Seeing blood when you cough can be alarming, whether it’s a large or small amount. Coughing up blood is often a symptom of a disease.

The seriousness of the condition often depends on how much blood a person is coughing up and how frequently they are doing so.

The blood you cough up may come from your:

  • nose
  • throat
  • upper airways
  • lungs

The medical term for coughing up blood is hemoptysis.

It’s important to contact your doctor anytime you cough up blood, as it may be a sign of a serious respiratory condition.

Get immediate help if:

Blood that comes from the lungs or respiratory tract will often appear bubbly. This is because it mixes with air and mucus in the lungs.

The color can range from rust-colored to bright red. The mucus may be entirely tainted with blood or only contain streaks of blood mixed with mucus.

Bleeding from the mouth (in the case of a cut, for example) is not the same as coughing up blood. If you’re bleeding from your mouth, you may notice it when brushing your teeth or after eating.

A number of different issues can cause a person to cough up blood, ranging from irritation of the throat to lung cancer.

Common causes

When a person has a respiratory illness or strong cough, this can irritate the airways and potentially cause them to cough up blood.

According to 2015 research, in a doctor’s office setting (outpatient visit), the most common causes of coughing up blood are:

In the hospital setting (inpatient), people who are coughing up blood are more likely to have:

However, the most common cause of coughing up blood worldwide is tuberculosis.

Rare causes

There are some potentially serious causes of coughing up blood. These require immediate medical treatment. Examples include:

Certain medical tests and procedures can also have side effects that lead to coughing up blood. These tests and procedures include:

A medical professional can carry out a range of tests to determine what’s causing you to cough up blood.

The medical professional will do an initial physical assessment to determine if you’re in immediate danger. This will include a discussion of symptoms and checking your ability to breathe. A doctor may also try to understand your overall health status by testing your:

  • blood pressure
  • heart rate
  • respiratory rate
  • oxygen saturation

To figure out what’s causing a person to cough up blood, doctors may then order additional tests, including:

  • Blood tests. A doctor will take blood samples to determine what diseases or conditions may be causing the person to cough up blood.
  • X-rays. A radiographer can use these images to look for damage or other issues in the chest.
  • CT angiography. In this test, a person receives an intravenous injection of a special dye before a CT scan. This dye appears as a contrasting tone on CT scan images. Medical professionals can then assess what may be causing bleeding in the lungs and how severe the condition is.
  • Bronchoscopy. A doctor will move a thin tube with a light, called a bronchoscope, into the person’s nose or mouth and down their windpipe to the lungs. A camera on the tool will allow medical professionals to look for visible signs of bleeding.
  • Lung biopsy. In a lung biopsy, a medical professional will remove and examine a piece of tissue from the lung.
  • Lung VQ scan. Doctors may use a lung VQ scan to evaluate blood flow and airflow to the lungs.

Depending on the cause, coughing up blood can be treated in several ways. If the culprit is simple throat irritation due to excessive coughing, over-the-counter throat lozenges and cough suppressants may be enough.

The goals for treatment is to first stop the bleeding, especially large amounts, and then treat the underlying cause. If an infection is the cause, your doctor may prescribe medication.

In cases of severe bleeding, you’ll need to go to the hospital. A doctor may recommend a procedure known as endovascular embolization that stops bleeding. Other procedures or surgeries may be necessary depending on the cause.

Coughing up blood is often a symptom of a disease, condition, or illness. Ignoring the symptom may allow the underlying cause to worsen.

Prevention involves addressing the problem and getting proper treatment. Some lifestyle changes can be beneficial, like quitting smoking (or not starting) or avoiding the outdoors when pollution and smog are high.

If you have a persistent cough, don’t ignore it. Treating this can help prevent you from coughing up blood.

Coughing up blood can be a sign of a serious condition. Even if a doctor might diagnose the cause as something minor, you should always seek medical attention.

Be prepared to describe the appearance of the blood you cough up, including its color and texture.

Call 911 or seek emergency medical attention if you’re coughing up a significant amount of blood, you have other symptoms such as chest pain or shortness of breath, or if the bleeding worsens.