Tuberculosis, or TB, is a serious contagious disease caused by bacteria that spread from person to person through the air. The bacteria spread easily like the cold or flu, especially in crowded places with poor airflow. The longer you breathe these germs, the more likely you are to become infected.

Older couple walkingOlder couple walkingProvider with stethoscope examining older woman

What are the risk factors for developing tuberculosis?

Anyone can get tuberculosis. But you may be at greater risk if you:

  • Are a health care worker.
  • Are an older adult or a young child, as you have weaker immune response.
  • Have a weakened immune system because you have an autoimmune disorder, are receiving certain cancer treatments or are on medications like steroids
  • Have a low body weight.
  • Have Human Immunodeficiency Virus (HIV).
  • Have first developed latent TB within the past 2-5 years.
  • Have not received appropriate treatment for latent TB.
  • Have close contact with someone who has untreated active TB of the lungs.
  • Have substance abuse problems.
  • Have other health conditions such as diabetes, scoliosis, severe kidney disease, or head and neck cancer.
  • Inject recreational drugs with unsanitary equipment, such as sharing needles.
  • Live in a residential facility, such as homeless shelters, nursing homes or prison
  • Recently had an organ transplant.
  • Smoke or are in frequent contact with secondhand smoke.
  • Travel to or come from a country where there are high rates of TB infections, such as India and parts of Asia, Africa and Eastern Europe.

Inactive and active tuberculosis

Inactive tuberculosis (latent TB infection)

An estimated 13 million people have latent TB in the United States, according to the CDC (Centers for Disease Control and Prevention).

If you’ve been diagnosed with inactive TB, this means that you:

  • Can only be diagnosed with a TB test.
  • Can’t spread the infection to others.
  • Have live TB bacteria in your lungs, but the germs have been sealed off, much like a scab covers a wound. As a result, the bacteria cannot replicate and cause active disease, so you won’t have symptoms or feel sick.
  • Generally need medicine to keep the infection from becoming active at some future time. Without medication, latent infections can become active in 5–10% of people with the infection.

Active tuberculosis (TB disease)

An estimated 90% of adults with active TB have developed it from untreated latent infections.

If you’ve been diagnosed with active TB, it means that you:

  • Can spread the active infection to others.
  • Have symptoms of TB, especially symptoms in your lungs and throat. There may be other symptoms from the part of the body affected. You’re likely to feel very sick.
  • Must take medicine to help cure the disease. Treatment takes at least 6 months. TB is sometimes hard to cure.

Symptoms of tuberculosis

Symptoms for tuberculosis vary from person to person, depending on the severity and type of infection. Some people may not experience symptoms or feel sick, especially if they have inactive tuberculosis.

Those with active TB disease, though, may experience the following symptoms:

  • Chills.
  • Fever.
  • Lasting cough that produces phlegm or mucus.
  • Loss of appetite.
  • Nausea and vomiting.
  • Night sweats.
  • Severe tiredness (fatigue).
  • Swollen glands and lymph nodes.
  • Weight loss.

Symptoms of pulmonary tuberculosis mainly affect the lungs, and include:

  • Breathlessness.
  • Chest pain.
  • Lasting cough that produces phlegm and blood.

There may be other symptoms from the part of the body affected by TB. This is more common in people with weakened immune systems.

Extrapulmonary TB can cause the following symptoms:

  • Abdominal pain.
  • Bone or joint pain.
  • Confusion.
  • Persistent headaches.
  • Swollen lymph nodes.
  • Seizures.

When to call your health care provider

Call your health care provider right away if you have any of the following:

  • A fever of 100.4°F (38°C) or higher.
  • Chest pain or shortness of breath.
  • Increased coughing or coughing up blood.
  • Night sweats that get worse or keep coming back.
  • Trouble breathing.

Also call your provider if you’re taking TB medicine and think you’re having side effects. These include skin rash, yellowing of the eyes or stomach problems.

How is tuberculosis diagnosed?

The only way to diagnose tuberculosis is through a variety of lab testing, since latent TB has no symptoms.

However, if you suspect you have active TB, your healthcare provider will start by taking your health history, perform a physical exam to check your lymph nodes and lung function, and evaluate your symptoms. They may also ask you the following questions:

  • Have you recently spent time with someone who has or is at risk of developing TB?
  • Do you work in an environment where TB may be present?
  • Have you recently visited a country with higher rates of TB?

Your doctor will then perform one or more of the following tests to determine if you are infected with the tuberculosis bacteria:

  • Skin test (Mantoux Tuberculin skin test). A testing solution called tuberculin is injected just under the skin on your arm. This is done to see if there’s a reaction such as a hard, red bump called a wheal. You’ll need to return to the office in 2 or 3 days to have your arm checked. Be sure to keep the appointment, as you’ll learn the test results during this visit. If you are infected with TB, your immune system will react to the injection after the skin test. This test cannot determine which type of TB you have.
  • Blood test (Interferon-Gamma Release Assays or IGRAs). A small amount of blood is drawn and sent to a lab for testing. The lab will measure the response when TB proteins mix with the sample to determine if you have the infection. This test cannot determine which type of TB you have.
  • Imaging tests. If you have a TB infection, imaging tests, such as a chest X-ray can determine if the infection is active or latent by monitoring changes in your lungs.
  • Sputum sample (Acid-fast bacillus or AFB). Your provider may take a sample of the mucus that comes up when you cough (sputum) for testing to determine the type of TB you have.
  • Biopsy. Your provider may do a biopsy of a swollen gland or other body part. The sample is sent to a lab and tested for TB bacteria. Knowing the type of bacteria causing your illness helps your health care providers choose the right medicine to treat the disease.

What do the test results mean?

A negative result usually means that your body is free of TB bacteria. Sometimes the test can be negative, even in someone with TB infection or active TB (false negative).

A positive result indicates that you’ve been exposed to the germs that cause Tuberculosis. You may have an inactive or active infection, and will need further evaluation to confirm the type.

Treatments for tuberculosis

If detected early on, tuberculosis can be treated and cured with antibiotics. Your healthcare provider will determine your course of medical treatment based on your age and overall health, the location of your initial infection, what type of TB you have and if the strain of bacteria is resistant to drugs (multidrug-resistant TB).


Antibiotics are the only effective treatment for both inactive and active TB. If you have active TB, you’ll be prescribed more medicines for a longer time – at least 6 months – to help cure the disease.

You’ll likely begin feeling better shortly after starting treatment. But even if you’re feeling better it’s important to keep taking all the medicine you’ve been prescribed. This is the only way to cure the disease. Not taking all the medicine means you won’t get well and can keep spreading TB germs to others.

Sometimes TB is drug-resistant. This means it doesn’t respond to one or more of the usual medicines for TB. Drug-resistant strains are harder to cure. It requires different second-line drug prescriptions and often longer treatment.

Depending if other parts of your body than your lungs are affected, your doctor may also prescribe corticosteroids such as prednisone to alleviate symptoms.


Children in certain parts of the world often get vaccinated against tuberculosis with a BCG vaccine. However, experts in the United States do not recommend the vaccine for most people unless they are at a high risk of developing tuberculosis. The vaccine may not be recommended due to low risk of infection in the country. In some instances, the vaccine can also interfere with future tuberculin skin tests, and doesn’t always protect against infection.

Consult with your doctor if you are at high risk of developing tuberculosis, and whether or not you should receive the vaccine.

Directly observed therapy (DOT) treatment

During treatment, you may be offered or be required to take part in a program called DOT (directly observed therapy). In this program, a nurse, healthcare worker or individual (such as a family member) gives you the antibiotic and watches you take it. Having someone supervise your treatment makes it easier for you to manage your medication, stick to your treatment schedule and notice any side effects or problems early.

During treatment for tuberculosis

  • Take all the medicine as directed, even when you start feeling better. You’ll take the medicine for 6 months or longer. Sticking to this schedule takes patience. But stopping complete treatment early means your symptoms may come back. It may also lead to drug-resistant TB due to inadequate treatment.
  • Get plenty of rest and eat healthy meals. A nutritious diet full of fresh fruits and vegetables helps the body fight infection.
  • Check with your healthcare provider before using any over-the-counter (OTC) medicines that haven’t been prescribed. OTCs can interact with your prescription medicines. If you’re taking birth control pills, you may need to also use a backup method of birth control, as some TB medicines may make the pill less effective.
  • You might need to limit your activity so you don’t get too tired.
  • Keep your medical appointments. You’ll need to be checked often to make sure that your medicine is working and you’re getting better.

Frequently asked questions (FAQs) about tuberculosis

What causes tuberculosis, and how does it spread?

Tuberculosis is not caused by a virus. Instead, it is caused by a bacteria called Mycobacterium tuberculosis (M. tuberculosis). The bacteria typically affects the lungs, making it more contagious, but can also attack other parts of the body.

Tuberculosis bacteria is most often spread person to person. It is released into the air when someone with the active tuberculosis coughs or sneezes. The bacteria spread easily like the cold or flu, especially in crowded places with poor airflow. The longer you breathe these germs, the more likely you are to become infected.

However, tuberculosis cannot survive outside the body. So it cannot be spread by shaking hands, sharing food or drink, or touching surfaces that an infected person has touched.

Can tuberculosis cause any complications?


If left untreated, tuberculosis can lead to death. If it spreads through a person’s entire body, the bacterial infection can lead to serious health complications including heart diseases, metabolic dysfunction and other severe problems. Tuberculosis can also cause sepsis, which is when your body has an extreme reaction to infection and damages your tissues. This can be fatal if not promptly treated.

The following complications can also occur, which may result in fatalities in some instances:

  • Damage to the bones, brain, lymph nodes or spinal cord.
  • Inflammation in the tissues around your heart.
  • Joint damage.
  • Kidney or liver problems.
  • Lung damage.
What are some ways to prevent the spread of TB?

If you have active TB of the lungs or throat, you should:

  • Ask family, friends and the people you work with to get tested. Active TB can spread to other people.
  • Don’t have close contact with people until your healthcare provider says it’s OK.
  • Wash your hands often, especially after coughing. Use soap and clear, running water and scrub your hands for at least 20 seconds.
  • Use a tissue to cover your mouth when you cough. If you don’t have a tissue, cough into your elbow, not your hand. Wash your hands after you cough or sneeze.
  • Wear a mask, if you’ve been told to do so, when you go out in public or visit your healthcare provider.
  • Use a plastic bag to throw away old tissues and other supplies.
  • Make sure you are in a well-ventilated room.
How can I help someone who has TB with their treatment?

TB is a serious illness that can take a long time to cure. If you have a family member or friend with TB, you can help by reminding your loved one to:

  • Take TB medicines at the same time every day (they’re best taken with water, milk or juice 30 minutes before meals or at bedtime).
  • Keep all follow-up appointments (you can help by driving or arranging for a ride).
  • Get plenty of rest.
  • Eat healthy meals.


Center for Disease Control and Prevention (CDC). Basic TB Facts (

MedlinePlus: National Library of Medicine. Tuberculosis (

National Institute of Allergy and Infectious Diseases (NIAID). Tuberculosis (