Pneumonia: Signs, Symptoms and Risk Factors

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Woman in bed with a fever
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Pneumonia is an infection that occurs in the lungs. It can be in one lung or both, and can range from mild to life-threatening. Some cases of pneumonia will cause a problem in one lobe (segment) of one lung, while serious cases can affect all 5 lobes of the lungs. The more lobes that are involved, the more serious the pneumonia is likely to be.

Pneumonia is often caused by bacteria, but can also be caused by a virus or even fungus in rare cases. Treatment typically includes one or more antibiotics. These may be taken by mouth when the pneumonia can safely be treated at home, or more require IV treatment in more serious cases.

Pneumonia causes sputum, a fluid that may look like pus during a bout of pneumonia, to collect in the lungs. This leads to a severe cough in many cases, as a cough is the body’s way of trying to eject this fluid from the lungs. This fluid collection makes the body work much harder to get enough oxygen for normal daily activities.

Risk Factors

The patients at greatest risk for pneumonia are the very young and the older population. While people of any age can get pneumonia, most cases are in children and people who are over 65. Individuals with chronic health problems, such as diabetes, are at higher risk than the average person, as are people with chronic respiratory problems.

Individuals who have weakened immune systems, such as people with cancer or HIV, and those taking medications that suppress the immune system are also at increased risk of developing pneumonia.  Individuals who aspirate, meaning their food, vomit or even saliva accidentally goes into the airway instead of the esophagus, are at high risk for pneumonia.

Surgery patients are at high risk for pneumonia for several reasons. These patients are unable to cough or protect their airway while they are under anesthesia. This means that if they were to vomit during surgery they would be unable to start coughing to try to remove the foreign material from their lungs. This type of pneumonia is called aspiration pneumonia, and can be very serious. Surgery patients also can have difficulty coughing after surgery due to pain. They avoid coughing because it makes their surgical pain worse, but then secretions are able to build up in the lungs and lead to chest congestion or pneumonia. The pooling of secretions in the lungs is a risk factor for pneumonia.

Signs and Symptoms

The signs and symptoms of pneumonia can vary from person to person. One person may be short of breath while another may experience only a severe cough. Here are the most common signs and symptoms of pneumonia:

  • Fever and/or chills
  • Productive cough, often severe and may be green in color
  • Shortness of breath
  • Difficulty breathing
  • Chest pain when coughing or breathing deeply
  • Feeling weak
  • Feeling tired
  • Changes in mental status
  • Loss of appetite
  • Nausea or vomiting


Pneumonia is more likely in people who have chronic illnesses, and surgery is often the result of chronic illness.

Preexisting conditions mean many patients are at risk for pneumonia before they even have surgery. Once in surgery, the patient may be “asleep” for several hours, and even longer while in recovery in the days following surgery. Being in bed instead of being up and moving can contribute to the development of pneumonia.

Pain often prevents surgery patients from breathing as deeply as they normally would, and it also makes people avoid coughing. Shallow breathing and not coughing when appropriate also increases the risk of pneumonia. Having chest surgery, in particular, increases the risk of pneumonia because coughing is so painful.

It is also important to know that hospital-acquired pneumonia, that is pneumonia that an individual contracts in the hospital, is known to be more severe than pneumonia that one contracts from the community (friends, family, neighbors).


For some patients, the pneumonia vaccine may be appropriate, depending up their age and medical history. In addition, walking as early as possible after surgery is a great way to stay healthy and recover quickly. Coughing when the urge strikes is important, rather than stifling the urge because coughing is painful. Bracing with a pillow can help minimize pain when doing so.


The most common treatment for pneumonia is antibiotic medications, respiratory treatments and incentive spirometry exercises along with coughing exercises. Antibiotic therapy is typical, but that approach only works for bacterial pneumonia and some cases are caused by viruses. Treatment for pneumonia varies widely based on the cause of the infection and the severity of symptoms. In cases where the patient is having trouble getting enough oxygen, a hospital stay is typically required and supplemental oxygen may be provided.

Severe cases may require ICU level care, intubation and the use of a ventilator along with around the clock care, but these are uncommon.


NIH. Who Is At Risk For Pneumonia.