The first stage is congestion and it happens between one and two days, this is where the blood vessels and alveoli start filling with excess fluid. The next stage is red hepatization and it happens between days three and four, this is where exudate which contains red blood cells neutrophils and fibrin starts filling the air spaces and makes them more solid, the name hepatization refers to the lungs taking on a liver-like appearance from the reddish-brown color of the exudate. Third stage is gray hepatization which happens around days five to seven, in this stage, the lungs are still firm but the colors change, because the red blood cells in the exudate are starting to break down. The last stage is called resolution and this happens around day eight and can continue for three weeks. In this stage, the exudate gets digested by enzymes ingested by macrophages or coughed up pneumonia most often causes dyspnea or shortness of breath as well as chest pain and a productive cough meaning that pus or bloody sputum might come up, often there are also systemic symptoms like fatigue and fever diagnosis of pneumonia is usually made in a person who’s working hard to breathe or breathing quickly. A chest x-ray of bronchopneumonia typically shows patchy areas that are spread out throughout the lung in atypical or interstitial pneumonia, the pattern is also often spread throughout the lungs but it’s often concentrated in the perihylar region and looks reticular, meaning there will be more line shaped opacities visible in the chest x-ray in a low bar.
Pneumonia fluids localized to a single lobe or set of lobes another way to detect lobar pneumonia though is to look for dullness to percussion which suggests that there’s lung consolidation, there’s also tactile vocal feminists which is when you can feel more vibrations from a person’s chest or back after they repeat certain phrases, this is because sound travels better through the fluid-filled consolidated tissue than air-filled healthy tissue, late inspiratory crackles might also be heard along with bronchial breath sounds. Bronchophony and egophony, the treatment of pneumonia depends on the type and severity of pneumonia since bacteria are the most likely cause, antibiotics are often prescribed in addition, cough suppressants and pain medications are often used to help with symptoms.
So as a quick recap, pneumonia is an infection of the lungs that results in air sacs being filled with fluid, the disease can be classified by being either community acquired, hospital acquired, with some of those being ventilator-associated pneumonias or aspiration pneumonias. Pneumonia can also be characterized by where the infection is in the lungs. Bronchopneumonia is spread throughout the lungs atypical or interstitial, pneumonia happens in the interstitium around the alveoli and lobar pneumonia usually infects an entire lobe of the lung.