chest x-ray

Certain long-lasting lung infections (tuberculosis, fungal infections, parasitic infections, or syphilis that affects the lungs)

Fever, cough, night sweats, and weight loss in people known to be exposed to the infection

Often a history of a weakened immune system (immunosuppression) due to a disorder or drug

A chest x-ray

CT of the chest

Testing of sputum samples or samples of fluid from the lungs obtained with a bronchoscope

A foreign object that has been present a long time and has not been identified

A chronic cough (typically in infants or young children) without symptoms of an upper respiratory infection

Sometimes a fever

A chest x-ray

Sometimes bronchoscopy

Heart failure

Frothy, pink sputum, sometimes with blood streaks

Shortness of breath that worsens while lying flat or that appears 1–2 hours after falling asleep

Sounds suggesting fluid in the lungs, heard through a stethoscope

Usually swelling (edema) of the legs

A chest x-ray

Sometimes a blood test to measure a substance that is produced when the heart is strained (called brain natriuretic peptide, or BNP)

Sometimes echocardiography

Lung abscess

Fever, usually for one or more weeks

A cough, night sweats, loss of appetite, and weight loss

A chest x-ray

Sometimes CT or bronchoscopy

Lung cancer

Night sweats and weight loss

Usually in middle-aged or older people with a history of heavy smoking

A chest x-ray




Fever, a feeling of illness, a productive cough, and shortness of breath

Sudden appearance of chest pain when taking deep breaths

Certain abnormal breath sounds, heard through a stethoscope

A chest x-ray

Pulmonary embolism (sudden blockage of an artery in a lung, usually by a blood clot)

Sudden appearance of sharp chest pain that usually worsens when inhaling

Shortness of breath

A rapid heart rate and a rapid breathing rate

Often risk factors for pulmonary embolism, such as cancer, immobility (as results from being bedbound), blood clots in the legs, pregnancy, use of birth control pills (oral contraceptives) or other drugs that contain estrogen, recent surgery or hospitalization, or a family history of the disorder

Specialized lung imaging tests, such as CT angiography or ventilation/perfusion (V/Q) scanning

Pulmonary vasculitis (such as Goodpasture syndrome or granulomatosis with polyangiitis)

Fatigue and weight loss

Sometimes blood in the urine

Sometimes shortness of breath

Sometimes swelling (edema) of the legs

A biopsy of kidney or lung tissue

Blood tests to check for antibodies characteristic of the disorder (antiglomerular basement membrane antibodies, antineutrophil cytoplasmic antibodies)

* Features include symptoms and results of the doctor's examination. Features mentioned are typical but not always present.

† If people have hemoptysis, doctors always take a chest x-ray and measure oxygen levels in the blood with a sensor placed on a finger (pulse oximetry).

CT = computed tomography.


If hemoptysis is severe, persistent, or unexplained, testing is needed. If people have coughed up massive amounts of blood, they are treated and their condition is stabilized before testing is done.

A chest x-ray is taken typically. If the chest x-ray is abnormal or if the person has symptoms of or risk factors for a particular disorder, computed tomography (CT) and bronchoscopy are done. In bronchoscopy, a flexible viewing tube is inserted into the windpipe and bronchi to identify the bleeding site. Occasionally, bronchoscopy is necessary to confirm that blood is being coughed up from the lower airways and not from the nose, stomach, or intestine.

If pulmonary embolism seems possible, doctors do CT using a radiopaque contrast to show blood vessels (called CT angiography) or a scan using a radioactive marker (called a lung perfusion scan). Depending on the results of that scan, pulmonary arteriography may be done.

Doctors often check for lung cancer, especially in smokers over age 40 (and even in younger smokers if they started smoking during adolescence), even if the sputum is only blood-streaked.

In most people, a complete blood count and blood tests that assess the blood's ability to clot are done to detect blood clotting problems.

Despite testing, the cause of hemoptysis is not identified in 30 to 40% of people. However, when hemoptysis is severe, the cause is usually identified.

Treatment of Coughing Up Blood

Bleeding may produce clots that block the airways and lead to further breathing problems. Therefore, coughing is important to keep the airways clear and should not be suppressed with cough suppressants (antitussive drugs).

Hemoptysis may be mild and may stop by itself or when the disorder causing the bleeding (such as heart failure or infection) is successfully treated.

If a large clot blocks a major airway, doctors may have to remove the clot using bronchoscopy.

Rarely, hemoptysis is severe or does not stop by itself. If so, a tube may need to be inserted through the mouth or nose into the windpipe or lower into the airways to help keep the airways open.

If the source of bleeding is a major blood vessel, a doctor may try to close off the bleeding vessel using a procedure called bronchial artery angiography and embolization. Using x-rays for guidance, the doctor passes a catheter into the vessel and then injects a chemical, fragments of a gelatin sponge, or a wire coil to block the blood vessel and thereby stop the bleeding. Sometimes bronchoscopy or surgery may be needed to stop severe or continuing bleeding, or surgery may be needed to remove a diseased or cancerous portion of the lung. These high-risk procedures are used only as last resorts.

If clotting abnormalities are contributing to the bleeding, a person may need a transfusion of plasma, clotting factors, or platelets.

Tranexamic acid, a drug that is inhaled, may be given to treat hemoptysis that does not resolve on its own or with treatment of the underlying disorder.

Key Points about Coughing Up Blood

  • Blood-streaked sputum is usually caused by a respiratory infection and, if it resolves, is not usually cause for worry.
  • A lower respiratory tract infection and inhalation of a foreign object are the most common causes in children.
  • Doctors must distinguish hemoptysis from bleeding that comes from the mouth, nose, or throat and from blood that is vomited.
  • Blood-streaked sputum in people who smoke usually requires further evaluation.
  • People who cough up massive amounts of blood must be treated and stabilized immediately, before testing can be done.

Drugs Mentioned In This Article

Generic Name Select Brand Names
Tranexamic acid CYKLOKAPRON

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