Coughing up a little blood: what it can mean

Blood-streaked mucus may appear after forceful or repeated coughing because the lining of the nose, throat, or airways becomes irritated. Acute bronchitis and a common cold can produce inflamed airways and phlegm. Blood may also be swallowed from a nosebleed or irritated gums rather than coming from the lungs. Asthma, bronchiectasis, and other airway conditions can present with cough and blood-stained sputum. Acid reflux or allergic rhinitis can drive ongoing cough, which may further irritate tissues. The appearance and source need clinical context.

Note the colour and amount, whether it is mixed through mucus or appears fresh, and whether it follows a nosebleed or severe coughing. Avoid smoking and strenuous activity until you have advice. Contact a clinician promptly even if the amount seems small, particularly when you take blood-thinning medicine or have a known lung condition. Do not start leftover antibiotics or cough medicines without guidance.

Seek emergency help if bleeding is more than a few streaks, continues, or is accompanied by shortness of breath, chest pain, rapid heartbeat, dizziness, fainting, blue lips, or severe weakness. Prompt review is also needed for fever, night sweats, unexplained weight loss, or a cough that does not settle. A clinician may check your oxygen level, chest, nose, and throat and decide whether further tests are needed.

Could the blood be from my nose or throat rather than my chest? Does my medication increase bleeding? Which symptoms should send me to emergency care? Do I need an examination or chest imaging?