Skip to Main Content
Signs & Symptoms Pulmonology

Hypersensitivity Pneumonitis
Signs and Symptoms

Hypersensitivity pneumonitis is subdivided into two forms: acute and chronic. Symptoms differ for each form.

Acute HP Symptoms

The acute form of HP occurs after heavy, often short-term exposure to the antigen. Symptoms appear relatively suddenly and include:

  • Fever
  • Chills
  • Fatigue
  • Breathlessness
  • Chest tightness
  • Cough

If the person is removed from the antigen exposure, the symptoms usually resolve over 24 to 48 hours. Recovery is often complete.

Chronic HP Symptoms

The chronic form of HP is thought to occur due to longer term, low-level exposure to the antigen, and it often causes more subtle symptoms. Patients with chronic HP often describe chronic symptoms, such as shortness of breath or cough, that have gotten worse. Symptoms may worsen at work, at home or wherever the patient is being exposed to the antigen, but most often, patients with chronic HP haven't had acute episodes. Most patients seen in our clinic have the chronic form of HP.

UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.