If you cough up blood

Blood may be mixed with phlegm after repeated or forceful coughing. Acute bronchitis and a common cold can irritate the breathing tubes; asthma, bronchiectasis and chronic cough are other airway conditions that may be associated with blood-streaked mucus. Acid reflux or allergic rhinitis can contribute to coughing, while bleeding in the nose or mouth can be mistaken for blood from the chest.

Tell a clinician whether the blood was bright red, rusty or dark, whether it was streaked through mucus, and whether it happened once or repeatedly. Also mention fever, chest pain, shortness of breath, dizziness, recent travel and medicines that affect clotting.

Sit upright, avoid exertion and seek medical advice for a new episode, even if the amount seems small. Note what you saw and bring your medicine list. Do not use leftover antibiotics or alter prescribed blood-thinning medicine on your own.

A clinician may inspect the nose and throat, listen to your chest and decide whether tests are needed. If the bleeding stops but returns, arrange reassessment rather than waiting for it to settle by itself.

Call emergency services for ongoing or substantial bleeding, breathing difficulty, chest pain, faintness, confusion, blue lips or rapid worsening. Seek same-day care for repeated episodes, fever with worsening cough, marked weakness or blood while taking an anticoagulant.

Ask whether the blood is coming from the airways or upper airway, whether a medicine could be contributing, and which tests may clarify the cause. Ask what amount or symptom should prompt emergency care if it happens again.