Medically reviewed in November 2022
MAC lung disease is a bacterial infection of the lungs. It’s caused by bacteria that are commonly found in soil and water, which can be inhaled into the lungs as a person breathes or when they drink water.
Most people who come into contact with these bacteria will not experience any illness. Others can develop a serious, life-threatening lung infection. Symptoms of MAC lung disease can include chronic cough (which may include coughing up mucus or blood), fatigue, unintended weight loss, difficulty breathing, night sweats, and low-grade fever. MAC lung disease also has a high mortality rate—roughly one in four people who have MAC lung disease die within five years.
Fortunately, MAC lung infections can be cured with the right treatment. Here are a few important facts to know about treating MAC lung disease.
The providers that treat MAC lung disease
MAC lung disease may be treated by healthcare providers that specialize in pulmonary medicine and/or infectious disease specialists. Because MAC lung disease often affects people who already have an existing health condition—such as an autoimmune disorder, inflammatory condition, or ongoing respiratory illness—diagnosis and treatment may begin with a healthcare provider a person is already working with.
Treatment starts with diagnosis
The first step to treating any infection is getting an accurate diagnosis. Diagnosing MAC lung disease commonly involves a clinical exam as well as imaging tests to look for signs of infection in the lungs.
A sputum culture is an essential part of diagnosis for MAC lung disease, because it helps rule out other potential causes of infection, including tuberculosis (TB). Sputum is the mucus and other substances that are coughed up from the lungs during a productive cough. Analyzing sputum can provide valuable clues to what is causing an infection.
For the patient, this test involves coughing up a sample of sputum. If a sputum culture cannot provide an answer, a procedure called a bronchoscopy can also be used to collect a sample from the lungs.
Treatment for MAC lung disease
Treatment for MAC lung disease will depend on the severity of a person’s symptoms, their overall health, their medical history, and other factors.
In cases where symptoms are mild and imaging tests show minimal signs of infection, treatment may only involve follow-up exams to check a person’s breathing and take additional sputum cultures, giving the infection a chance to clear up.
Airway clearance is another approach to treatment. This involves therapies that help a person breathe better, help the lungs clear out sputum, and give the body a chance to clear the infection. These may also be prescribed during treatment with antibiotics or during recovery.
More severe infections will require treatment with antibiotics. Because MAC lung disease is often resistant to treatment, several different antibiotics will be taken together, and taken for an extended period of time (12 to 18 months). Treatment may also include oxygen therapy to help maintain healthy blood oxygen levels.
It can be difficult to take these medications for so many months, but good adherence will give a person the best chance of being cured. MAC lung disease can be difficult to cure, and it also has a high rate of recurrence. An infection will be considered cured when follow-up sputum cultures show no signs of infection for at least one year. If antibiotics are unable to cure an infection, surgery may be needed to remove part of the infected lung.
Healthy habits and treatment adherence
Avoiding irritants (like cigarette smoke), preventing infections with immunizations and good hygiene (like hand washing), and a healthy lifestyle (staying physically active and eating a well-balanced diet) are also important to managing MAC lung disease, both during and after treatment. Healthcare providers will be able to recommend additional steps for protecting the lungs against MAC lung disease and other infections.
