Non-tuberculous mycobacteria (NTM)
Non-tuberculous mycobacteria (NTM) are a group of bacteria commonly found in natural and household environments, including tap water, showers, soil and dust. Most healthy people breathe in these germs without becoming ill, as their lungs can clear them naturally.
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NTM lung disease develops when these bacteria settle in the lungs, grow slowly and cause ongoing infection and irritation in the lungs. This is more likely to affect people with underlying lung conditions or those with weakened immune systems.
There are many types of NTM. The most common causes of lung disease include Mycobacterium avium complex (MAC) and Mycobacterium abscessus. Sometimes doctors will use the specific bacteria name (like Mycobacterium avium) when they discuss the condition with patients, before using the term NTM.
In Europe, NTM lung disease affects approximately 5–7 in every 100,000 people, although rates vary between countries. Around the world, rates can be higher. For example, in Japan, around 25 people in every 100,000 are affected. The disease is being diagnosed more often. This is likely due to increased awareness, improved testing methods and an ageing population, as older people are more vulnerable to infection.
How NTM affects the lungs
NTM bacteria mainly infect the airways. This causes swelling and irritation (inflammation) in the lungs and mucus (sputum) build-up, which can damage lung tissue over time and gradually reduce lung function. As the lungs become more damaged, breathing can become more difficult and the risk of additional infections increases.
Types of NTM lung disease
NTM lung disease usually affects people in two common ways:
Nodular bronchiectatic
This is the milder form. The infection affects the small airways, which can become widened, scarred and less able to clear mucus. This can lead to repeated infections and a long-term cough.
This type often affects older women who have never smoked and do not have other long-term lung diseases.
Fibrocavitary
This is a more serious and usually gets worse over time. The infection causes scarring and the development of holes, known as cavities, in the lung tissue. It is more common in people with a history of smoking or pre-existing lung conditions such as chronic obstructive pulmonary disease (COPD) or lungs damaged by previous tuberculosis (TB). It can lead to more severe breathing difficulties and lung damage.
Learn from people living with NTM
Justine: My experience with Nontuberculous Mycobacteria and bronchiectasis
Symptoms
The main symptoms of NTM lung disease include:
- A long-lasting cough
- Coughing up mucus and sometimes blood
- Extreme tiredness (fatigue)
- Shortness of breath
- Night sweats or fever
These early signs are more likely to be significant in people who already have lung problems.
Differences between types of NTM lung disease
Symptoms and how the illness develops can vary depending on the type of NTM lung disease:
Nodular bronchiectatic
- Usually causes a long-term cough with mucus
- Symptoms are generally milder and mostly related to damage in the airways
Fibrocavitary
- Causes more severe lung damage
- Symptoms may include coughing up blood and a more rapid worsening of health
How the disease progresses
NTM lung disease usually develops slowly over many months and is considered a long-term lung infection. Early symptoms may be mild, such as a long-lasting cough or extreme tiredness (fatigue).
In some people, the condition remains stable for long periods. In others, it gradually gets worse, leading to repeated lung infections and reduced lung function. Doctors monitor the condition using scans and lung function tests to decide when treatment is needed to prevent further damage.
Causes and risk factors
Who is most at risk?
NTM lung disease is more likely to develop in people whose lungs are already damaged by previous infections or long-term lung conditions.
Other factors that increase risk include:
- Older age
- Problems with the immune system
- Use of steroid inhalers
Many people with asthma or other lung conditions are prescribed steroid inhalers to control their symptoms. These medicines are important for managing underlying conditions and should not be stopped without medical advice. If you have concerns about steroid treatment and NTM risk, discuss them with your healthcare team.
Factors linked to more severe disease
Some people may experience worse outcomes due to additional health problems or characteristics. These include:
- Existing lung conditions such as COPD, interstitial lung disease (ILD), bronchiectasis, cystic fibrosis or asthma
- Other health conditions like diabetes or heart failure
- Older age and male sex
- Low body weight or low red blood cell levels (anaemia)
- Signs of swelling and irritation in the body (e.g., raised C-reactive protein in blood tests)
Is NTM lung disease contagious?
NTM lung disease does not spread from person to person. Most people get infected from the environment, such as soil, water or dust.
However, some research suggests that M. abscessus, a type of NTM bacteria, may spread through shared surfaces, equipment or the clinic environment within the cystic fibrosis (CF) community, rather than through direct contact between people. Because of this, clinics that care for people with CF often take extra precautions when someone has M. abscessus, to help prevent it spreading.
Prevention
NTM lung disease cannot be completely prevented because these bacteria are common in the environment. However, the risk of developing the condition can be lowered. These steps can be helpful, particularly for people with existing lung conditions:
Water and household exposure:
- Keep home water heaters at 55–60°C (130–140°F) to reduce bacterial growth.
- Limit exposure to hot and humid environments that generate water droplets (e.g. hot tubs, saunas, hammams and indoor swimming pools).
- Clean and replace showerheads regularly.
- Use good ventilation when showering or bathing.
- Ensure ventilation systems are regularly cleaned and maintained.
- Open windows regularly to help air circulate
- Pay attention to indoor air quality and avoid smoke, strong scents or other irritants in the air.
Soil and dust exposure:
- Wear a mask when gardening or working with soil.
- Avoid stirring up dust in enclosed spaces.
Supporting overall lung health:
- Avoid smoking and second-hand smoke.
- Follow recommended airway clearance routines if you have bronchiectasis or another lung condition.
- Stay up to date with vaccinations (such as flu and pneumonia) to help prevent other infections.
- If you have acid reflux (stomach acid coming up into your throat), talk to your doctor, as it may increase the risk of NTM infection.
These measures do not remove the risk entirely, but they can help people at higher risk protect their lungs and stay healthier.
Visit our ‘keeping lungs healthy‘ hub for more information to support your lung health.
Diagnosis
Doctors diagnose NTM lung disease using a combination of symptoms, scans and laboratory tests.
Symptoms:
Doctors will look for the symptoms listed above and take notes on how long these have been happening.
Scans of the lungs:
Scans help doctors see what is happening in the lungs. These could include:
- Chest X-rays
- Detailed lung scans, such as CT scans, to detect cavities or widened airways.
Laboratory tests:
Samples taken from your lungs over can be tested in a laboratory to see if NTM bacteria are found. Multiple positive samples are needed to confirm infection because NTM bacteria are common in the environment.
Other tests if needed could include:
- Bronchoscopy: a procedure to collect fluid from the lungs
- Lung biopsy: removing a small sample of lung tissue for testing
Diagnosing NTM lung disease can be challenging because:
- Symptoms are similar to other lung conditions
- NTM bacteria are common, so finding them does not always mean you have the condition
- Multiple tests and careful evaluation are required to confirm a true infection.
Treatment and management
Because diagnosis can take months, your doctor may check your condition carefully before deciding whether antibiotic treatment is needed. This ensures that treatment is only given if it is really needed and if you will benefit from it.
Antibiotic treatment
When treatment is needed, it usually involves a combination of antibiotics taken for a long period. This can often be 12 months or more after tests show the infection is cleared. The exact combination depends on the type of NTM bacteria, but commonly three or more antibiotics are taken together.
- Most medications are tablets that you swallow, although some people may need to take antibiotics through a drip in the vein. This is known as an intravenous antibiotic.
- In certain cases, people may also need to take inhaled antibiotics, that are delivered through inhalers or nebulisers.
- Surgery is rare but may be considered in specific situations.
Side-effects and challenges of treatment
Because treatment usually involves several medications, side effects can occur, although not everyone experiences them.
Common side effects include:
- Stomach upset, nausea, diarrhoea, or loss of appetite
- Extreme tiredness
- Changes in hearing or vision
- Liver problems
- Dry skin or changes in skin colour
- Heart rhythm disturbances
Some side effects require urgent medical attention. Your healthcare team will guide you on what to watch for and who to contact if you have any problems. Blood-tests and other checks will take place regularly. Your team will adjust medicines as needed to manage side effects and ensure the best chance of success. Even people not taking antibiotics may need long-term monitoring to track the disease and any complications.
People with NTM lung disease may also develop other lung infections (co-infections), such as Pseudomonas bacteria, Haemophilus bacteria or Aspergillus (a type of fungus), which require additional monitoring and management.
Supportive therapies and lifestyle factors
In addition to medication, the following can help manage symptoms and support lung health:
- Airway clearance techniques to remove mucus (e.g., chest physiotherapy, oscillating devices, breathing exercises)
- Regular exercise to improve lung strength and energy
- Staying well-hydrated
- Eating well, especially if weight loss is an issue
- Avoiding smoking and second-hand smoke
- Psychological support to manage anxiety, low mood or emotional impact
These measures may improve well-being and help treatment be more effective, although research on their impact is limited.
Many people benefit from multidisciplinary care involving pulmonologists, infectious disease specialists, physiotherapists, nurses and, when needed, mental health professionals.
Taking an active role in your care can be helpful. Some patients have found it useful to keep a “lung diary” to track symptoms, infections and treatment effects. Others may find it helpful to ask about airway clearance techniques or attend physiotherapy sessions if recommended. These tools can help you feel more in control, but they are optional.
Managing underlying lung conditions
Managing any lung conditions you already have is very important. Damaged airways can make it easier for NTM to grow. Taking good care of your lungs and following treatment plans, including regular airway clearance, prescribed inhalers and ongoing follow-up, can:
- Reduce symptoms
- Lower the risk of new infections
- Improve treatment success
- Support overall lung health
Even after NTM infection has been cleared, some people continue to be at risk due to underlying conditions such as bronchiectasis or asthma. Long-term checkups with a specialist may still be needed.
Living with NTM lung disease
Living with NTM lung disease can affect daily life in different ways. Extreme tiredness, cough and shortness of breath may make social activities more challenging.
Some people find that their lungs feel more at risk after diagnosis or treatment. Chest infections may be harder to clear and greater caution in crowded or high-risk environments may feel needed.
The complexity of managing the condition, including taking multiple medications for over a year, coping with side effects and attending regular medical appointments, can add to the burden.
Some people may also experience feelings of isolation, anxiety or low mood after diagnosis.
Despite these challenges, many patients are still able to work, travel and stay active, often by pacing themselves and taking steps to protect their lung health.
Support from caregivers, family, friends and healthcare providers can make daily life easier to manage.
Because NTM is relatively uncommon, some healthcare professionals may be less familiar with it. Keeping a summary of your diagnosis and treatment history, and knowing reliable information sources or specialist centres, can be helpful — especially when travelling or when new medications are prescribed.
Research and future developments
Your healthcare provider can help you find reliable resources and guide you to services in your area. Accessing support early can make managing NTM lung disease easier and help improve quality of life.
Known patient organisations who can provide regional support and information:
Further resources
Your healthcare provider can help you find reliable resources and guide you to services in your area. Accessing support early can make managing NTM lung disease easier and help improve quality of life.
Known patient organisations who can provide regional support and information:
Further reading:
Last updated 2026
This content was developed with input from EMBARC, a pan-European network, Professor Natalie Lorent, Professor Hayoung Choi. Patient perspectives were provided with the support of NTM organisations:
