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 influenza or a cold, and may include:

• Cough, often producing mucus (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 (fatigue) or feeling very weak (malaise).
• Nausea and vomiting.
• Diarrhea.

Symptoms of pneumonia not caused by bacteria (nonbacterial) include fever, cough, shortness of breath, and little mucus when you cough. They may come on gradually and are often less obvious and less severe than those of bacterial pneumonia. Many people don't know that they have nonbacterial pneumonia because they do not feel sick.

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

Older adults and children

Older adults may have different, fewer, or milder symptoms, such as no fever or a cough with no mucus (a dry or nonproductive cough). The major sign of pneumonia in older adults may be when there is 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 per minute.

Conditions that may look like pneumonia include bronchitis, chronic obstructive pulmonary disease (COPD), and tuberculosis.