Definition of pneumonia

What is pneumonia? Pneumonia is an infection of one or both of the lungs caused by bacteria, viruses, or fungi. It is a serious infection in which the air sacs fill with pus and other liquid. • Lobar pneumonia affects one or more sections (lobes) of the lungs. • Bronchial pneumonia (also known as bronchopneumonia) affects patches throughout both lungs. What causes pneumonia? There are more than 30 different causes of pneumonia, and they’re grouped by the cause. The main types of pneumonia are: • Bacterial pneumonia. This type is caused by various bacteria. The most common is Streptococcus pneumoniae. It usually occurs when the body is weakened in some way, such as by illness, poor nutrition, old age, or impaired immunity, and the bacteria are able to work their way into the lungs. Bacterial pneumonia can affect all ages, but you are at greater risk if you abuse alcohol, smoke cigarettes, are debilitated, have recently had surgery, have a respiratory disease or viral infection, or have a weakened immune system. • Viral pneumonia. This type is caused by various viruses, including the flu (influenza), and is responsible for about one-third of all pneumonia cases. You may be more likely to get bacterial pneumonia if you have viral pneumonia. • Mycoplasma pneumonia. This type has somewhat different symptoms and physical signs and is referred to as atypical pneumonia. It is caused by the bacterium Mycoplasma pneumoniae. It generally causes a mild, widespread pneumonia that affec...

What Are the Symptoms of Pneumonia? Pneumonia symptoms can vary from so mild you barely notice them, to so severe that hospitalization is required. How your body responds to pneumonia depends on the type germ causing the infection, your age and your overall health. The signs and symptoms of pneumonia may include: Bacterial pneumonia, which is the most common form, tends to be more serious than other The symptoms of viral pneumonia usually develop over a period of several days. Early symptoms are similar to 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. Older adults who have pneumonia sometimes have sudden changes in mental awareness. For individuals that already have a chronic lung disease, those symptoms may worsen. When to call a doctor If you think you or your child has symptoms of pneumonia, don't wait for the disease to get even worse before you seek care. Call your doctor. And see your doctor right away if you have difficulty breathing, develop a bluish color in your lips and fingertips, have chest pain, a high fever, or a cough with mucus that is severe or is getting worse. It's especially important to get medical attention for pneumonia if you are in a ...