What Are The 4 Stages Of Pneumonia?

What Are The 4 Stages Of Pneumonia?

Jan 01, 2022

Pneumonia – the word itself might bring to mind images of hospital stays and medical treatments, but what goes on in our bodies when we catch this common lung infection? Pneumonia is a lung infection in the basic respiratory unit where air exchange happens- the alveoli get filled with pus and fluid, leading to difficulty breathing and poor oxygen intake. The infection often progresses through four stages, each characterized by its peculiar nature and symptoms. This article will discuss the condition and its progression through these stages and remedies.

symptoms of pneumonia

View Larger

Types of Pneumonia

  • Lobar Pneumonia: Lobar pneumonia is a type of pneumonia that affects a large and continuous area of a lung lobe. Its systematic progression characterizes it through four stages: congestion, red hepatization, grey hepatization, and resolution. This pneumonia is often caused by bacterial infection and can lead to severe lung inflammation.
  • Walking Pneumonia: Walking pneumonia, a milder form, is called “walking” pneumonia because individuals with this type typically aren’t bedridden and can continue their daily activities. Symptoms of walking pneumonia include a persistent dry cough, sore throat, fatigue, and sometimes a low-grade fever. Due to its subtlety, it’s often mistaken for a common cold.
  • Fungal Pneumonia: Fungal pneumonia arises from a fungal infection in the lungs. It’s less common and usually affects individuals with weakened immune systems, such as those with HIV/AIDS or cancer or those taking immunosuppressive drugs. The symptoms are similar to other types of pneumonia but can be more severe and require specialized antifungal treatment.
  • Viral Pneumonia: Viral pneumonia is caused by various viruses, including the influenza virus and respiratory syncytial virus (RSV). It’s typically milder than bacterial pneumonia but can be severe in older adults, children, and those with weakened immune systems. Symptoms include dry cough, fever, and shortness of breath.
  • Bacterial Pneumonia: Bacterial pneumonia is caused by bacteria. It can affect one or both lungs, and symptoms include a cough with phlegm, fever, chills, and difficulty breathing. Antibiotics are the mainstay of treatment for bacterial pneumonia.
  • Community-Acquired Pneumonia (CAP): CAP is pneumonia acquired outside hospitals or other healthcare facilities. It’s the most common type of pneumonia and can be caused by bacteria, viruses, or fungi. Symptoms are similar to other pneumonias, but treatment depends on the specific cause and severity.
  • Chemical Pneumonia: Chemical pneumonia results from breathing in toxic chemicals, which cause lung inflammation. The symptoms can vary based on the inhaled chemical, ranging from mild respiratory irritation to severe respiratory distress. Treatment involves removing the source of exposure and supportive care.
  • Aspiration Pneumonia: Aspiration pneumonia occurs when food, saliva, liquids, or vomit are breathed into the lungs or airways leading to the lungs rather than being swallowed into the esophagus. It’s more common in individuals with conditions that affect normal gag reflex or swallowing. Symptoms include cough, bad breath, fever, and a crackling sound while breathing. Treatment typically involves antibiotics and supportive care.

What Are The Causes Of Pneumonia?

Bacteria, viruses, and fungi are the microbes responsible for causing pneumonia. They are primarily spread from person to person via the inhalation of droplets from sneezing or coughing, the typical pattern for respiratory infections. However, fungal pneumonia is spread via contact with the environment, which is more common in people with compromised immunity.

Doctors also classify the causes of pneumonia based on where the infection was gotten. These classifications include hospital-acquired, community-acquired, ventilator-associated pneumonia, and others.

What Are The Risk Factors For Acquiring Pneumonia?

Although anyone can get infected with pneumonia, specific populations are more at risk. Pneumonia is one of the leading causes of death in children under five years. Parents should always seek emergency care treatment at a walk-in clinic when children show signs of a respiratory infection like cough, catarrh, fever, and irregular breaths. Older adults above 65 years are also at increased risk.

Other risk factors include reduced immunity seen in pregnancy, HIV and chemotherapy, chronic conditions like asthma, diabetes, heart failure, lifestyle factors like alcohol, smoking, and overcrowding.

Four Stages Of Pneumonia

  • Stage 1 – Congestion

The first stage of pneumonia falls mainly into the first 24 hours after the infection. A cough with clear or green/yellow sputum, high fever and chills, chest heaviness, and chest pain with breathing often characterize it. Some people also complain of headaches, loss of appetite, nausea, and vomiting accompanied by rapid breaths. Please visit our ER near you, Ascent Emergency Room, if you notice any of these symptoms. At this stage, a prompt diagnosis and corresponding early treatment are crucial.

  • Stage 2 – Red Hepatization

In the next few days after infection, pneumonia worsens. This stage comes with a cough that produces thicker and more copious sputum. It may even be tinged with blood. Shortness of breath can appear here, and the lips and fingers may turn blue due to low blood oxygen levels. There’s also marked fatigue that may lead to delirium in older adults. At our emergency room in Houston, we institute antibiotic therapy at this stage if it had not been done earlier. Another peculiar feature of this stage is that complications are first seen here. The bacteria in the lungs can spread anywhere in the body, causing further infection in the brain, heart valves, joints, kidneys, spleen, and other parts.

  • Stage 3 – Grey Hepatization

The features seen in the third stage are either signs of improvement or a worsening condition. If the infection is caught earlier and adequately treated, the symptoms can start to resolve. Otherwise, there’s increased breathing difficulty, and older people may start coughing blood. This will come with worse complications (such as a lung abscess and bleeding into the lungs), and some people may need to be placed on oxygen at this stage.

  • Stage 4 – Resolution

The infection is resolved with proper treatment at the last stage of pneumonia. The microbes are killed off, and the immune cells work to clear up all signs of the infection. However, failure to treat or poor treatment will lead to far worse complications, and death is possible.

How Can You Prevent Pneumonia?

First, get vaccinated. Several vaccines protect against pneumonia in different age groups. Try to avoid smoking cigarettes and alcohol intake as they increase the risk of pneumonia. Maintaining good hygiene by washing your hands regularly with soap and water is good. Lastly, always seek emergency help for symptoms of a respiratory infection.


What are the stages of pneumonia?

There are generally three stages of pneumonia:

  • a) Early-stage or community-acquired pneumonia
  • b) Consolidation stage
  • c) Resolution stage

What are the symptoms of early-stage pneumonia?

In the early stage, symptoms may include:

  1. Cough with or without phlegm
  2. Low grade fever
  3. Fatigue and weakness
  4. Shortness of breath

What characterizes the consolidation stage of pneumonia?

During consolidation, symptoms worsen and may include:

  1. High fever
  2. Persistent cough with green or yellow mucus
  3. Increased difficulty breathing
  4. Chest pain, especially during coughing or deep breaths

What happens during the resolution stage of pneumonia?

The resolution stage involves the gradual improvement of symptoms, such as:

  1. Reduced fever
  2. Lessening of cough and mucus production
  3. Regaining energy and strength
  4. Continued mild weakness or fatigue

Can pneumonia symptoms vary depending on the cause?

Yes, the symptoms can differ based on the cause of pneumonia, which may be viral, bacterial, fungal, or other pathogens. Some variations include dry cough in viral pneumonia and severe symptoms in bacterial pneumonia.

Are there additional symptoms to watch out for in severe pneumonia?

Yes, severe pneumonia may exhibit alarming symptoms like:

  • High fever (above 102°F or 39°C)
  • Rapid and shallow breathing
  • Bluish lips or fingertips (cyanosis)
  • Confusion or altered mental state

When should I seek medical attention for pneumonia symptoms?

You should get immediate medical attention if you experience:

  1. Difficulty breathing or shortness of breath
  2. Severe chest pain
  3. Persistent high fever
  4. Confusion or disorientation

How is pneumonia diagnosed?

Pneumonia is diagnosed through a combination of:

  1. Physical examination
  2. Chest X-ray or CT scan
  3. Sputum analysis
  4. Blood tests

Can pneumonia be prevented?

Yes, certain measures can lower the risk of pneumonia:

  1. Vaccination (e.g., pneumococcal and influenza vaccines)
  2. Handwashing and good hygiene practices
  3. Avoiding smoking and secondhand smoke

What is the typical recovery time for pneumonia?

Recovery times fluctuate depending on the severity of pneumonia and individual health. Generally, it may take one to three weeks for most people to recover fully under the treatment & recommendation of an emergency room. However, it can be longer for older adults or those with weakened immune systems.

Are you looking for an emergency room in Houston, TX? At Ascent Emergency Room, we care about your health and their emergency needs. We are located just a little away from you and provide exceptional and comprehensive emergency care appointments for the surrounding Houston area:

  • (Southampton) University Place
  • Rice Village
  • Bellaire
  • Old Braeswood
  • Gridiron
  • Brookhaven
  • Southside
  • Riverside Terrace
  • Greater Third Ward
  • Greater Eastwood
  • East Downtown
  • Midtown
  • Montrose
  • Westmoreland Houston
Call Now Check-In Online
Click to listen highlighted text!