The signs and symptoms of pneumonia vary from mild to severe. Many factors affect how serious pneumonia is, including the type of germ causing the infection and your age and overall health. (For more information, go to "Who Is at Risk for Pneumonia?")
See your doctor promptly if you:
- Have a high fever
- Have shaking chills
- Have a cough with phlegm (a slimy substance), which doesn't improve or worsens
- Develop shortness of breath with normal daily activities
- Have chest pain when you breathe or cough
- Feel suddenly worse after a cold or the flu
People who have pneumonia may have other symptoms, including nausea (feeling sick to the stomach), vomiting, and diarrhea.
Symptoms may vary in certain populations. Newborns and infants may not show any signs of the infection. Or, they may vomit, have a fever and cough, or appear restless, sick, or tired and without energy.
Older adults and people who have serious illnesses or weak immune systems may have fewer and milder symptoms. They may even have a lower than normal temperature. If they already have a lung disease, it may get worse. Older adults who have pneumonia sometimes have sudden changes in mental awareness.
Complications of Pneumonia
Often, people who have pneumonia can be successfully treated and not have complications. But some people, especially those in high-risk groups, may have complications such as:
- Bacteremia (bak-ter-E-me-ah). This serious complication occurs if the infection moves into your bloodstream. From there, it can quickly spread to other organs, including your brain.
- Lung abscesses. An abscess occurs if pus forms in a cavity in the lung. An abscess usually is treated with antibiotics. Sometimes surgery or drainage with a needle is needed to remove the pus.
- Pleural effusion. Pneumonia may cause fluid to build up in the pleural space. This is a very thin space between two layers of tissue that line the lungs and the chest cavity. Pneumonia can cause the fluid to become infected—a condition called empyema (em-pi-E-ma). If this happens, you may need to have the fluid drained through a chest tube or removed with surgery.