A condition resulting from infection in one or both lungs.

A severe inflammation of the lungs in which the alveoli (tiny air sacs) are filled with fluid. This may cause a decrease in the amount of oxygen that blood can absorb from air breathed into the lung. Pneumonia is usually caused by infection but may also be caused by radiation therapy, allergy, or irritation of lung tissue by inhaled substances. It may involve part or all of the lungs.

An acute and/or chronic inflammation focally or diffusely affecting the lung parenchyma.

An acute, acute and chronic, or chronic inflammation focally or diffusely affecting the lung parenchyma, due to infections (viruses, fungi, mycoplasma, or bacteria), treatment (e.g. radiation), or exposure (inhalation) to chemicals. Symptoms include cough, shortness of breath, fevers, chills, chest pain, headache, sweating, and weakness.

Infection of the lung often accompanied by inflammation.

Inflammation of any part of the lung parenchyma.

Inflammation of the lungs with consolidation and exudation.

Pneumonia is an infection in one or both of the lungs. It causes the air sacs of the lungs to fill up with fluid or pus. It can range from mild to severe, depending on the type of germ causing the infection, your age, and your overall health. Bacterial, viral, and fungal infections can cause pneumonia. Bacteria are the most common cause. Bacterial pneumonia can occur on its own. It can also develop after you've had certain viral infections such as a cold or the flu. Several different types of bacteria can cause pneumonia, including: Streptococcus pneumoniae; Legionella pneumophila; this pneumonia is often called Legionnaires' disease; Mycoplasma pneumoniae; Chlamydia pneumoniae; Haemophilus influenzae. Viruses that infect the respiratory tract may cause pneumonia. Viral pneumonia is often mild and goes away on its own within a few weeks. But sometimes it is serious enough that you need to get treatment in a hospital. If you have viral pneumonia, you are at risk of also getting bacterial pneumonia. The different viruses that can cause pneumonia include: Respiratory syncytial virus (RSV); Some common cold and flu viruses; SARS-CoV-2, the virus that causes COVID-19. Fungal pneumonia is more common in people who have chronic health problems or weakened immune systems. Some of the types include: Pneumocystis pneumonia (PCP); Coccidioidomycosis, which causes valley fever; Histoplasmosis; Cryptococcus. Anyone can get pneumonia, but certain factors can increase your risk: Age; the risk is higher for children who are age 2 and under and adults age 65 and older; Exposure to certain chemicals, pollutants, or toxic fumes; Lifestyle habits, such as smoking, heavy alcohol use, and malnourishment; Being in a hospital, especially if you are in the ICU. Being sedated and/or on a ventilator raises the risk even more.; Having a lung disease; Having a weakened immune system; Have trouble coughing or swallowing, from a stroke or other condition; Recently being sick with a cold or the flu. The symptoms of pneumonia can range from mild to severe and include: Fever; Chills; Cough, usually with phlegm (a slimy substance from deep in your lungs); Shortness of breath; Chest pain when you breathe or cough; Nausea and/or vomiting; Diarrhea. The symptoms can vary for different groups. Newborns and infants may not show any signs of the infection. Others may vomit and have a fever and cough. They might seem sick, with no energy, or be restless. Older adults and people who have serious illnesses or weak immune systems may have fewer and milder symptoms. They may even have a lower than normal temperature. Older adults who have pneumonia sometimes have sudden changes in mental awareness. Sometimes pneumonia can cause serious complications such as: Bacteremia, which happens when the bacteria move into the bloodstream. It is serious and can lead to septic...

Pneumonia is acute inflammation of the lungs caused by infection. Initial diagnosis is usually based on chest x-ray and clinical findings. Causes, symptoms, treatment, preventive measures, and prognosis differ depending on whether the infection is bacterial, mycobacterial, viral, fungal, or parasitic; whether it is acquired in the...

Pneumonia is an infection that inflames the air sacs in one or both lungs. The air sacs may fill with fluid or pus (purulent material), causing cough with phlegm or pus, fever, chills, and difficulty breathing. A variety of organisms, including bacteria, viruses and fungi, can cause pneumonia.

Pneumonia, inflammation and consolidation of the lung tissue as a result of infection, inhalation of foreign particles, or irradiation. Many organisms, including viruses and fungi, can cause pneumonia, but the most common causes are bacteria, in particular species of Streptococcus and Mycoplasma....