28th July, 20204 min read

Should I be worried about coughing up blood?

Medical reviewer:
Healthily's medical team
Healthily's medical team
Alex Bussey
Alex Bussey
Last reviewed: 29/07/2020
Medically reviewed

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Coughing up blood (or haemoptysis) can be the symptom of a serious medical condition, and it should always be checked by a doctor, even if it’s just flecks of blood on a tissue or blood-stained phlegm.

If you're coughing up a lot of blood or struggling to breathe, you should call an ambulance or go straight to your nearest emergency room. You may have a life-threatening medical condition that requires immediate treatment.

Coughing up blood can also be a sign of a serious condition like a pulmonary embolism, heart failure or a lung abscess, so it’s important to always get it checked by a doctor.

But it may help to know that coughing up a small amount of blood isn’t always life-threatening. It can be linked to a wide range of medical conditions and experts say that less than 1 in 20 cases are life-threatening.

You may be coughing up small amounts of blood because:

  • you have a chest infection or a persistent cough that’s irritated some of the blood vessels lining your airways
  • a severe nosebleed is causing blood to come out in your saliva

When to worry about coughing up blood

If you're coughing up blood, you should seek medical attention.

The questions a doctor might ask are:

  • how much blood are you coughing up?
  • what colour is the blood you're coughing up?
  • how many times have you coughed up blood?
  • how long have you been coughing up blood for?
  • what other symptoms do you have?

When should you worry about a cough?

Coughing up large amounts of blood

Coughing up large amounts of blood (600ml or more in a 24-hour period) is known as massive haemoptysis. This is a life-threatening emergency that’s often linked to a serious medical condition like lung cancer or bronchiectasis.

Bronchiectasis is where the bronchial tubes of your lungs have become permanently widened and damaged by chronic inflammation.

If you think that you might be having massive haemoptysis, you should go straight to a hospital or call an ambulance.

Doctors will try to stop the bleeding using specialist medication or a procedure such as bronchoscopy or surgery. They'll also order tests so that they can diagnose and treat the underlying cause.

Coughing up dark blood

If you’re vomiting up blood (haematemesis) or coughing up smaller amounts of blood that look dark and like it may contain bits of food or coffee grounds, the blood might be coming from your stomach or digestive system.

This is also a medical emergency, and you will need to see a doctor immediately.

Coughing up red, frothy blood

If you’re coughing up blood that’s bright red and frothy, rust-coloured or blood-stained phlegm, the blood may be coming from your lungs or bronchi (the large tubes going down to your lungs).

Bleeding from the lungs and airways can be linked to a persistent cough or a chest infection like pneumonia or bronchitis.

This doesn't mean that you should ignore your symptoms, or attempt to treat them at home. Other possible causes include a clotting disorder, a lung abscess, lung cancer or heart failure.

You should see a doctor as soon as possible.

What happens when you visit a doctor because you’re coughing up blood?

The treatment for haemoptysis may vary according to the amount of blood that you’ve coughed up and any additional symptoms.

Your doctor will examine you. They may also ask you how much blood you’ve coughed up, or ask you about underlying symptoms to try and work out what’s causing it.

If they think it’s necessary, your doctor may then order blood tests, a chest X-ray or a CT scan to check for any underlying problems.

Doctor looking at chest x-ray in hospital

They may also want to perform a bronchoscopy -- where a thin tube with a light and a camera is inserted through your nose or mouth.

This allows a doctor to see your airways, and check the source of the bleeding.

The results from a bronchoscopy can also be used to make a diagnosis, and may be used to plan your treatment.

Key points

  • coughing up blood should always be checked by a doctor
  • coughing up large amounts of blood or struggling to breathe is a life-threatening emergency
  • small amounts of blood when you cough isn’t always life-threatening, but should still be checked
  • if you’re vomiting up dark blood it might be coming from your stomach — this is a medical emergency
  • your doctor will ask a series of questions and may order blood tests, a chest X-ray or a CT scan
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