Is Blood in Sputum a Sign of Cancer?

Hemoptysis is the medical word for coughing up blood from the airways. MedlinePlus describes what it usually looks like: bubbly, because it is mixed with air and mucus, and most often bright red, though it can be rust-colored. Sometimes the mucus carries only streaks.

One distinction matters early. This is not the same as bleeding from the mouth, throat or gut. Blood from a nosebleed running backward, or from bleeding gums, can end up in a tissue and look identical.

Neither source treats small amounts as nothing.

• Emergency care now, per MedlinePlus, for a cough producing more than a few teaspoons of blood. The NHS draws its line at more than just a few spots or streaks.
• Emergency care now, per MedlinePlus, if blood comes with chest pain, severe shortness of breath, dizziness, lightheadedness, fever, or blood in the urine or stools.
• Emergency care now, per the NHS, if there is blood alongside difficulty breathing, a very fast heartbeat, or pain in the chest or upper back. The NHS names the reason: a clot in the lung.
• Contact a provider anyway, per MedlinePlus, any time blood is coughed up, even with no other symptoms. The NHS asks for an urgent appointment for a few spots, flecks or streaks.

One more pattern is worth naming. The NHS lists throbbing pain in one leg, usually the calf or thigh, with swelling and skin that looks red, blue or darkened, as the signs of a deep vein clot. A clot in the leg and a clot in the lung are the same problem in two places.

MedlinePlus adds a warning about self-treatment. Cough suppressants may help when the bleeding comes from coughing hard, but they can block the airway, so they should be checked with a provider first.

One thing neither source does is put a number on outlook. MedlinePlus says only that it depends on the cause, that most people do well once the underlying problem is treated, and that people with severe bleeding may die. There is no percentage attached, and inventing one would be worse than the silence.

MedlinePlus lists fifteen. Lung cancer is one of them. The rest are:

• Bronchitis.
• Bronchiectasis, meaning permanently widened airways.
• Pneumonia and other lung infections.
• Tuberculosis.
• A blood clot in the lung.
• Pulmonary edema, meaning fluid in the lungs.
• Cystic fibrosis.
• Inflammation of the lung's blood vessels, called vasculitis.
• Injury to the arteries of the lung.
• Systemic lupus erythematosus.
• Breathing food or other material into the lungs.
• Blood that is too thin, most often from a blood-thinning medicine above its intended level.
• Irritation of the throat from violent coughing, which produces small amounts.
• Bronchoscopy with biopsy, as a known effect of the test itself.

That last group explains a lot of cases. A week of hard coughing with a chest infection can tear small vessels in an irritated airway. So can a recent procedure. It is also worth checking the medicine list before assuming anything, since blood thinners appear on this list in their own right.

NCI's summary on non-small cell lung cancer lists coughing up blood among the presenting features. The others it names are a worsening cough, chest pain, weight loss, breathlessness and hoarseness.

That combination is the thing to notice, rather than the blood alone. NCI also describes symptoms from pressure on nearby structures: trouble swallowing when the esophagus is squeezed, hoarseness when the nerve to the voice box is caught, and swelling of the face and neck veins when the large vein draining the head is compressed.

Smoking history changes the weight a clinician gives all of this. NCI reports that smoking raises lung cancer risk about tenfold on average against a lifetime nonsmoker, defined as someone who has smoked fewer than 100 cigarettes, and that former smokers stay at raised risk for years. For a separate look at the same symptom, see coughing up blood and a persistent cough.

MedlinePlus publishes the questions, which makes them a useful list to prepare against:

• How much blood, and is it large amounts at a time?
• Is it blood-streaked mucus rather than blood alone?
• How many times has it happened, and how often?
• How long has this been going on, and is it worse at any particular time, such as at night?
• What other symptoms are there?
• Is any blood-thinning medicine being taken?

MedlinePlus also suggests keeping track of how long the bleeding continues and how much blood is mixed with the mucus. That record is more useful than a memory of one alarming morning.

A complete physical examination comes first, with the chest and lungs checked. MedlinePlus then lists the tests that may be done:

• Chest x-ray.
• Chest CT scan.
• Bronchoscopy, which looks directly inside the airways.
• Complete blood count.
• Clotting tests such as PT with INR, or PTT.
• Sputum culture and smear.
• A lung scan, pulmonary arteriography, or a lung biopsy.

Which of these gets ordered depends on the pattern, the examination and the risk factors, not on the word "blood" by itself. A clotting test and a blood count answer a different question from a CT scan. The first asks whether the blood itself is behaving; the second asks what the lung looks like. For the broader picture of how symptoms are worked up, see symptoms of cancer.

The thresholds above are the ones the two agencies publish. Set out as actions, they look like this.

• Call 911 or go to an emergency department if you cough up more than a few teaspoons of blood, which is the MedlinePlus line, or more than just a few spots or streaks, which is where the NHS draws it. Go now if blood comes with chest pain, severe shortness of breath, dizziness or lightheadedness, fever, or blood in your urine or stools. The NHS adds difficulty breathing, a very fast heartbeat, and pain in the chest or upper back, and names the reason: a clot in the lung. Do not drive yourself.
• Call your care team the same day if you cough up any blood at all, even a streak, and even with no other symptom. MedlinePlus says to contact a provider any time blood is coughed up. The NHS asks for an urgent appointment for a few spots, flecks or streaks. Call the same day too for throbbing pain in one leg, usually the calf or thigh, with swelling and skin that looks red, blue or darkened. That is a clot in the leg, which is the same problem as a clot in the lung, one step earlier.
• Ask before you treat it. MedlinePlus warns that cough suppressants can block the airway, so check with a provider first rather than reaching for one.

• https://medlineplus.gov/ency/article/003073.htm
• https://www.nhs.uk/conditions/coughing-up-blood/
• https://www.nhs.uk/conditions/deep-vein-thrombosis-dvt/
• https://www.cancer.gov/types/lung/hp/non-small-cell-lung-treatment-pdq