Blood in the sputum is also known as haemoptysis. Sputum is usually the mucus substance you cough up from the airways and lungs. Phlegm is the specific term for the mixture of saliva and mucus from your nose, mouth and throat. There can be different causes for haemoptysis, some are serious, some are less so, but you should see your doctor in most circumstances, so they can work out the underlying cause. You may notice a few streaks in the sputum, which commonly come with a chest infection, or clots, or even a pink watery appearance, but these indicate an area of tissue damage, and warrant a discussion with your doctor.
To work out the cause, it’s worth thinking about the different parts of your breathing system, to work out where it’s coming from. Let’s think about the lungs first. Chest infections are the most likely cause of haemoptysis, especially pneumonia or tuberculosis (TB). Bronchiectasis is a long term condition that causes the airways to enlarge and produce more mucus, and makes getting rid of chest infections more difficult – this may cause a bit of trauma in the lungs that comes up as blood in the sputum. A cancer in the lung can produce haemoptysis, and those who have smoked tobacco or cannabis for years should have a low bar for seeing the doctor if they cough up blood. A potentially life-threatening cause of haemoptysis, or more specifically coughing up a pink froth, is a blood clot in the lungs, known as a pulmonary embolism. There are certain risk factors for this, and you might feel quite unwell. A problem in the nose might cause nosebleeds and nasal infections, bleeding in the mouth can be caused by certain oral infections and gum disease, bleeding from the throat can come from vomiting, throat infections or severe coughing, Cancer can occur in the throat and mouth, and this is more common in those that smoke or chew tobacco or other substances. Blood-thinning medication like warfarin and aspirin can cause some bleeding from the respiratory system, or exacerbate any of these causes. Trauma of any part can cause bleeding, and inhaling a foreign body is one to consider, especially in young children.
If you are bringing up blood by itself or with minimal sputum then that is an immediate cause for concern. If you notice blood coming from anywhere else or you are having difficulty breathing, chest pain, weakness, unexplained weight loss or fatigue then you should also seek immediate attention. If you have been a smoker or ex-smoker for many years, or a particularly heavy smoker for a few years, and have blood in your sputum, you should see your doctor with urgency. It’s even more important if you have other symptoms like unexplained weight loss, excessive fatigue or a persistent cough. This is also true for cannabis smokers or any smokers of anything else. If you’ve had a cough lasting more than 3 weeks that you can’t shift, you should see your doctor.
Your doctor will ask about your symptoms and how it started, for example, with a cough or a chest infection, whether you have any cancer or TB risks. They will have a listen to your lungs, check your mouth and throat, and assess your breathing rate. Providing a picture of the sample may be useful and your doctor may also request a sample of your sputum to send to the lab for testing. Blood tests can be helpful in deciding if this is an infection or a blood clot. If your symptoms do not improve or they have any other concerns, they may request a chest X-ray. Further investigation is usually done by a specialist called a respiratory physician, and they will organise a more detailed picture of your lungs called a CT scan. They may also put a tube with a camera (bronchoscope) into your airways to look for any abnormalities and take some samples.
Treatment depends very much on the cause – this is a symptom of an underlying problem. If your doctor suspects an infection, they will treat you with a course of antibiotics. If you are coughing up blood due to coughing repeatedly and severely, you should speak with your doctor before trying any cough suppressants, to ensure there is nothing more concerning going on. If cancer is suspected, then depending on the location, a combination of surgery, chemotherapy or radiotherapy will be offered.