Mycoplasma pneumonia (MP) is a type of bacteria that can cause many symptoms, including dry cough, fever, and mild shortness of breath on exertion.

The Mycoplasma pneumonia bacterium is one of the most recognized of all human pathogens, and there are more than 200 different known species.

Most people with respiratory infections caused by Mycoplasma pneumoniae don’t develop pneumonia. For this reason, MP is known as an atypical pneumonia and is sometimes called walking pneumonia.

Mycoplasma pneumonia spreads quickly through contact with respiratory fluids in crowded areas, like schools, college campuses, and nursing homes. When someone coughs or sneezes, moisture containing the MP bacteria is released into the air, and others around them can easily breathe the bacteria in.

Once inside the body, the bacterium can attach itself to your lung tissue and multiply until a full infection develops.

About 7 to 20 percent of cases of community-acquired (outside of a hospital) pneumonia happen as a result of infection by atypical bacterial microorganisms.

Of these, Mycoplasma pneumoniae causes the most infections, though only about 10% of people infected will actually develop pneumonia.

The bacteria can also cause tracheobronchitis (chest colds), sore throats, and ear infections, in addition to pneumonia.

Learn more about pneumonia.

The immune system can fight off MP in many healthy adults before it grows into an infection. Those most at risk include:

  • older adults
  • people who have diseases that compromise their immune system, like HIV, or who are on chronic steroids, immunotherapy, or chemotherapy
  • people who have lung disease
  • people who have sickle cell disease
  • children younger than age 5

MP symptoms are different from those of typical pneumonia caused by common bacteria, like Streptococcus and Haemophilus.

Patients usually do not have severe shortness of breath, high fever, and a productive cough with MP. Instead, they have a low-grade fever, dry cough, mild shortness of breath (especially with exertion), and fatigue.

MP may mimic an upper respiratory infection or common cold rather than a lower respiratory infection or pneumonia. A dry cough is the most common sign of infection. Other symptoms may be:

In rare cases, the infection can become dangerous and damage the heart or central nervous system. Examples of these disorders include:

In rare cases, MP may be fatal.

In some cases, an MP infection can become dangerous. If you have asthma, MP can make your symptoms worse. MP can also develop into a more severe case of pneumonia.

Long-term MP is rare, but some research suggests that it could play a role in chronic lung disease. In rare cases, untreated MP can be fatal.

Other potential complications of MP include:

See your doctor right away if you experience any symptoms, especially if they last for more than 2 weeks.


Antibiotics are the first line of treatment for MP. Children get different antibiotics than adults to prevent potentially dangerous side effects.

Macrolides, the first choice of antibiotics for children, include:

Antibiotics prescribed for adults include:


Sometimes antibiotics alone are not enough, and you have to be treated with corticosteroids to manage the inflammation. Examples of such corticosteroids include:

  • prednisolone
  • methylprednisolone

Immunomodulatory therapy

If you have severe MP, you may need other “immunomodulatory therapy” in addition to corticosteroids, including intravenous immunoglobulin or IVIG.

MP usually develops without noticeable symptoms for the first 1 to 3 weeks after exposure. Early-stage diagnosis is difficult because the body doesn’t instantly reveal an infection.

The infection can manifest outside of your lung. If this happens, signs of infection may include the breakup of red blood cells, a skin rash, and joint involvement.

In order to make a diagnosis, your doctor uses a stethoscope to listen for any abnormal sounds in your breathing. A chest X-ray and a CT scan may also help your doctor make a diagnosis.

The risk of contracting MP peaks in the fall and winter months. Close or crowded places make it easy for the infection to transmit from person to person.

To lower your risk of infection, try the following:

  • Get 6 to 8 hours of sleep per night.
  • Eat a balanced diet.
  • Avoid people with symptoms of MP.
  • Practice good hygiene by washing your hands before eating or after interacting with infected people.

According to the Centers for Disease Control and Prevention, M. pneumoniae is the second most common cause of pneumonia-related hospitalizations in adults.

Most people develop antibodies to MP after an acute infection, which protect them from becoming infected again. Patients who have a weak immune system, like those with HIV or people treated with chronic steroids, immunomodulators, or chemotherapy, may be at a higher risk of reinfection.

For others, symptoms should subside 1 to 2 weeks after treatment. A cough may linger, but most cases resolve with no lasting consequences within 4 to 6 weeks.

See your doctor if you continue to experience severe symptoms or if the infection is interfering with your daily life. You may need to seek treatment or a diagnosis for any other conditions that your MP infection might’ve caused.