Cough for 3 weeks: what should you know?

Coughing may linger after a viral infection because the airways remain sensitive. Other possibilities include acute bronchitis, asthma, allergic rhinitis, or mucus draining from the nose. Acid reflux can irritate the throat and trigger cough, sometimes without obvious heartburn. A persistent cough can also reflect a longer-term airway problem such as bronchiectasis or chronic cough. The duration alone does not identify one cause.

A clinician may ask whether the cough is dry or produces mucus, whether it is worse at night or with exercise, and whether you smoke, take medicines, or have asthma. They may listen to your chest and decide whether further checks are needed.

Drink fluids regularly, avoid cigarette smoke and strong fragrances, and use warm drinks to soothe an irritated throat. Rest when needed and note triggers, mucus colour, temperature, wheezing, and changes in breathlessness. Do not start antibiotics or a cough medicine without advice; the right option depends on the cause and your health history. Arrange a primary-care appointment if the cough has reached three weeks, is disrupting sleep, or is getting worse.

Seek urgent help for severe difficulty breathing, blue or grey lips, confusion, fainting, severe chest pain, or coughing up more than a small streak of blood. Arrange prompt medical care for repeated blood, high fever, marked weakness, unexplained weight loss, or a cough that is steadily worsening. People with significant lung disease, reduced immunity, or pregnancy should seek advice sooner.

Ask what features point toward infection, asthma, reflux, or nasal drainage; whether you need a chest examination or other tests; and which symptom treatments are suitable with your regular medicines. Tell the clinician when the cough began and bring a list of medicines and known triggers.