Pneumonia: What is it? Symptoms, Types, Causes, Diagnosis and Treatment

It is an infection in one or both lungs. It can be caused by bacteria, viruses or fungi.

Bacterial pneumonia is the most common type in adults.

Pneumonia causes inflammation in the alveoli of the lungs. The alveoli become filled with fluid or pus, which makes breathing difficult.

Pneumonitis vs. Pneumonia

Both pneumonia and pneumonia are terms used to describe the inflammation in your lungs.

In fact, pneumonia is a type of pneumonitis. If your doctor diagnoses you with pneumonitis, they usually refer to inflammatory lung conditions other than pneumonia.

Pneumonia is an infection caused by bacteria and other germs. Pneumonitis is a type of allergic reaction. It occurs when a substance such as mold or bacteria irritates the alveoli of the lungs.

People who are especially sensitive to these substances will have a reaction. Pneumonitis is also called hypersensitivity pneumonitis.

Pneumonitis is treatable. However, it can cause permanent scarring and lung damage if it is not detected early enough.


The symptoms of pneumonia can be mild or life-threatening. The most common symptoms of pneumonia may include:

  • Cough that can produce phlegm.
  • Fever, sweating and chills.
  • Difficulty breathing.
  • Chest pain.

Other symptoms may vary depending on the cause and severity of the infection, as well as the age and general health of the individual.

Symptoms for cause

Viral pneumonia can start with symptoms similar to those of the flu, such as wheezing. A high fever can occur after 12 to 36 hours.

Bacterial pneumonia can cause fever of up to 105 ° F along with profuse sweating, bluish lips and fingernails and confusion.

Symptoms by age

Children under 5 years old can have rapid breathing.

Babies can vomit, lack energy, or have problems drinking or eating.

Older people may have a lower body temperature than normal.

Types and causes

The main types of pneumonia are classified according to the cause of the infection, where the infection was transmitted and how the infection was acquired.

Types by germ

Pneumonia can be classified according to the organism that caused the infection.

Bacterial pneumonia : Streptococcus pneumoniae is the most common cause of bacterial pneumonia. Chlamydia pneumonia and Legionella pneumophila can also cause bacterial pneumonia.

Viral pneumonia : Respiratory viruses are often the cause of pneumonia, especially in young children and the elderly. Viral pneumonia is usually not serious and lasts less than bacterial pneumonia.

Mycoplasma pneumonia : Mycoplasma organisms are not viruses or bacteria, but they have features common to both. Mycoplasmas usually cause mild cases of pneumonia, most often in older children and young adults.

Fungal pneumonia : soil fungi or bird droppings can cause pneumonia in people who inhale large numbers of organisms. They can also cause pneumonia in people with chronic diseases or weakened immune systems .

A type of fungal pneumonia is called Pneumocystis jirovecii pneumonia (PCP). This condition usually affects people with weakened immune systems, such as those with AIDS .

In fact, PCP may be one of the first signs of AIDS infection.

Types by location

Pneumonia is also classified according to the place where it was acquired.

Pneumonia acquired in the hospital : this type of bacterial pneumonia is acquired during a hospitalization. It can be more serious than other types, because the bacteria involved may be more resistant to antibiotics.

Community-acquired pneumonia : refers to pneumonia that is acquired outside of a medical or institutional setting.

Types according to how they are acquired

Pneumonia can also be classified according to the way it is acquired.

Aspiration pneumonia : This type of pneumonia occurs when you inhale bacteria in the lungs from food, drink or saliva.

This type is more likely to occur if you have a problem swallowing or if it becomes too sedating due to the use of medications, alcohol or some types of illicit drugs.

Ventilator-associated pneumonia (VAP): When people who wear a respirator have pneumonia, it’s called VAP.

It is contagious?

Most types of pneumonia are contagious.

Both bacterial and viral pneumonia can spread to others through the inhalation of droplets in the air from a sneeze or cough.

But while it can become infected with fungal pneumonia from the environment, it does not spread from person to person.

Risk factor’s

Anyone can get pneumonia, but some people are at greater risk:

  • Babies from birth to 2 years of age and people 65 years of age or older.
  • People who have had a stroke, have problems swallowing or are bedridden.
  • People with weakened immune systems due to illness or use of medications such as steroids or certain drugs for cancer.
  • People who smoke, abuse certain types of illicit drugs or drink excessive amounts of alcohol.
  • People with certain chronic medical conditions such as asthma , cystic fibrosis, diabetes or heart failure.


Your doctor will start asking you questions about when your symptoms first appeared and about your medical history. They will also do a physical exam.

This will include listening to your lungs with a stethoscope to detect any abnormal sounds, such as cracking.

Your doctor may also order a chest x-ray. Usually, pneumonia can be diagnosed with a physical examination and a chest x-ray.

But depending on the severity of your symptoms and your risk of complications, your doctor may also order one or more of these tests:

A blood test: This test can confirm an infection, but may not be able to identify what is causing it.

A sputum test : This test can provide a sample of your lungs that can identify the cause of the infection.

Pulse Oximetry : An oxygen sensor placed on one of your fingers can indicate if your lungs are moving enough oxygen through your bloodstream.

A urine test : This test can identify the bacteria Streptococcus pneumoniae and Legionella pneumophila.

A CT scan: This test gives a clearer and more detailed picture of your lungs.

A sample of fluid : If your doctor suspects there is fluid in the pleural space of your chest, you can drink fluid with a needle placed between your ribs.

This test can help identify the cause of your infection.

Bronchoscopy : This test examines the airways of the lungs. It does so by using a camera on the end of a flexible tube that is gently guided down the throat to the lungs. Your doctor can perform this test if your initial symptoms are severe or if you are hospitalized and your body does not respond well to antibiotics.


Your treatment will depend on the type of pneumonia you have, how severe it is, and your general health.

Prescribed treatment

Antibiotics, antivirals and antifungals are used to treat pneumonia, depending on the specific cause of the disease.

Most cases of bacterial pneumonia can be treated at home with oral antibiotics, and most people respond to antibiotics in one to three days.

Your doctor may also recommend over-the-counter medications to relieve your pain and fever, as needed. These may include aspirin, ibuprofen (Advil, Motrin) and acetaminophen (Tylenol).

Your doctor may also recommend medications for coughs and rest. However, cough helps eliminate fluid from your lungs, so you do not want to eliminate it completely.

Treatment at home

It can help your recovery and prevent a recurrence:

  • Take your medications as prescribed.
  • Resting a lot.
  • Drinking lots of liquids
  • Do not exaggerate when you go back to school or work too soon.


If your symptoms are very severe or if you have other health problems, you may need to be hospitalized.

At the hospital, doctors can track your heart rate, temperature and breathing. The treatment may include:

Intravenous antibiotics : These are injected into your vein.

Respiratory therapy : This therapy uses a variety of techniques, which include administering specific medications directly into the lungs.

The respiratory therapist can also teach or help you perform breathing exercises to maximize your oxygenation.

Oxygen therapy : This treatment helps maintain the level of oxygen in the bloodstream.

You can receive oxygen through a nasal tube or a face mask. If your case is extreme, you may need a ventilator (a machine that supports breathing).