Coughing up blood

Coughing or spitting up blood is also known as haemoptysis. The blood can be bright red, rust-coloured, pink and frothy or streaked through sputum (phlegm) or mucus.

The blood you’re coughing up usually comes from your lungs or the airways in your throat. It’s often the result of prolonged coughing or an infection, although it can be caused by a bleeding nose or mouth. It can be alarming but if you are young and otherwise healthy, it is usually not a sign of a serious condition. If you are older, there is more reason for concern, especially if you smoke. 

Occasionally, coughing up blood can be a sign of a serious condition. If you cough up blood that is dark and contains something that looks like coffee granules, or bits of food, the blood may be coming from your digestive system. You should immediately go to hospital.

Sometimes a small amount of blood can mix with your sputum every time you cough — this can also happen as a one-off. However, coughing up any amount of blood, even just a few specks, must always be checked by your GP. To help determine the underlying cause, your GP may ask you about other symptoms, such as: 

• A cough
• A high temperature (fever)
• Breathlessness
• Chest pain
• Feeling unwell
• Wheezing or other lung symptoms

Your chest contains two lungs, with your heart sitting in between the two. When you breathe in, air enters your nose, passes through your throat and voice box (larynx), and into your windpipe (trachea). Your windpipe splits into two branches (bronchi) — the right branch (bronchus) supplies your right lung and the left branch supplies your left lung. 

The bronchi divide further into smaller bronchi, which divide into even smaller branches called bronchioles. At the ends of the smallest bronchioles are tiny sacs called alveoli. Alveoli are lined by a very thin layer of cells and have a strong blood supply — it is here that oxygen enters your blood and carbon dioxide leaves your blood. 

Severe, persistent coughing is one of the most common reasons for coughing up blood. This may be the result of bronchitis, an infection of the airways in your lungs. Bronchitis can be accompanied by:

• Coughing up blood with mucus — once the infection goes away, you will usually stop coughing up blood
• Fever
• Yellow or green sputum (phlegm)

Bronchitis can last for a few weeks (acute bronchitis) or it may be a long-term (chronic) condition. If it is clear that you are coughing up blood because of your infection, no further tests are usually needed. 

If you’re also wheezing or experiencing breathlessness and are bringing up a lot of sputum, you may have a chronic inflammation of your bronchi called bronchiectasis, which makes your lungs prone to infection. Usually only small amounts of blood are coughed up now and then but occasionally a large amount is coughed up. There are several different underlying causes for bronchiectasis, including a past severe lung infection, an inherited condition and other conditions that damage the airways. 

Pneumonia, which is a lung infection, is another common cause for coughing up blood. Other symptoms of pneumonia include breathlessness, flu-like symptoms, chest pain, rapid heartbeat and coughing up blood with mucus.

A severe nosebleed or bleeding from your mouth or throat can also cause you to cough up blood.

Talk to your doctor if you're concerned about your symptoms.

Other, less likely, causes of coughing up blood include:

• An injury to your lung — coughing up blood can happen when a piece of food (eg part of a peanut) or a small object (eg with children, a piece of a toy) is mistakenly inhaled into your lungs; other injuries to your airways or lungs can also cause you to cough up blood
• Cancer — this includes cancer of the throat or windpipe and lung cancer; coughing up blood can be an early sign of lung cancer, which usually develops in the cells lining the bronchi and is most common if you're over 50 and a smoker, although rarer types of lung cancer can affect younger, non-smokers
• Pulmonary embolism — a potentially life-threatening blood clot on the lungs with the main symptoms of sudden breathlessness and chest pain; coughing up blood is a less common symptom
• Pulmonary oedema (fluid on the lungs) — this can cause frothy and bloodstained sputum; if you have a heart condition (eg heart failure), you’re at a higher risk of developing fluid on the lungs 
• Side effects of certain medications, including anticoagulants, which help prevent blood clots
• Tuberculosis (TB) — a relatively rare lung infection that can also cause fever and excessive perspiration

Rare causes of coughing up blood include: 

• Conditions that cause inflammation or abnormal collections of tissue in different parts of the body, including the airways or lungs, such as: 
• Broncholithiasis
• Goodpasture's syndrome
• Granulomatosis with polyangiitis
• Lupus pneumonitis
• Pulmonary endometriosis
• Pulmonary hemosiderosis
• Rare blood vessel problems that cause bleeding in the airways or lungs 

If you’re coughing up a lot of blood, call 999. You should also seek immediate medical attention if you’re vomiting blood as this can be a sign of a serious problem with your digestive system.

If you’re coughing up smaller amounts of blood, see your GP. Your GP will ask you how often you cough up blood, how much blood there is and any other symptoms. They’ll take a sample of your sputum and examine your chest and lungs.

Your GP will try to determine where the blood is coming from; whether it is:

• Coming from your airways below the level of your voice box 
• Coming from your lungs
• Haematemesis — vomiting blood which causes coughing
• Pseudohaemoptysis — blood comes from your mouth or nose and slides to the back of your throat causing you to cough eg during a nosebleed or if you have an inflamed throat

It can be difficult to determine whether coughed up blood is caused by haematemesis or pseudohaemoptysis. If the cause is not clear, your GP may refer you for further investigations, including:

• A bronchoscopy — a tiny camera attached to a thin flexible tube (a bronchoscope) is passed through your nose or mouth, down your throat and into your airways to check your airways and lungs for abnormalities; fibre optics allows a light to be shone via the bronchoscope to help your doctor see clearly inside your airways
• Blood tests — to check for conditions that can cause blood to be coughed up
• Chest X-ray — a quick and easy test to provide an image of your lungs, which can help diagnose a variety of conditions; however, if your condition can’t be diagnosed from a chest X-ray, other tests will be needed
• CT scan — a scan that combines an X-ray with computer technology to provide a clearer image of your lungs compared to a traditional X-ray

In some cases, your GP may refer you to a consultant for further assessment, diagnosis and treatment.

Sometimes, coughing up blood only happens once, clears up on its own or stops once an infection has passed.

If an underlying condition is causing you to cough up blood, your GP or consultant will recommend treatment. The treatment your doctor recommends will depend on your diagnosis and will take into account your general health and preferences.