Why does acute bronchitis cause coughing up phlegm?

Inflammation changes the surface of the bronchi, the tubes that conduct air to the lungs. The lining may release more mucus and the tiny moving hairs that normally carry mucus upwards may work less effectively for a while. A productive cough is the body's way of bringing this material toward the throat where it can be swallowed or spat out.

Coughing Up Phlegm is a very common presentation of Acute Bronchitis. Mucus colour alone does not identify the cause of an illness or show whether antibiotics are needed.

Keep fluids nearby because drinking can make secretions easier to clear. Rest when you can, and reduce exposure to cigarette smoke, shisha smoke, vaping, perfumes, and dusty air. Raise your head with extra pillows if lying flat makes coughing more troublesome.

A pharmacist can advise on products for mucus or discomfort, taking account of pregnancy, allergies, and medicines you already use. Follow the instructions for any prescribed inhaler or other treatment.

Get urgent help for marked breathing difficulty, chest pain, blue or grey lips, confusion, fainting, or blood in phlegm. Arrange medical advice if you are becoming more unwell, have a fever that continues or returns, cannot keep fluids down, or your phlegm is accompanied by worsening breathlessness. Seek earlier guidance if you have chronic lung disease, heart disease, or reduced immunity.

Ask whether your chest symptoms fit acute bronchitis, whether your lungs need examination or testing, and how to use any treatment safely. Tell them about the amount of phlegm, whether there is blood, recent respiratory illness, and any history of asthma or chronic obstructive lung disease.