Types of pneumonia and symptoms

Over the last 15 years, I have personally treated thousands of patients with different types of pneumonia. I would like to review different types of pneumonia and their symptoms here. I have also written several other articles on different aspects of pneumonia. You can find those on “Diseases and Conditions” page.

What are the different types of pneumonia and their symptoms?

Pneumonia is a broad category of diseases. Any infection of the lungs is called pneumonia. Pneumonia can be separated into different types based on the parts of the lungs or based on the cause of the pneumonia. Symptoms of pneumonia not only depend on the type of the pneumonia but also depend on the severity of the pneumonia. It also depends on the age and pre-existing health conditions of the patient. 

Types of pneumonia based on causative agents and their symptoms 

There are 4 major types of pneumonia based on what caused them:

  • Bacterial pneumonia
  • Viral Pneumonia
  • Atypical Pneumonia (also called walking pneumonia)
  • Fungal pneumonia

Bacterial pneumonia and their symptoms

Bacterial pneumonia is the most commonly diagnosed type of pneumonia. When people talk about pneumonia in general without specifying the type of pneumonia, they are talking about bacterial pneumonia. Symptoms of bacterial pneumonia may vary from very mild, hard-to-detect symptoms to life-threatening severe symptoms requiring hospitalization. We will look at the specific symptoms in specific situations. Please look for the possible symptoms based on which of the following situations apply to you.

Bacterial pneumonia may also be divided into two types based on where you caught the pneumonia:

  • Community acquired bacterial pneumonia
  • Hospital acquired bacterial pneumonia

Mild bacterial community acquired pneumonia symptoms in otherwise healthy adults

If you are in good health when you catch pneumonia, you may only have mild symptoms. You may have one or more of the following symptoms:

  • Mild fevers and chills
  • Mild cough
  • Phlegm production
  • Body aches
  • Chest pain or tightness with breathing

Severe bacterial community acquired pneumonia symptoms in otherwise healthy adults

Even healthy adults can sometimes have symptoms of severe bacterial pneumonia. Patients with severe bacterial pneumonia symptoms may need hospitalization. If you want to learn more about when you need hospitalization for pneumonia and what to expect when you are admitted to the hospital with pneumonia, you can read “Hospitalized for pneumonia.”

Here are the symptoms of severe bacterial pneumonia in healthy adults:

  • High fevers associated with shaking chills and rigors
  • Increased coughs
  • Sharp chest pains with coughs and deep breaths
  • Feeling weak and dizzy
  • Some shortness of breath

Severe bacterial community acquired pneumonia symptoms in the elderly and those with pre-existing health problems

The elderly and those with underlying heart or lung problems are at risk of getting severe life threatening symptoms from bacterial pneumonia. Most of the patients in this category will need hospitalization for their pneumonia.

Here are the symptoms of severe bacterial pneumonia in the elderly and sick patients:

  • Confusion
  • Lethargy
  • Falls
  • Severe generalized weakness
  • High fevers and chills
  • Severe shortness of breath
  • Low blood pressures
  • Fainting and collapsing

Hospital acquired bacterial pneumonia symptoms

Hospital acquired bacterial pneumonia symptoms differ significantly from community acquired bacterial pneumonia symptoms. Hospital acquired pneumonia may happen to patients who are hospitalized or who were recently hospitalized and discharged home. Hospital acquired pneumonia may happen without the usual symptoms of coughs and a fever.

Here are some of the signs and symptoms that could point to the possibility of hospital acquired pneumonia:

  • Confusion and disorientation
  • Hallucinations and delirium
  • High fevers and chills without any other symptoms
  • Severe fatingue
  • Worsening shortness of breath
  • Needing more oxygen treatment than he or she is already getting
  • Abnormal lab values
  • Low blood pressures

Viral pneumonia and their symptoms

There are many types of viral pneumonia that are very different from each other based on the type of virus that is causing the pneumonia. It can be very mild with symptoms similar to the common cold when caused by a common respiratory virus. On the other extreme, it can lead to respiratory failure and death when caused by a pandemic virus such as the Novel Coronavirus 2019 that causes COVID-19. COVID-19 is a form of viral pneumonia that can be fatal. It is not possible to describe the symptoms of all types of viral pneumonia but I will try to put them in 3 different categories to help understand them a little bit better.

Here are the three broad categories of viral pneumonia symptoms:

  • Viral pneumonia symptoms caused by common respiratory viruses
  • Viral pneumonia symptoms caused by flu related viruses
  • Viral pneumonia symptoms leading to severe acute respiratory syndrome caused by pandemic and new viruses

Viral pneumonia symptoms caused by common respiratory viruses

Mild viral pneumonia symptoms are caused by viruses that are related to and similar to the common cold virus. Most patients with the common viral pneumonia may not even know they had it. They may recover on their own without even seeking medical help.

Here are some of the symptoms you can expect from common viral pneumonia:

  • Dry cough
  • Mild fever
  • Body aches
  • Mild pains or discomfort in the chest

Viral pneumonia symptoms caused by flu viruses

There are several different types of influenza viruses that cause the flu. Viral pneumonia can be a part of the flu syndrome. Not all patients infected with the flu viruses get pneumonia. Viral pneumonia caused by flu viruses can range from a mild illness to severe life-threatening disease. Similar to bacterial pneumonia, older people with pre-existing heart or lung problems are at higher risks of developing severe symptoms from an influenza virus infection.

Here are some of the milder symptoms caused by an influenza-type viral pneumonia:

  • Dry cough
  • Fevers and chills
  • Chest tightness and pain with breathing
  • Body aches
  • Feeling tired

Here are some of the more severe symptoms of viral pneumonia caused by flu viruses:

  • High fevers and chills
  • Shortness of breath and chest pain
  • Dizziness or lightheadedness
  • Severe body aches
  • Fatigue
  • Confusion and disorientation
  • Fast and swallow breathing

Some patients with severe viral pneumonia from the flu will need hospitalization. Some patients initially diagnosed with influenza viral pneumonia may later develop bacterial pneumonia. Those patients have symptoms similar to what I described under “severe bacterial pneumonia.”

Atypical pneumonia and their symptoms

Atypical pneumonia is a term that included pneumonia caused by several different organisms. The most of these is a bacterium called Mycoplasma. Mycoplasma pneumonia is also called walking pneumonia because most patients have only mild symptoms. They could even be unaware that they have pneumonia.

Here are some of the common symptoms of walking pneumonia:

  • Dry cough
  • Sore throat
  • Fever
  • Hoarse voice
  • Headaches

Fungal pneumonia

Fungal pneumonia is the least common type of pneumonia. It is caused by many different kinds of fungi. Fungal pneumonia is somewhat difficult to diagnose.

Fungal pneumonia and their symptoms can be broadly divided into two different types:

  • Opportunistic fungal pneumonia
  • Fungal pneumonia associated with specific exposure

Opportunistic fungal pneumonia symptoms

Like the name suggests, opportunistic infections occur when certain fungi find the perfect opportunity to cause invasive diseases in specific patients. These fungi can only infect and invade the lungs of those people whose immune systems have been compromised. In healthy people with a good immune system, these fungi are killed before they can cause problems.

Here are people that are at increased risks of getting opportunistic fungal infections:

  • People getting chemotherapy for cancer
  • People with an untreated HIV infection
  • People getting immune-suppressing medication after organ transplant
  • People getting high-dose steroids
  • Anyone with a decreased immune response related to any other cause

Here are the possible signs and symptoms of opportunistic fungal pneumonia:

  • Unexplained shortness of breath
  • Fever of unknown origin
  • Chest pain when breathing
  • Coughing up blood
  • Wheezing and chest tightness

Fungal pneumonia associated with specific exposures

These fungi can cause pneumonia in otherwise healthy people with good immune systems. Luckily, these fungi are only found in certain places.

We need to suspect the possibility of fungal pneumonia in patients who are exposed to these certain environments:

  • Places littered with feces of infected bats
  • Places with dried bird poop everywhere
  • Dusty caves
  • Moldy places with poor ventilation

Anyone with a recent visit to any of those places needs to look out for symptoms of exposure associated with fungal pneumonia, including:

  • Fever
  • Dry cough
  • Blood-tinged phlegm
  • Weight loss
  • Chest pain with a cough or deep breaths
A chart showing types and subtypes of pneumonia
Types and subtypes of pneumonia

Different types of pneumonia and their symptoms based on the parts of the lungs involved

Symptoms of pneumonia may differ slightly based on what parts of the lungs are involved. Our lungs have large air pipes, smaller air pipes, and even smaller air pipes that end in air sacs. The air sacs are where the air exchange takes place. In addition to the air sacs and air tubes, there are also connective tissues that hold the whole lung together. Certain types of pneumonia involve certain parts of the lungs.

Here are the types of pneumonia and their symptoms based on the parts of the lungs involved:

  • Lobar pneumonia
  • Interstitial pneumonia
  • Bronchopneumonia
  • Double pneumonia

Lobar pneumonia symptoms

Lobar pneumonia is usually caused by common bacteria that are responsible for most of the bacterial pneumonia in adults. Please refer to bacterial pneumonia for the symptoms of lobar pneumonia.

Interstitial pneumonia symptoms

Interstitial pneumonia mostly involves the connective tissue in between the air sacs and air tubes. An example of interstitial pneumonia is the Mycoplasma pneumonia, or walking pneumonia. Mycoplasma pneumonia has mild symptoms as we discussed earlier. However, there are other types of interstitial pneumonia that may involve the lining of the air sacs and interfere with air exchange. Luckily, those types of interstitial pneumonia are relatively rarer than walking pneumonia.

Bronchopneumonia symptoms

Bronchopneumonia involves the smallest of the air tubes inside the lungs. The most common symptom of bronchopneumonia is a cough with lots of thick yellow phlegm.

Double pneumonia symptoms

When bacterial lobar pneumonia affects both sides of the lungs, it is called double pneumonia. The symptoms of double pneumonia are almost identical to lobar bacterial pneumonia. The difference is mainly noticed when looking at the x-ray of the person with double pneumonia.

In conclusion, pneumonia is a very broad category of disease and includes many types and subtypes that are differentiated based on cause, location, and severity. Pneumonia symptoms also depend on the age and health of the patient with pneumonia. I have summarized the classification of pneumonia in the figure below. Do not forget to view other articles on pneumonia if you would like more information.