Pneumonia after flu: what to know

Influenza can irritate and weaken the airways, and a second infection may develop in the lungs while you are ill or as you begin to recover. Pneumonia is an infection or inflammation in the lung tissue; it may be caused by viruses, bacteria, or a mixture of factors. A cough that becomes deeper, new fever after improvement, shaking chills, increasing tiredness, or coughing up phlegm deserves attention. These symptoms can also occur with influenza or COVID-19, so symptoms alone cannot identify the cause.

Arrange a same-day clinical assessment if your illness is worsening, especially if breathing feels harder or fever returns. A clinician may listen to your chest, check oxygen levels, and decide whether further tests or treatment are needed. Rest, drink fluids if you can, avoid smoking, and take medicines only as directed. Do not start leftover antibiotics; they may be unsuitable and do not treat every cause of pneumonia.

Seek emergency help for severe breathlessness, blue or grey lips, confusion, fainting, inability to stay awake, or rapidly worsening weakness. Urgent assessment is also needed if you cannot keep fluids down, are passing very little urine, or have severe chest pain. A serious infection can affect the whole body and may lead to sepsis, which requires immediate treatment.

Ask whether your pattern suggests pneumonia, influenza, or another infection; whether your breathing and oxygen need checking; which treatments are appropriate; and what change should prompt a return visit.