Pneumonia is an infection that inflames the air sacs of one or both lungs. The air sacs may fill with fluid or pus.

Pneumonia is caused by small germs, such as bacteria, viruses, and fungi. When life-threatening changes occur in the lungs, requiring a ventilator, there is fluid around the lung (pleural effusion) pneumonia is considered serious and can lead to death.
Most bacterial pneumonias clear up in 1 to 2 weeks. Walking pneumonia and viral pneumonia can take 4-6 weeks to clear up completely. The diagnosis of pneumonia usually requires a chest X-ray.
Viral pneumonias are considered to be of contagious origin and can be transmitted by airborne particles (through coughing or sneezing). It can also be spread by other fluids, such as blood at birth, or through contaminated surfaces.
Symptoms:
1. The most common symptom is chest pain which can be felt as squeezing pain, strong pressure or constrictive pain. The pain may radiate to the arm, shoulder, jaw, or back.
2. causes coughing up phlegm or pus,
3. fever, chills and shortness of breath.
The types of infection that pneumonia produces as the case may be:
1. Streptococcus pneumoniae is the most common cause of bacterial pneumonia in children.
2. Haemophilus influenzae type b (Hib) is the second most common cause of bacterial pneumonia.
3. Respiratory syncytial virus is the most common cause of viral pneumonia.
Treatments:
Pneumonia is usually treated with antibiotics, rest, and plenty of fluids. Antiviral medicines can be used to treat the flu. Fungal types of pneumonia are usually treated with antifungal medications.
The patient when he has pneumonia should avoid the following:
• Do not consume dairy products. symptoms may worsen.
• Do not eat cruciferous vegetables. Gas and bloating are uncomfortable, and these symptoms can make it difficult for people with lung disease to breathe.
• Do not eat fried food.
• Do not consume soft drinks.
• It is recommended:
• Take a balanced diet.
• Have a good rest.
• Perform appropriate physical activity for the person, which increases breathing.
• Mental health care.

https://medlineplus.gov/spanish/pneumonia.html
https://www.neumomadrid.org/wp-content/uploads/monogix_1._neumonias-concepto.pdf