What Is Nontuberculous Mycobacterial Lung Disease?

Medically Reviewed by Paul Boyce, MD on November 04, 2023
3 min read

Nontuberculous mycobacteria are tiny germs found in soil, water, and on both tame and wild animals. They’re harmless to most people. But sometimes when these bacteria get into your body, they can cause a serious lung disease.

NTM infections are becoming more common, especially among people ages 65 and older. These infections are increasing at about 8% each year. Roughly 75,000 - 105,000 people will be diagnosed each year in the U.S.

This infection can slowly scar and damage your lungs. If you get a mild case, you might not need treatment. If you do, it could take as long as 2 years of treatment to clear it up. You might even need ongoing treatment.

NTM lung disease isn’t tuberculosis (TB). You can’t get it from someone else or pass it to others.

NTM lung disease is caused by breathing in air or mist that has the bacteria in it. The bacteria get into your lung tissue and cause an infection. Your airways become inflamed.

More than 120 types of NTM bacteria can cause this infection. Most people who breathe or swallow these germs don’t get sick. We don’t know why some people aren't affected by the bacteria while others get sick.

You’re more likely to get the disease if the bacteria get into your lungs and you already have one of these health problems:

You also may be at higher risk for NTM lung disease if you’re:

  • A smoker or former smoker
  • Older
  • A slender, white female who is tall, has a curved spine, an abnormally shaped breastbone, and mitral valve prolapse

NTM germs lurk in warm, wet places like hot tubs, heated indoor pools, and steamy bathrooms. If you’re at risk for the disease, it’s wise to avoid hot tubs or indoor pools. Use a vent fan to clear up steam after a shower or bath.

They’re different for each person. Some people may have mild symptoms, while others have severe problems:

Other symptoms include wheezing, chest pain, and repeat lung infections. Over time, your lungs don’t work as well as they once did.

NTM lung disease comes in two main types. The less severe kind is called nodular bronchiectasis. It causes scarring in your airways. That makes it hard for you to cough up and clear out mucus. Older women are most at risk for this type.

A more severe form is called cavitary NTM lung disease. In addition to scars, cavities or pits also form in your lungs. This could lead to lung failure. But NTM lung disease isn’t usually fatal.

It’s less common, but NTM infections can also show up in your skin, bones, lymph nodes, or all over your body.

A lung doctor (they are called pulmonologists) can figure out if you have NTM lung disease and help you get treatment.