Signs Your Air Conditioner Makes You Sick

Ever wonder if you can get a cough from an air conditioner? We’ll take you through how the cold and pressure may lead to cough or potentially even a cold.

Have you ever wondered if you can get a cough or cold from the air conditioning? You’re not alone, and the answer is yes. If you feel like you have the flu and you cough and experience shortness of breath a few hours after you turn your AC on, your unit may be the culprit. The problem is a condition called hypersensitivity pneumonitis, and it goes by multiple nicknames, including air conditioner lung.

What causes this condition and should you be concerned?

What is hypersensitivity pneumonitis?

Hypersensitivity pneumonitis is an inflammation of the lungs caused by an allergy to dust or other particles, like fungus and molds, present in the air. When you breathe in the particles, or allergens, the air sacs in your lungs fill with white blood cells or, occasionally, fluid. Repeated exposure to the allergens means continued inflammation, which can lead to the formation of scar tissue.


There are more than 300 allergens that can cause hypersensitivity pneumonitis. In the case of air conditioner lung, the condition is caused by fungus that develops in AC units that have not been properly maintained. Other common causes include:

  • Mold from hay, straw and grain
  • Bird feathers and droppings
  • Bacteria in water vapor from indoor hot tubs

Many people who develop hypersensitivity pneumonitis are exposed to allergens as a result of their work. High-risk professions include farming, bird and poultry handling, veterinary medicine, lumber milling, and grain and flour processing, as well as certain types of manufacturing, such as plastics and electronics.


Symptoms of air conditioner lung typically appear 4-6 hours after exposure to the allergen and may include:

  • Dry cough
  • Shortness of breath
  • Tightness in the chest
  • Fever
  • Chills
  • Tiredness

Symptoms may last anywhere from 12 hours to a few days. Repeated exposure may also result in weight loss.

Is it serious?

Generally speaking, the inflammation associated with hypersensitivity pneumonitis can be reversed if it’s caught early. The American Lung Association recommends visiting your doctor if you develop any of the symptoms associated with the condition and cautions that, while hypersensitivity pneumonitis may feel like the flu, unlike the flu, it can occur any time of the year.

If left untreated and scar tissue is allowed to develop, air conditioner lung can become more serious. Lung scarring is permanent and may result in trouble breathing normally.


Hypersensitivity pneumonitis is typically diagnosed through a physical exam and a series of tests that may include a chest X-ray, lung function tests, blood tests to look for allergen antibodies and a bronchoscopy.

Treatment may include steroids for up to three months, although the best method of treatment is avoiding exposure to the allergens. Sometimes, this may require changing homes or jobs.

Unfortunately, there is no treatment for cases that involve scar tissue.


There are a few steps you can take to help prevent hypersensitivity pneumonitis. These include:

  • Removing standing water inside and outside your home – this breeds bacteria
  • Ensure humidity is below 60 percent
  • Quickly repair water damage to carpet, furnishings and drywall
  • If hay or grain are present near your home or work, make sure they are dry and properly stored

For hypersensitivity pneumonitis caused by air conditioning specifically, the most important step you can take to avoid the condition is making sure your unit is properly maintained and that the air inside your home or office is as clean as possible. Change your filter regularly and schedule routine maintenance checks with an HVAC professional. Pay special attention to any odd smells, such as dirty socks or mildew, which may indicate the presence of allergens within your unit.

Of course, a home warranty with air conditioner coverage from American Home Shield® provides coverage for unexpected breakdowns and repairs, which can help protect your home. 

Source: AHS