Hypersensitivity Pneumonitis (HP) is a disease that occurs when the lungs become inflamed from breathing in foreign substances like molds, dusts, and chemicals. Most people who breathe in these substances don’t develop HP. However, those that do may develop one of two types: acute (short-term) and chronic (ongoing). Acute HP leads to chills, body aches, coughing, and chest tightness within 2-9 hours of exposure. After hours or days of no contact with the inflammatory substance, symptoms usually go away. If symptoms don't go away, it may lead to chronic HP. Symptoms of chronic HP occur over the course of months, leading to a worsening cough, shortness of breath with physical activity, fatigue, and weight loss. Severe HP may cause a widening and rounding of the tips of the fingers. Symptoms may continue or worsen even after avoiding the original substance and can lead to long-term lung damage. In cases of chronic or severe HP, doctors may prescribe anti-inflammatory drugs to decrease swelling in the lungs and prevent further damage.