Symptoms

In otherwise healthy adults

Bacterial pneumonia. Symptoms of pneumonia caused by bacteria in otherwise healthy people younger than 65 usually come on suddenly. They often start during or after an upper respiratory infection, such as the flu or a cold. Symptoms may include:

• Cough, often producing mucus, also called sputum, from the lungs. Mucus may be rusty or green or tinged with blood.
• Fever, which may be less common in older adults.
• Shaking, "teeth-chattering" chills, one time only or many times.
• Fast, often shallow, breathing and the feeling of being short of breath.
• Chest wall pain that is often made worse by coughing or breathing in.
• Fast heartbeat.
• Feeling very tired or weak.
• Nausea and vomiting.
• Diarrhea.

Nonbacterial pneumonia. Symptoms of pneumonia not caused by bacteria may come on gradually and are often not as bad or as obvious as symptoms of bacterial pneumonia. Many people don't know that they have nonbacterial pneumonia, because they don't feel sick. But symptoms may include:

• Fever.
• Cough.
• Shortness of breath.
• Little mucus when you cough.

When symptoms are mild, your doctor may call your condition "walking pneumonia."

In older adults and children

Older adults may have different, fewer, or milder symptoms, such as having no fever or having a cough with no mucus (a dry or nonproductive cough). The major sign of pneumonia in older adults may be a change in how clearly they think (confusion or delirium) or when a lung disease they already have gets worse.

In children, symptoms may depend on age:

• In infants younger than 1 month of age, symptoms may include having little or no energy (lethargy), feeding poorly, grunting, or having a fever.
• In children, symptoms of pneumonia are often the same as in adults. Your doctor will look for signs such as cough and a breathing rate over 60 breaths a minute.

Some conditions with symptoms similar to pneumonia include bronchitis, COPD, and tuberculosis.