When the immune system attacks COVID-19 in the lungs, they can become inflamed and fill with fluid, leading to pneumonia. About 15 percent of those with COVID-19 develop serious complications, including pneumonia, which involve hospitalization and oxygen assistance. Broadly speaking, pneumonia is responsible for about one million adult hospitalizations and 50,000 deaths per year in the United States. It is the second most common reason for adult hospitalizations — after childbirth — and it is the most common reason for child hospitalizations, according to the Cleveland Clinic. The terminology surrounding pneumonia may be confusing, but it’s important to understand the facts. Here are 10 pneumonia terms you should know: Alveoli These air sacs in your lungs help transport oxygen into the bloodstream, according to the National Cancer Institute. They can fill up with fluid or pus when a person develops pneumonia, an acute respiratory infection, resulting in shortness of breath, chest pain, dizziness, sweating, and rapid heartbeat. These flu-like symptoms that persist for weeks often don’t respond to over-the-counter cold and sinus medicines. Aspiration Pneumonia This is a type of pneumonia caused by breathing food or liquid into your lungs. These substances cause irritation in your lungs, and an infection may follow. You could be at risk for aspiration pneumonia if you vomit when drunk, have a neurological disease that interferes with your ability to swallow (such as seizure disorders, Parkinson’s disease, dementia, or history of stroke), or if stomach acid seeps up into your throat at night — a condition known as gastroesophageal reflux disease, or GERD. Atypical Pneumonia These pneumonias don’t have the usual symptoms of bacterial pneumonias, causing less fever, less cough, and less mucus production. Atypical pneumonias include Legionnaires’ disease, which is caused by the Legionella pneumophila bacteria. This can be caught by inhaling infected droplets from air conditioning systems, spas, or fountains. A Chlamydophila pneumoniae infection causes a mild, atypical pneumonia seen in older people. Mycoplasma pneumoniae bacteria can also cause a kind of atypical pneumonia often called “walking pneumonia.” This is because the symptoms are usually mild, according to the Centers for Disease Control and Prevention. Bronchial Pneumonia Any pneumonia can affect your lungs in two basic ways, and it is described accordingly as either bronchial or lobar. Bronchial pneumonia occurs in patches throughout both lungs. The term “bronchial” means that the airways throughout the lungs are also involved with the infection. People with asthma and bronchitis are at risk for pneumonia because mucus production blocks these passages. Double Pneumonia This is a descriptive term for any type or cause of pneumonia that affects both lungs. Influenza, or Flu This is an acute respiratory illness caused by influenza A or B viruses. While most patients recover in a couple of weeks, it can lead to potentially serious complications, such as pneumonia. Lobar Pneumonia This term describes pneumonia that settles in a section of your lung called a lobe. Lobar pneumonia is usually caused by pneumococcus bacteria, and tends to be more serious and extensive. Mycoplasmal Pneumonia This pneumonia may be described as both atypical and walking pneumonia. It’s caused by a tiny type of bacteria called Mycoplasma pneumoniae. These infections are more common in young people and spread like a common cold in tight living conditions. The symptoms, which are similar to those of the flu, can usually be treated with antibiotics. This type of pneumonia usually doesn’t require a hospital stay, which is why a mycoplasmal infection is sometimes called walking pneumonia. Opportunistic Pneumonia This term describes all pneumonias that attack anyone with a weakened immune system. The germs that cause these pneumonias usually don’t make healthy people sick. An example is pneumocystis pneumonia, caused by Pneumocystis jirovecii, which was once considered a parasite but is now classified as a fungus. Opportunistic pneumonias are most common in people who have HIV or AIDS, are undergoing cancer treatment, or who had an organ transplant. Walking Pneumonia This simply means that a person with a mild case of pneumonia is well enough to “walk around.” About one-third of pneumonia cases are caused by viruses, and they tend to be less serious than bacterial pneumonias. The term walking pneumonia is also used to describe atypical pneumonia and mycoplasmal pneumonia.
