What Is Nontuberculous Mycobacterial Lung Disease?

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.

But it’s rare. In a whole year only about 2 out of every 100,000 people in the U.S. get it.  

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.

What Causes It?

You can get it if you drink water, eat food, or breathe 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:

  • Any disease that has caused lung damage, like chronic obstructive pulmonary disease (COPD), emphysema, or bronchiectasis
  • Silicosis, or “black lung disease”
  • Weakened immune system from HIV infection or AIDS
  • Had or about to have a lung transplant
  • Cystic fibrosis
  • Past infection with tuberculosis
  • Alcoholism
  • Acid reflux
  • Any autoimmune disease like rheumatoid arthritis or Sjogren’s syndrome

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

  • A smoker or former smoker
  • Older
  • Female
  • Slender
  • White

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.


What Are the Symptoms?

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

  • Cough, sometimes with blood
  • Fatigue
  • Fever
  • Large amount of mucus
  • Loss of appetite or weight
  • Night sweats
  • Shortness of breath

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.

WebMD Medical Reference Reviewed by Neha Pathak, MD on June 02, 2017



University of California San Francisco Medical Center: “Nontuberculous Mycobacteria.”

American Lung Association: “Learn About Nontuberculous Mycobacteria (NTM),” “NTM Symptoms, Causes & Risk Factors.”

National Organization of Rare Diseases: “Nontuberculous Mycobacterial Lung Disease.”

Journal of Thoracic Disease: “Nontuberculous mycobacterial pulmonary infections.”

UpToDate: “Epidemiology of nontuberculous mycobacterial infections.”Epidemiology of nontuberculous mycobacterial infectionsEpidemiology of nontuberculous mycobacterial infectionsEpidemiology of nontuberculous mycobacterial infections

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