A cough can potentially be a symptom of a health concern, but in the overwhelming majority of cases that include a cough, the cause is unrelated to cancer. However, when a cough becomes chronic—in other words, when it lasts for weeks or months, or produces blood—there may be a more serious underlying problem.
A leading cause of a chronic cough is smoking. Smokers can develop a “smoker’s cough,” caused by chemical irritation and inflammation in the lung from tobacco products leading to chronic bronchitis, one form of COPD. These same chemical irritants can lead to other serious lung conditions, such as pneumonia and lung cancer. In other words, although chronic cough in a smoker is not necessarily a sign that someone has lung cancer, it is a signal that cigarettes or other tobacco products are harming the lungs, which is a cause for concern and should prompt a visit to the doctor.
The link between smoking and lung cancer is so strong that all cigarette smokers over the age of 55 with a 30 pack-year smoking history are recommended to receive annual lung cancer screening, which includes a chest CT.
For non-smokers, a chronic cough is less likely to be a sign of cancer. The top three causes of a chronic cough for non-smokers are postnasal drip, asthma, and gastroesophageal reflux disease (GERD). People who do not smoke but have a chronic cough should still see a doctor, even though there is likely no reason for serious concern, to resolve the discomfort that accompanies the cough.
Similarly, coughing blood or bloody sputum (hemoptysis) is more likely to be related to cancer in those who have a history of smoking, though it does not necessarily mean that an individual has lung cancer. Bronchitis, which is a condition characterized by the inflammation of the mucous membrane in the bronchial tubes, is the most common cause of a cough that produces blood. Typically, bronchitis goes away on its own and does not require treatment. If you are coughing up blood clots, if there is blood in the mucus for over a week, or if the blood is accompanied by chest pain, shortness of breath, or fever, you should see a doctor immediately.
For most people, chronic cough and hemoptysis is likely not a reason to believe one has cancer. However, if the issue is prolonged or becomes acute, a doctor can help find the cause of the cough and treat the variety of illnesses that may cause it.
Looking to quit smoking? Learn about the best approaches to quitting from Dana-Farber Cancer Institute.