Pneumonia: Symptoms, Types, Causes and Treatment.


Pneumonia is a lung infection that can be mild or severe enough that you have to go to the hospital. It causes an infection that inflames the alveoli (air sacs) in one or both lungs. These air sacs will be filled with fluid or pus, causing cough (with pus), fever, and chills. This can make it difficult for you to breathe-in enough oxygen to reach your bloodstream. Organisms like bacteria, viruses, and fungi, can cause pneumonia. Lung infection can occur in anyone mostly infants younger than age 2 years and people older age 65years. This is because their immune systems are not strong enough to fight infection. Pneumonia with a bacterial or viral origin can be spread easily to someone else. Lifestyle habits, like cigarette smoking and excess alcohol intake, can also raise your chances of getting pneumonia.

3 Major types of pneumonia


The most common cause of bacterial pneumonia is Streptococcus pneumoniae. Some other causes are: Mycoplasma pneumoniae, Haemophilus influenzae, and Legionella pneumophila

Bacterial Pneumonia can be transmitted from one person to another through sneezing and coughing. These bacteria-filled droplets get into the air and healthy people inhale them, causing infection. Also, the risk is higher for people with a weak immune system.

Some symptoms include

  • Fever of 102-105°F or above
  • Cough with thick yellow, green, or blood-tinged sputum
  • Chest pain that worsens when coughing or breathing
  • Sudden onset of chills severe enough to make you shake
  • Headache
  • Muscle pain
  • Tiredness or fatigue
  • Confusion (especially among older folks).

For bacterial causes of pneumonia, Antibiotics are prescribed.

Some classes of bacterial pneumonia are: 

a. Hospital-acquired pneumonia (HAP):   This is usually gotten from staying in the hospital with at least 46-72 hours of admission. It could be serious because most of the bacteria causing this are resistant to antibiotics. It is usually seen in patients on:

  • Ventilators (breathing machine)
  • Patients who can’t cough properly to clear mucus from the lungs.

b. Walking pneumonia: Is a less severe form of bacterial pneumonia. You feel well enough to carry out your daily activities which is why it is called “walking pneumonia”. Sometimes, doctors call it “atypical” pneumonia.  It spreads through sneezes or coughs but it spreads slowly.

 Some causes include Mycoplasma pneumonia, chlamydophilia pneumonia, and Legionella pneumophilia.
 Walking pneumonia from mycoplasma is most common in children, military recruits, and adults younger than 40years. People living in crowded places like dorms, military barracks, and nursing homes can easily contract it. It is most common in Late summer and fall.


Antibiotics treat the infection. You will most likely begin to feel better between 3 to 5 days, but the cough can last a few weeks.

c. Community-Acquired Pneumonia (CAP)CAP occurs outside the hospital and health care facilities. It is the most common type of pneumonia and affect people of all ages.

It can be caused by bacteria, fungi or viruses. Streptococcus pneumoniae is the most common bacterial cause Some other common bacteria that cause CAP are:

Haemophilus influenzae, and some atypical bacterias like Mycoplasma pneumoniae, Chlamydia pneumonia, Legionella. The most common virus causing CAP is influenza.

Aspiration pneumonia

Aspiration pneumonia happens when you inhale food particles, fluids, or vomitus into the lungs. It most likely occurs if something disturbs your normal gag reflex. For example, excessive use of alcohol, brain injury, or a problem with swallowing.

They are mostly due to anaerobic organisms like are Bacteroides, fusobacterium or peptostreptococcus.

Some symptoms include

  • Chest pain
  • Shortness of breath/ difficulty breathing
  • Bad breath
  • Wheezing.
  • Cyanosis
  • Cough, producing greenish, bloody, or foul-smelling sputum.
  • Excessive sweating.


Viruses are the most common cause of Pneumonia. Some of these include: Influenza (flu), Respiratory Syncytial Virus (RSV), Rhinoviruses (common cold), and Coronavirus (COVID-19 or SARS).

Viral pneumonia is milder and usually improve within one to three weeks without treatment.

Some symptoms include:

  • Fever
  • Dry cough
  • Shortness of breath
  • Chills
  • Chest pain associated with coughing or breathing
  • Fast breathing
If you have a new onset of shortness of breath, fever, cough, see your doctor.

Your Doctor might recommend Drinking extra fluids to help loosen mucus in your chest. Also, acetaminophen or a non-steroidal anti-inflammatory drug (NSAID) like ibuprofen can be given to relieve pain and fever. If it is due to the flu virus (influenza), drug such as oseltamivir (Tamiflu®), zanamivir (Relenza®), etc may be recommended. This will help to decrease the length and severity of the illness and also help you breathe better.


Fungal pneumonia is rare. However, it most commonly affects people with a weak immune system such as organ transplant patients, cancer patients on chemotherapy, and HIV patients as well as people working in certain jobs like:

  • Farmers who come in contact with bird, bat, or rodent droppings
  • Also, those who work with the soil such as Gardners and landscapers
  • Construction workers who are around a lot of dust.

Some examples include

  • Pneumocystis jirovecii(usually in organ transplant patients, HIV patients, and patients with autoimmune diseases),
  • Candidiasis has pulmonary manifestations in immunocompromised patients
  • Cryptococcus species, and
  • Histoplasmosis species.
  • Blastomycosis..

Pneumonia in newborns and infants can be harder to notice. They may present with:

  • Rapid breathing
  • Difficulty breathing
  • Restlessness, tiredness
  • Difficulty feeding
  • Vomiting
  • Fever
  • Cough, wheezing
  • Cyanosis (bluish discoloration of the skin, lips, or fingers)


To help prevent pneumonia:

1. Get vaccinated

2. Make sure children get vaccinated.

3. Practice good hygiene: Wash your hands regularly or use an alcohol-based hand sanitizer.

4. Don’t smoke. Smoking damages the natural defenses in your lungs

5. Keep your immune system strong: Sleep well, exercise regularly, and eat a healthy diet.

6. Cover your mouth with a tissue or your sleeve when you cough or sneeze

7. Try not to touch your eyes, ears, nose, and mouth.