Blood in a dry cough: what it can mean

Repeated dry coughing can scrape fragile lining in the throat or breathing tubes, leaving a thin red streak. Dry air, smoke, allergies, acid reflux or a recent cold may keep the cough going. Acute bronchitis and asthma can cause coughing without much mucus; bronchiectasis can also cause airway bleeding. A nosebleed or bleeding gum can run backward and be mistaken for blood from the chest. A clinician may need to examine your nose, mouth, throat and chest to locate the source.

Avoid smoke, vaping and dusty air, sip fluids, and use a humidified room if dry air triggers coughing. Keep a note of the colour and amount of blood, how often it appears, and any fever, wheeze, pain or breathlessness. Do not assume that a dry cough makes bleeding harmless. Book a prompt review if it recurs, lasts with the cough or has no clear explanation; take your medicine list to the appointment.

Call emergency services if you cough up a large amount, the bleeding continues, or you develop breathlessness, chest pain, faintness, confusion or blue lips. Get urgent help for rapidly worsening symptoms or severe weakness. Arrange same-day advice when blood appears with a high fever, after a chest injury, or while taking anticoagulants.

Ask whether your throat, nose or lungs are the likely source, whether reflux or allergy treatment could help, and what changes should trigger urgent care. Mention smoking, recent illness and any inhalers.