What causes pneumonia in older adults?

Bacteria and viruses can inflame the air sacs where oxygen passes into the blood. Influenza and COVID-19 are examples of viral illnesses that can affect the lungs; bacterial pneumonia can occur after a respiratory infection or develop on its own. Swallowing difficulties, drowsiness, reflux, or a weak cough can allow saliva, food, or stomach contents into the airways. Older adults may have less obvious symptoms, such as new confusion, unusual sleepiness, weakness, or reduced appetite rather than a high fever. Existing lung or heart disease can make infection harder to tolerate.

Arrange medical assessment if an older person develops a new cough, fever, chills, breathlessness, chest discomfort, marked weakness, or a change in alertness. A clinician may listen to the chest, check oxygen levels, and decide whether testing or treatment is needed. Encourage small sips of fluid if swallowing is safe, rest, and keep a record of symptoms and medicines. Do not start leftover antibiotics; the cause may be viral, and the wrong treatment can delay appropriate care. Read more about [Pneumonia](/conditions/pneumonia/), [Influenza](/conditions/influenza/), or [COVID-19](/conditions/covid-19/).

Seek emergency help for severe difficulty breathing, blue or grey lips, inability to stay awake, sudden confusion, fainting, or rapidly worsening weakness. Urgent assessment is also needed when an older person cannot keep fluids down, has very little urine, or has a cough with worsening breathlessness. These features can signal low oxygen, dehydration, or a serious infection such as [Sepsis](/conditions/sepsis/). A mild cough can still deserve prompt review in someone frail or living with significant medical conditions.

Ask: Could swallowing or reflux be contributing? Does the person need a chest examination or oxygen check? Which warning signs should prompt emergency help? How should regular medicines be taken during illness? If coughing up phlegm, fever, or [Chills](/symptoms/chills/) occur, mention when they began and whether symptoms are changing.