NTM Lung Disease: A Diagnosis Challenge

Medically Reviewed by Paul Boyce, MD on November 17, 2021

Nontuberculous mycobacterial (NTM) lung disease is an infection caused by a type of bacteria. It can have the same symptoms as other lung diseases, so you need to see your doctor for a diagnosis.

If you have an NTM lung infection, you may notice:

You probably won’t have the exact symptoms as someone else with this disease. And the ones you do get may seem mild at first. NTM bacteria can live inside your lungs for a long time before you think something’s wrong.

Go to the doctor if you have a cough that sticks around for a long time. If you also have night sweats, fevers, shortness of breath, and weight loss that’s hard to explain, get checked out right away.

Your doctor may diagnose you or send you see a pulmonologist (a doctor who specializes in lung problems).

To diagnose NTM lung disease, your doctor will:

  • Do a physical exam
  • Go over your medical history
  • Take a chest X-ray or do a test called a CT scan to take a picture of the inside of your lungs
  • Get a sample of your spit or coughed-up mucus and saliva

A chest X-ray may show signs of NTM lung disease. A CT scan will show more details that point to this infection.

If NTM is to blame, the doctor will see small nodules inside your lungs when they look at the CT scan. They often make a pattern that looks like a budding tree. The CT scan can also show:

  • Small holes in your lungs (the doctor may call them cavities) that signal more advanced disease
  • Thickened, inflamed airways
  • Sores (the doctor might call them lesions)
  • Areas of your lungs filled with pus, blood, or tissue (the doctor might call them infiltrates)

The doctor will use a sample of the gunk you’re coughing up to look for the NTM bacteria that cause this infection. This test is called a culture. To be sure you have a good sample, you may need to cough up mucus on a few different days.

Your doctor sends your sample to a lab, where doctors test it to see what kind of bacteria are in it. Your treatments will be based on the exact type of NTM bacteria you have.

If you can’t cough up enough mucus to test, you may need a procedure called a bronchoscopy. Your doctor runs a thin tube through your nose or mouth, and it goes into your lung to collect some fluid and mucus.

No. It has the same symptoms as other infections, like tuberculosis. So your doctor might think you have another disease or want to rule that out first.

If you have mild symptoms, it can take a long time for your doctor to suspect NTM as the cause.

Your lab test is a sure way to tell if you have NTM disease, because it’ll find these bacteria.

NTM infections can also look like:

Talk to your doctor if you have symptoms that could be NTM lung disease or another lung problem. Once you get a diagnosis, you can start treatment right away.

Show Sources


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

American Lung Association: “Diagnosing and Treating NTM Pulmonary Disease,” “NTM Symptoms, Causes and Risk Factors.”

Tuberculosis and Respiratory Diseases: “Diagnosis and Treatment of Nontuberculous Mycobacterial Lung Disease: Clinicians’ Perspectives.”

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

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