Pneumonia is a lung infection that causes inflammation in the air sacs, known as alveoli, which can then fill with fluid or pus. While symptoms can vary among individuals, this illness often progresses through distinct stages. Each stage is marked by characteristic changes in both the lungs and the symptoms experienced. Understanding these stages can help in recognizing how the illness develops.
Early Symptoms of Congestion
The initial phase of pneumonia is called the congestion stage, occurring within the first 24 hours of infection. During this time, the lungs become heavy and engorged as fluid accumulates in the air sacs. This fluid buildup is an early response to the infection.
Patients in this stage experience symptoms. A cough is present, often dry at first, but it can also produce clear, yellow, or green sputum. Fever and chills are common, alongside fatigue and muscle aches. Individuals may also notice shortness of breath and a feeling of heaviness or pressure in the chest.
Symptoms During Red Hepatization
Following the congestion phase, symptoms intensify during the red hepatization stage, which occurs within 48 to 72 hours of infection and can last for two to four days. This stage is characterized by the consolidation of lung tissue, as red blood cells, fibrin, and white blood cells accumulate within the alveoli. The affected lung tissue can appear reddish and firm, resembling the texture of a liver, which is where the term “hepatization” originates.
The cough becomes more severe and productive during this stage, yielding rust-colored sputum due to the presence of blood. Chest pain, often sharp with breathing or coughing, is common. Fever may remain high or even increase, and individuals experience severe shortness of breath, severe fatigue, and muscle aches. Lips or nail beds may develop a bluish tint due to reduced oxygen levels.
Symptoms During Grey Hepatization
The red hepatization phase transitions into the grey hepatization stage, appearing around day four to six and lasting for several days. In this phase, the accumulated red blood cells within the lung exudate begin to break down, and fibrin continues to build up, giving the lung tissue a grayish or yellowish appearance. While the lung still maintains a firm consistency, the acute inflammatory response starts to subside.
The cough may remain productive, but the sputum changes from rusty to a clearer or yellowish color as the red blood cells diminish. The fever begins to subside, and chest pain lessens, signaling a decrease in the acute inflammation. Breathing can still be labored, though it feels less severe than during the red hepatization phase, as the body moves towards recovery.
Symptoms of Resolution
The final stage of pneumonia is resolution, where the body works to clear the infection and repair the lung tissue, beginning around day eight to ten. During this phase, the fluid and cellular debris that filled the alveoli are enzymatically digested and reabsorbed by the body or coughed up. The lung tissue gradually returns to its normal state and function.
Patients experience a noticeable improvement in their symptoms during resolution. The cough diminishes, breathing becomes easier, and body temperature returns to normal. Energy levels increase, and there is improved well-being. While the acute symptoms resolve, some individuals may experience a lingering cough or fatigue for weeks as the body recovers and clears any remaining debris.