Tuberculosis

Tuberculosis is a serious bacterial infection that most often affects the lungs, but it can be treated successfully with antibiotics if diagnosed and treated properly.

Table of contents

• What is tuberculosis?
• What causes tuberculosis?
• How tuberculosis spreads
• Symptoms of tuberculosis
• Who is at higher risk?
• How tuberculosis is diagnosed
• Treatment for tuberculosis
• Preventing tuberculosis

What is tuberculosis?

Tuberculosis (TB) is an illness caused by a bacterial infection (an infection caused by tiny living organisms called bacteria). It most commonly affects the lungs, but TB can also attack other parts of the body, including the kidneys, spine, brain, lymph nodes, bones, and joints.^[1][2]

Not everyone infected with TB bacteria becomes sick. There are two different conditions related to TB. If you have TB bacteria in your body but do not feel sick and have no symptoms, this is called inactive TB or latent TB infection. People with inactive TB cannot spread the disease to others. TB bacteria can live inactive in the body without making you sick, sometimes for your entire life. As many as 13 million people in the United States have latent TB.^[1][2]

When TB bacteria become active and start growing in your body, this is called active TB disease. People with active TB disease feel sick and may be able to spread the bacteria to people they spend time with every day. Without treatment, people with inactive TB can develop active TB disease at any time and become sick. TB can become active if your immune system becomes weakened.^[1][2]

If not treated properly, active TB disease can be fatal. However, TB is both preventable and curable with proper treatment.^[1][4]

What causes tuberculosis?

TB is caused by bacteria called Mycobacterium tuberculosis. In the United States, the majority of TB disease cases in people are caused by Mycobacterium tuberculosis. Other similar bacteria, such as Mycobacterium bovis, can also cause TB disease in people.^[1][2]

How tuberculosis spreads

TB spreads from person to person through the air. When a person with active TB disease of the lungs or throat coughs, sneezes, speaks, sings, or laughs, they release small droplets containing the TB bacteria into the air. If you breathe in these droplets over a long period of time, you can become infected with TB.^[1][4]

You usually have to spend a lot of time in contact with someone who has active TB to catch the disease. TB is more likely to spread in indoor areas or other places with poor air circulation, such as a closed vehicle, than in outdoor areas. People with active TB disease are most likely to spread TB bacteria to people they spend time with every day, such as family members, friends, coworkers, or schoolmates.^[1][2]

TB is not spread by touching, kissing, or sharing food or dishes. It is also very unlikely to be spread from personal items that a person with TB has touched.^[5]

Symptoms of tuberculosis

People with inactive TB do not have symptoms. However, without treatment, they can develop active TB disease and become sick.^[1]

Common symptoms of active TB disease include:^[1][2][4]

• A cough that lasts three weeks or longer
• Chest pain
• Coughing up blood or sputum (thick mucus from deep inside the lungs)
• Weakness or fatigue
• Weight loss
• Loss of appetite
• Chills
• Fever
• Night sweats (heavy sweating during sleep)

Often, these symptoms will be mild for many months. This can lead to delays in seeking care and increases the risk of spreading the infection to others.^[4]

If TB has spread to other parts of your body besides the lungs, you may also have other symptoms, including swollen glands, body aches and pains, swollen joints or ankles, stomach or pelvic pain, constipation, dark or cloudy urine, headache, nausea, feeling confused, a stiff neck, or a rash on the legs, face, or other parts of the body.^[1]

Who is at higher risk?

Anyone can get TB, but certain people have a higher risk of being exposed to TB bacteria or developing active TB disease once infected.^[1]

You have a higher risk of being exposed to TB bacteria if you:^[1][2]

• Were born in or frequently travel to countries where TB is common, including some countries in Asia, Africa, and Latin America
• Live or used to live in large group settings where TB is more common, such as homeless shelters, prisons, or jails
• Recently spent time with someone who has active TB disease
• Work in places where TB is more likely to spread, such as hospitals, homeless shelters, correctional facilities, and nursing homes

You have a higher risk of developing active TB disease once infected if you:^[1][2][5]

• Have a weaker immune system because of certain medications or health conditions such as diabetes, cancer, or HIV
• Were recently infected with TB bacteria
• Are under age 5 or are an older adult
• Inject intravenous drugs or have alcohol use disorder
• Have kidney disease or other chronic (long-term) illnesses
• Have received an organ transplant
• Are on chemotherapy treatment for cancer
• Take medicines that weaken the immune system
• Were not treated correctly for TB in the past

How tuberculosis is diagnosed

Your healthcare provider will order tests if tuberculosis is suspected, if you were likely exposed to a person with active TB disease, or if you have health risks for active TB disease. The provider will do an exam that includes listening to you breathe with a stethoscope (a medical tool for listening to sounds in the body), checking for swollen lymph nodes, and asking you questions about your symptoms.^[10]

Your healthcare team will determine whether a skin test or blood test is the best option for testing for TB infection:^[5][10]

A TB skin test involves injecting a tiny amount of a substance called tuberculin just below the skin on the inside of one forearm. Within 48 to 72 hours, a healthcare worker will check your arm for swelling at the injection site. A positive test indicates you likely have either a latent TB infection or active TB disease. People who had a TB vaccination might get a positive test even if they have no infection.^[10]

A blood test involves taking a sample of blood and sending it to a lab. The lab test finds out whether certain immune system cells can recognize tuberculosis. A positive test shows that you have either a latent TB infection or active TB disease.^[10]

If you have a positive skin or blood test, you may need additional tests to see if the bacteria are actively growing:^[4][5][10]

• A chest X-ray can show irregular patches in the lungs that are typical of active TB disease
• Testing samples of your sputum (the mucus that comes up when you cough) in a lab
• For TB in parts of the body other than the lungs, samples of affected body fluids and tissue can be tested
• Lab tests on lung fluid
• Computed tomography (CT) scans

Treatment for tuberculosis

Both inactive TB and active TB disease can be treated. It is important to take and finish all TB medicines exactly as your healthcare provider recommends. Completing treatment for inactive TB and active TB disease can protect yourself, your family and friends, and your community.^[9]

Healthcare providers treat both active and inactive tuberculosis with specific kinds of antibiotics (medicines that kill bacteria). You will likely need to take a combination of medications to get rid of the infection. You will have to take these medications for a long time—several months. You must take them exactly as your provider prescribes to get rid of all the bacteria. It is very important to finish your entire prescription, even if you feel better.^[2][9]

Treatment for inactive TB can take three, four, six, or nine months depending on the treatment plan. The treatment plans for inactive TB use different combinations of medicines that may include isoniazid, rifampin, and rifapentine.^[9]

Treatment for active TB disease can take four, six, or nine months depending on the treatment plan. The treatment plans for active TB disease use different combinations of medicines that may include ethambutol, isoniazid, moxifloxacin, rifampin, rifapentine, and pyrazinamide.^[9]

A treatment plan (also called treatment regimen) for inactive TB or active TB disease includes the types of TB medicines to take, how much TB medicine to take, how often to take the TB medicines, how long to take the medicines, how to monitor yourself for any side effects of your TB medicine, and the healthcare providers who will support you through the treatment process. You and your healthcare provider will discuss which treatment plan is best for you.^[9]

Directly observed therapy (DOT) is the best way to ensure that you will be cured of TB. With DOT, a healthcare worker will bring your TB medicine to you and will watch you take it. This ensures that you take the needed medicine on schedule.^[9]

During your treatment, you will see your doctor for tests to see how the medicines are working. You will start to feel better after taking your medicine for a few weeks. However, do not go back to work or school until your doctor tells you it is okay.^[1]

If you have drug-resistant TB disease, where the TB bacteria are resistant to certain medicines, treatment is more complicated. There are several treatment plans for drug-resistant TB disease depending on what medicines the TB bacteria are resistant to. Treating and curing drug-resistant TB disease should be done by a TB medical expert. People with drug-resistant TB disease must be treated with special medicines.^[9]

Preventing tuberculosis

People with inactive TB can take treatment to prevent the development of active TB disease. People with active TB disease of the lungs or throat may need to take steps to prevent spreading TB bacteria to others.^[18]

If you have been diagnosed with active TB that can spread to other people, you may be asked to stay in home isolation. This means you avoid contact with other people to help stop the spread. Young children and people with weak immune systems are at the highest risk of getting sick. Until your doctor tells you that you can no longer spread TB, you should:^[19][23]

• Remain in your home and avoid contact with others
• Always cover your mouth and nose when you cough or sneeze
• Spend only a short time in rooms that other people use, like the bathroom or kitchen
• Do not have visitors, especially children and people with weak immune systems
• Do not go to work, school, your place of worship, or public places like stores
• Do not use public transportation including buses, taxis, trains, and airplanes
• Wear a mask when you are around other people or when you go to medical appointments
• If possible, use a fan or open windows in your home to move the air around
• You may go outside in the open air without your mask

If you live with other people, ask them to be tested for TB.^[19]

There is a vaccine for tuberculosis called the BCG vaccine. It is recommended for some people who are at higher risk of catching TB or getting seriously ill from it.^[15]