Tuberculosis — or TB, as it’s commonly called — is a contagious infection that usually attacks the lungs. It can also spread to other parts of the body, like the brain and spine. A type of bacteria called Mycobacterium tuberculosis causes it.
In the 20th century, TB was a leading cause of death in the United States. Today, most cases are cured with antibiotics. But it takes a long time. You have to take meds for at least 6 to 9 months.
How Is It Spread?
Through the air, just like a cold or the flu. When someone who’s sick coughs, sneezes, talks, laughs, or sings, tiny droplets that contain the germs are released. If you breathe in these nasty germs, you get infected.
TB is contagious, but it’s not easy to catch. The germs grow slowly. You usually have to spend a lot of time around a person who has it. That’s why it’s often spread among co-workers, friends, and family members.
Tuberculosis germs don’t thrive on surfaces. You can’t get the disease from shaking hands with someone who has it, or by sharing their food or drink.
How Does Tuberculosis Affect Your Body?
A TB infection doesn’t mean you’ll get sick. There are two forms of the disease:
Latent TB: You have the germs in your body, but your immune system stops them from spreading. That means you don’t have any symptoms and you’re not contagious. But the infection is still alive in your body and can one day become active. If you are at high risk for re-activation — for instance, you have HIV, your primary infection was in the last 2 years, your chest X-ray is abnormal, or you are immunocompromised — your doctor will treat you with antibiotics to lower the risk for developing active TB.
Active TB disease: This means the germs multiply and can make you sick. You can spread the disease to others. Ninety percent of adult cases of active TB are from the reactivation of a latent TB infection.
What Are the Symptoms of TB?
But there are usually signs if you have active TB disease. They include:
- A cough that lasts more than 3 weeks
- Chest pain
- Coughing up blood
- Feeling tired all the time
- Night sweats
- Loss of appetite
- Weight loss
If you experience any of these symptoms, see your doctor to get tested. Get medical help right away if you have chest pain.
Who’s at Risk?
You’re more likely to get TB if you come into contact with others who have it. Here are some situations that could increase your risk:
- A friend, co-worker, or family member has active TB disease.
- You live or have traveled to an area where TB is common, like Russia, Africa, Eastern Europe, Asia, Latin America, and the Caribbean.
- You’re part of a group where TB is more likely to spread, or you work or live with someone who is. This includes homeless people, people with HIV, and IV drug users.
- You work or live in a hospital or nursing home.
A healthy immune system fights the TB bacteria. But if you have any of the following, you might not be able to fend off active TB disease:
- HIV or AIDS
- Severe kidney disease
- Head and neck cancers
- Cancer treatments, such as chemotherapy
- Low body weight and malnutrition
- Medications for organ transplants
- Certain drugs to treat rheumatoid arthritis, Crohn’s disease, and psoriasis
Babies and young children also are at greater risk, because their immune systems aren’t fully formed.
WebMD Medical Reference Reviewed by Sabrina Felson, MD on 3/, 017