2026 ICD-10-CM Diagnosis Code J18.9Pneumonia, unspecified organism

AHRQ’s CCSR groups this code into broader clinical categories.

• Bronchopneumonia

  inflammation of the lung parenchyma that is associated with bronchitis, usually involving lobular areas from terminal bronchioles to the pulmonary alveoli. the affected areas become filled with exudate that forms consolidated patches.

• Chlamydial Pneumonia

  pneumonia caused by infections with the genus chlamydia; and chlamydophila, usually with chlamydophila pneumoniae.

• Community-Acquired Pneumonia

  infection of the lungs in a patient who is not hospitalized or who has not resided in a long-term care facility for 14 days prior to the onset of symptoms. it is associated with some signs and symptoms of acute infection and is accompanied by the presence of an acute infiltrate on chest radiograph.(us pharm. 2007;32(10):44-5 https://www.uspharmacist.com/article/community-acquired-pneumonia)

• Cryptogenic Organizing Pneumonia

  an interstitial lung disease of unknown etiology, occurring between 21-80 years of age. it is characterized by a dramatic onset of a pneumonia-like illness with cough, fever, malaise, fatigue, and weight loss. pathological features include prominent interstitial inflammation without collagen fibrosis, diffuse fibroblastic foci, and no microscopic honeycomb change. there is excessive proliferation of granulation tissue within small airways and alveolar ducts.

• Hamman-Rich Syndrome

  acute idiopathic interstitial pneumonitis characterized by diffuse pulmonary alveoli damage with uniform edematous connective tissue proliferation. it is often associated with extensive fibroblastic distortion of the lung parenchyma and leads to adult respiratory distress syndrome in later stages.

• Healthcare-Associated Pneumonia

  infection of the lung often accompanied by inflammation that is acquired through an interaction within a healthcare institution often through a therapeutic experience (e.g., use of catheters or ventilators).

• Idiopathic Interstitial Pneumonias

  a group of interstitial lung diseases with no known etiology. there are several entities with varying patterns of inflammation and fibrosis. they are classified by their distinct clinical-radiological-pathological features and prognosis. they include idiopathic pulmonary fibrosis; cryptogenic organizing pneumonia; and others.

• Lung Diseases, Interstitial

  a diverse group of lung diseases that affect the lung parenchyma. they are characterized by an initial inflammation of pulmonary alveoli that extends to the interstitium and beyond leading to diffuse pulmonary fibrosis. interstitial lung diseases are classified by their etiology (known or unknown causes), and radiological-pathological features.

• Murine pneumonia virus

  a species of the genus pneumovirus causing pneumonia in mice.

• Organizing Pneumonia

  any obstructive lung disease characterized by consolidated formation of granulation tissue polyps within alveolar ducts and alveoli. it is classified as either primary (cryptogenic organizing pneumonia) or secondary organizing pneumonia. secondary organizing pneumonia after transplantation is called bronchiolitis obliterans syndrome.

• Pneumonia

  infection of the lung often accompanied by inflammation.

• Pneumonia of Calves, Enzootic

  chronic endemic respiratory disease of dairy calves and an important component of bovine respiratory disease complex. it primarily affects calves up to six months of age and the etiology is multifactorial. stress plus a primary viral infection is followed by a secondary bacterial infection. the latter is most commonly associated with pasteurella multocida producing a purulent bronchopneumonia. sometimes present are mannheimia haemolytica; haemophilus somnus and mycoplasma species.

• Pneumonia of Swine, Mycoplasmal

  a chronic, clinically mild, infectious pneumonia of pigs caused by mycoplasma hyopneumoniae. ninety percent of swine herds worldwide are infected with this economically costly disease that primarily affects animals aged two to six months old. the disease can be associated with porcine respiratory disease complex. pasteurella multocida is often found as a secondary infection.

• Pneumonia, Aspiration

  a type of lung inflammation resulting from the aspiration of food, liquid, or gastric contents into the upper respiratory tract.

• Pneumonia, Atypical Interstitial, of Cattle

  a cattle disease of uncertain cause, probably an allergic reaction.

• Pneumonia, Bacterial

  inflammation of the lung parenchyma that is caused by bacterial infections.

• Pneumonia, Lipid

  pneumonia due to aspiration or inhalation of various oily or fatty substances or otherwise accumulation of endogenous lipid substances in the pulmonary alveoli.

• Pneumonia, Mycoplasma

  interstitial pneumonia caused by extensive infection of the lungs (lung) and bronchi, particularly the lower lobes of the lungs, by mycoplasma pneumoniae in humans. in sheep, it is caused by mycoplasma ovipneumoniae. in cattle, it may be caused by mycoplasma dispar.

• Pneumonia, Necrotizing

  severe complication of pneumonia characterized by liquefaction of lung tissue.

• Pneumonia, Pneumococcal

  a febrile disease caused by streptococcus pneumoniae.

• Pneumonia, Pneumocystis

  a pulmonary disease in humans occurring in immunodeficient or malnourished patients or infants, characterized by dyspnea, tachypnea, and hypoxemia. pneumocystis pneumonia is a frequently seen opportunistic infection in aids. it is caused by the fungus pneumocystis jirovecii. the disease is also found in other mammals where it is caused by related species of pneumocystis.

• Pneumonia, Progressive Interstitial, of Sheep

  chronic respiratory disease caused by the visna-maedi virus. it was formerly believed to be identical with jaagsiekte (pulmonary adenomatosis, ovine) but is now recognized as a separate entity.

• Pneumonia, Rickettsial

  pneumonia caused by infection with bacteria of the family rickettsiaceae.

• Pneumonia, Staphylococcal

  pneumonia caused by infections with bacteria of the genus staphylococcus, usually with staphylococcus aureus.

• Pneumonia, Ventilator-Associated

  serious inflammation of the lung in patients who required the use of pulmonary ventilator. it is usually caused by bacterial cross infection in hospitals.

• Pneumonia, Viral

  inflammation of the lung parenchyma that is caused by a viral infection.

• Pulmonary Eosinophilia

  a condition characterized by infiltration of the lung with eosinophils due to inflammation or other disease processes. major eosinophilic lung diseases are the eosinophilic pneumonias caused by infections, allergens, or toxic agents.

• Radiation Pneumonitis

  inflammation of the lung due to harmful effects of ionizing or non-ionizing radiation.

• Pneumovirus

  a genus of the family paramyxoviridae (subfamily pneumovirinae) where the human and bovine virions have neither hemagglutinin nor neuraminidase activity. respiratory syncytial virus, human is the type species.

• Pulmonary Alveoli

  small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place.

• Streptococcus pneumoniae

  a gram-positive organism found in the upper respiratory tract, inflammatory exudates, and various body fluids of normal and/or diseased humans and, rarely, domestic animals.

• Rickettsiaceae

  a family of gram-negative bacteria belonging to the order rickettsiales.

• Eosinophils

  granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin.

• Grade 2 Pneumonitis, CTCAE|Grade 2 Pneumonitis

  symptomatic; medical intervention indicated; limiting instrumental adl or mild/moderate impact on age-appropriate normal daily activity (pediatric)

• Grade 3 Pneumonitis, CTCAE|Grade 3 Pneumonitis

  severe symptoms; oxygen indicated; limiting self-care adl or severe impact on age-appropriate normal daily activity (pediatric)

• Erosive Gastritis

  gastritis that is characterized by erosion of the mucosal surface.

• Acute Interstitial Pneumonia|AIP|Acute Interstitial Pneumonitis

  a rare, rapidly progressing interstitial lung disorder characterized by diffuse and bilateral alveolar damage. patients present with sudden onset of dyspnea and rapid development of respiratory failure. management is supportive and hospitalization and mechanical ventilation are usually required.

• Aspiration Pneumonitis|Aspiration Pneumonia|Aspiration Pneumonia

  inflammation of the lungs due to the inhalation of solid or liquid material.

• Bird Fancier's Lung|Avian Hypersensitivity Pneumonitis|Bird fancier's lung|Bird-Breeder's Lung|Pigeon-Breeder's Lung

  hypersensitivity granulomatous pneumonitis caused by the inhalation of avian antigens that are present in the dust of the droppings and feathers of many species of birds. in the acute phase it manifests as fever, chills, dyspnea, cough, and chest tightness. chronic exposure may lead to interstitial lung fibrosis.

• Chemical Pneumonitis

  inflammation of the lungs caused by the inhalation or aspiration of chemicals.

• Extrinsic Allergic Alveolitis|Allergic Pneumonitis|Hypersensitivity Pneumonitis

  an inflammatory interstitial lung disease caused by hypersensitivity reaction to inhalation or ingestion of antigens. the antigens are usually related to the patient's occupation. it can present as an acute illness with flu-like symptoms, subacute with repeated episodes of pneumonia, or chronic with dyspnea and productive cough. the majority of patients recover following the cessation of the exposure to the antigen that causes the disease. chronic exposure may eventually progress to interstitial lung fibrosis.

• Fibrotic Hypersensitivity Pneumonitis|fHP

  interstitial lung fibrosis resulting from chronic hypersensitivity pneumonitis.

• Grade 1 Pneumonitis, CTCAE|Grade 1 Pneumonitis

  asymptomatic; clinical or diagnostic observations only; intervention not indicated

• Grade 2 Pneumonitis, CTCAE|Grade 2 Pneumonitis

  symptomatic; medical intervention indicated; limiting instrumental adl

• Grade 3 Pneumonitis, CTCAE|Grade 3 Pneumonitis

  severe symptoms; limiting self care adl; oxygen indicated

• Grade 4 Pneumonitis, CTCAE|Grade 4 Pneumonitis

  life-threatening respiratory compromise; urgent intervention indicated (e.g., tracheotomy or intubation)

• Grade 5 Pneumonitis, CTCAE|Grade 5 Pneumonitis

  death

• Hypersensitivity Pneumonitis due to Other Organic Dusts|Hypersensitivity pneumonitis due to Other organic dusts

  evidence of hypersensitivity pneumonitis due to other organic dusts.

• Hypersensitivity Pneumonitis due to Unspecified Organic Dust|Hypersensitivity pneumonitis due to unspecified organic dust

  evidence of hypersensitivity pneumonitis due to unspecified organic dust.

• Idiopathic Interstitial Pneumonia|IIP|Idiopathic Interstitial Pneumonitis

  non-infectious inflammation of the interstitial lung tissue of unknown etiology. this category includes desquamative interstitial pneumonia, usual interstitial pneumonia, lymphocytic interstitial pneumonia, acute interstitial pneumonia, and nonspecific interstitial pneumonia.

• Interstitial Pneumonia|Interstitial Pneumonitis

  inflammation of interstitial lung tissue, usually associated with infection.

• Lymphocytic Interstitial Pneumonia|Diffuse Hyperplasia of Bronchus-Associated Lymphoid Tissue|LIP|Lymphocytic Interstitial Pneumonitis|Lymphocytic interst. pneumonitis|Lymphocytic interstitial pneumonitis

  interstitial pneumonia characterized by the presence of bibasilar pulmonary interstitial infiltrates composed of lymphocytes and plasma cells. it may be associated with autoimmune and lymphoproliferative disorders. signs and symptoms include fever, cough, and dyspnea. symptomatic patients may require immunosuppressive treatment.

• Pneumonitis

  an inflammatory process affecting the lung parenchyma. it is a milder form of lung inflammation compared to pneumonia.

• Pneumonitis, CTCAE|Pneumonitis|Pneumonitis

  a disorder characterized by inflammation focally or diffusely affecting the lung parenchyma.

• Radiation-Induced Pneumonitis

  pneumonitis that is associated with irradiation.

• Steroid-Refractory Pneumonitis

  pneumonitis that does not respond to corticosteroid therapy.

• Ornithosis

  disease caused by the chlamydophila psittaci bacteria, usually transmitted from birds to humans.

Pneumonia

Pneumonia is an infection in one or both of your lungs. It causes the air sacs of your lungs to fill up with fluid or pus. Pneumonia can range from mild to severe, depending on what caused it, your age, and your overall health.

The full article covers:

• What is pneumonia?
• What causes pneumonia?
• Who is more likely to develop pneumonia?
• What are the symptoms of pneumonia?
• What other problems can pneumonia cause?
• How is pneumonia diagnosed?
• What are the treatments for pneumonia?
• Can pneumonia be prevented?

Read the full article at MedlinePlus

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