Signs and symptoms vary between acute, subacute, and chronic types of hypersensitivity pneumonitis. If your condition is not diagnosed or well controlled by treatment, it can lead to irreversible lung damage and other potentially fatal complications.

Signs and Symptoms

The following are common signs and symptoms of acute, subacute, and chronic hypersensitivity pneumonitis. 

Signs and symptoms of acute, subacute, and chronic hypersensitivity pneumonitis may include flu-like illness including fever, chills, muscle or joint pain, or headaches; rales; cough; chronic bronchitis; shortness of breath; anorexia or weight loss; fatigue; fibrosis of the lungs; and clubbing of fingers or toes.

While some signs and symptoms occur in several types of hypersensitivity pneumonitis, they may vary in severity. The exact signs and symptoms you experience also may vary.

Learn about how exposure history affects whether you show signs and symptoms of acute, subacute, or chronic hypersensitivity pneumonitis.

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Acute hypersensitivity pneumonitis is the most common form of this condition. It is thought to occur as a result of a short period of exposure to a large amount of causative substance. Symptoms usually occur within 9 hours of being exposed again to a substance that triggers your immune system. If an additional exposure does not occur, symptoms usually resolve after a few days. Subacute and chronic forms of hypersensitivity pneumonitis occur after multiple or continuous exposures to small amounts of a causative substance. Approximately 5 percent of patients develop chronic disease.

Hypersensitivity Pneumonitis – Signs, Symptoms, and Complications

Hypersensitivity pneumonitis may cause the following potentially fatal complications if the condition is not diagnosed or well controlled by treatment.

  • Irreversible lung damage and permanently reduced lung function because of severe fibrosis and impaired ability to oxygenate the blood during normal breathing.
  • Pulmonary hypertension due to damage of blood vessels in the lungs.
  • Heart failure because inflammation makes it harder for the heart to pump blood to and through the lungs.

Look for – Hypersensitivity Pneumonitis – Signs, Symptoms, and Complications

  • Diagnosis will explain tests and procedures that are used to detect signs of hypersensitivity pneumonitis and help rule out other conditions.
  • Treatment will discuss possible treatment-related complications.