Finding out what caused your hypersensitivity pneumonitis can be hard. The best way is to thoroughly go over your life and health history with your doctor. But some people never find out what caused it.

Your doctor will go over a questionnaire with you about your health and life. This can include your work history, hobbies, home life, and any medications you’ve taken. This can help narrow down what could have caused your hypersensitivity pneumonitis.

The doctor might ask you to avoid certain things to see if it makes your breathing better. This can help figure out what’s causing the problem. For example, they might ask you to try sleeping with different bedding or leaving your pets in a different room at night.

Some kinds of blood tests may help narrow down what could be the cause, but blood tests can’t find the cause on their own.

Some of the things that most commonly cause hypersensitivity pneumonitis are birds droppings, bird feathers, mold, dust from farms, and bacteria found in hot tub water. Not everyone who breathes these things in will get it.

A lot of people never figure out what caused their hypersensitivity pneumonitis. Studies have found anywhere from 1 in 4 (25%) to 1 in 2 (50%) people never find out what caused it.


Talking to your doctor and avoiding likely causes are a part of figuring out where your hypersensitivity pneumonitis got its start.