Pneumonia Symptoms and the Signs to Act On

Pneumonia is an infection in the air sacs at the bottom of the lung, and that depth is what changes the symptoms. Colds and bronchitis stay in the airways above; pneumonia fills the tissue where gas exchange happens, which is why breathlessness and chest pain on inhaling belong to it and rarely to the milder illnesses. MedlinePlus lists fever, chills, cough usually with phlegm, shortness of breath, chest pain when breathing or coughing, nausea, vomiting and diarrhea.

The core picture in adults

• Fever and chills, often with sweating
• Cough with phlegm — the American Lung Association notes it may be greenish, yellow or bloody
• Shortness of breath, and breathing faster than usual
• Chest pain that sharpens when you breathe in or cough
• Fatigue and loss of appetite
• Nausea or vomiting, especially in children
• Confusion, particularly in older people

Not all of it appears at once. Viral pneumonia in particular can open looking like influenza and then deepen over several days, with the cough and the breathlessness taking over.

In older adults, fewer symptoms is not milder disease

This is the most dangerous asymmetry on the page. MedlinePlus reports that older adults may have fewer and milder symptoms and a lower-than-normal temperature, and that they sometimes feel weak or suddenly become confused. New confusion in an older person during a respiratory illness is a reason to seek care that day — not a reason to wait for a fever that may never come.

In babies and children, watch the breathing

The American Academy of Pediatrics puts the emphasis on how a child is breathing rather than on how the cough sounds:

Sign	What it looks like
Fast, labored breathing	Visibly working to breathe, faster than usual at rest
Retractions	Skin pulling in between and around the ribs with each breath
Nasal flaring	Nostrils widening with each breath
Behavior	Less energetic than normal; infants may seem pale and limp

Newborns and infants may show no signs of the infection at all, or may simply vomit, run a fever and cough. Call the pediatrician for trouble breathing, increasing lethargy, or fever lasting more than a few days.

Who is more likely to get seriously ill

MedlinePlus names children under 2, adults 65 and older, people with weakened immune systems, hospital patients, smokers, people with chronic conditions such as diabetes or heart failure, and anyone recently ill with a cold or the flu. For these groups, the threshold to be examined is deliberately low.

Signs that need immediate attention

• Difficulty breathing
• Bluish lips or fingertips
• Chest pain
• High fever
• A severe cough with mucus that keeps worsening
• New confusion, or unusual drowsiness

These come from the American Lung Association’s guidance on when to seek emergency care. Any one of them outranks how long the illness has been going on.

Why a list of symptoms cannot settle it

Pneumonia overlaps heavily with the flu and with bronchitis, which is exactly why it is diagnosed with an exam and imaging rather than by reading. The purpose of knowing the symptoms is to recognize when to be examined — not to rule the diagnosis in or out at home. If your question is really about how long a cough should last, that belongs to persistent cough causes; if it is about the color of what you are coughing up, see yellow mucus meaning; and if the illness started as a sudden fever with aches, compare flu symptoms.

This content is informational and does not replace medical consultation, diagnosis, or treatment.