What Is Tuberculosis?

Tuberculosis (TB) is a contagious infectious disease caused by Mycobacterium tuberculosis that most commonly affects the lungs but can spread to other parts of the body. TB spreads through the air when a person with active pulmonary TB coughs, speaks, or breathes, releasing bacteria that others can inhale.

TB can exist as either latent infection, where bacteria are present but inactive, or active disease, where symptoms develop and the person may be contagious. Despite being preventable and treatable, TB remains a global and occupational health concern, particularly for healthcare workers and individuals in high-risk or congregate environments. According to the World Health Organization (WHO), TB caused an estimated 1.3 million deaths worldwide in 2022, making it one of the leading infectious causes of death globally. 

In this article, we’ll cover TB symptoms, causes, treatment, prevention strategies, and why tuberculosis training remains essential today.

What Is Tuberculosis (TB)?

Tuberculosis is an infectious disease caused exclusively by Mycobacterium tuberculosis, a slow-growing bacterium that primarily infects the lungs. When TB affects the lungs, it is known as pulmonary TB, which is the most common and contagious form of the disease.

TB can also affect areas outside the lungs, known as extrapulmonary TB, involving organs such as the lymph nodes, kidneys, spine, brain, or joints. Another critical distinction is between latent TB infection (LTBI) and active TB disease. People with latent TB do not feel sick and cannot spread the disease, but they carry bacteria that can become active later, especially if the immune system weakens. This distinction matters because latent TB still requires treatment to prevent future disease and transmission.

Types of Tuberculosis Infections

Tuberculosis presents in several main forms, each with different clinical and public health implications.

• Pulmonary TB: The most common form and primarily affects the lungs. It is the main source of TB transmission because bacteria are expelled into the air during coughing or breathing.
• Extrapulmonary TB: Occurs when the infection spreads beyond the lungs. Common sites include lymph nodes, bones and joints, kidneys, the central nervous system, and the heart. While serious, extrapulmonary TB is usually not contagious unless it also involves the lungs.
• Latent TB infection: Occurs when the immune system contains the bacteria without eliminating them. People with latent TB have no symptoms and are not infectious, but the CDC estimates that about 5–10% of infected individuals will develop active TB during their lifetime if untreated. 

Tuberculosis Symptoms to Watch For

TB symptoms vary depending on the type of infection, age, and overall health. 

Adults with an active pulmonary TB infection will have symptoms that can include:

• A cough lasting longer than 3 weeks
• Chest pain
• Coughing up blood
• Fatigue
• Night sweats
• Chills
• Fever
• Loss of appetite
• Weight loss

Extrapulmonary infections can lead to other symptoms based on the part of the body infected. For example, a kidney infection may produce blood in the urine, while a skeletal infection may produce back pain. Even once a TB infection is cleared, there can be lasting complications like joint damage, lung damage, liver or kidney problems, pericardial inflammation, or damage to previously infected tissues.

What Causes Tuberculosis and Who Is at Risk? 

Tuberculosis is caused only by infection with Mycobacterium tuberculosis. However, certain factors can put you at greater risk of contracting the disease.

You’re more likely to be exposed to someone with an active TB infection if you:

• Spend time with someone who has active TB
• Live or travel to areas where TB is common (Russia, Africa, Eastern Europe, Asia, Latin America or the Caribbean)
• Have contact with people who are unhoused, HIV positive, inject drugs, are in jail or prison
• Work in a hospital, nursing home, or see patients at high risk of TB

You’re more likely to develop active TB after exposure if you:

• Are a smoker
• Are under 5, aged 15-25, or over 65
• Have HIV, AIDS, diabetes, advanced kidney disease, or head/neck cancer
• Are underweight or have poor nutrition
• Are undergoing chemotherapy
• Take immunosuppressants for an organ transplant or autoimmune disease

How Is Tuberculosis Treated?

Tuberculosis is treated with antibiotics, but treatment requires a much longer course than most bacterial infections. Latent TB infection is typically treated for about 3 months using one or more antibiotics, while active TB disease usually requires 6 to 9 months of combination antibiotic therapy.

Strict adherence to treatment is critical. Stopping medications early can allow TB bacteria to survive and become drug-resistant. The CDC warns that multidrug-resistant TB (MDR-TB) is harder to treat, more expensive, and associated with worse outcomes than drug-susceptible TB. 

How Tuberculosis Spreads 

Tuberculosis primarily spreads through respiratory droplets from an individual with an active pulmonary infection when they cough, sneeze, or vocalize. If someone has a tuberculosis infection that doesn’t include their lungs, it’s usually not contagious.

Mycobacterium tuberculosis bacteria can’t survive long on surfaces outside the human body, so the transmission has to be direct and face-to-face.

If someone close to you develops TB, if you spend time around populations at risk for TB, or if you travel to an area where TB thrives, you need to take measures to protect yourself from becoming infected. That includes:

• Avoiding close contact with people who have or may have an active TB infection.
• Wearing a surgical or N95 mask when you can’t avoid close contact, or you’re in crowded places.
• Wash your hands regularly and avoid touching any part of your face.

Since most healthy adults are asymptomatic during the primary infection and go into a latent period, you could have a TB infection and not know it for months. That’s why it’s important to get tested for TB after potential exposure. Treating an infection before you’re symptomatic minimizes the likelihood of passing it to others.

If you do end up with an active TB infection, you have a serious responsibility to avoid spreading it to others during the first 2 to 3 weeks while you’re contagious. You can do this by:

• Limiting contact with others. This includes staying home, isolating from members of your household, and sleeping alone while you have an active infection.
• Covering your mouth when you sneeze and cough.
• Wearing a surgical or N95 mask when you can’t avoid being around other people.
• Keeping the spaces you occupy well-ventilated.

It’s also important that you take your antibiotics diligently and continue until a doctor tells you it’s okay to stop. If you skip too many doses, a latent infection can become contagious again. If you discontinue your medication early, some bacteria will remain in your system, and you could have another flare-up that makes you contagious later. Worse, you’ll be at risk of passing on drug-resistant tuberculosis instead.

How to Prevent Tuberculosis Infection and Transmission

After potential exposure, prevention focuses on early testing, medical evaluation, and treatment of latent TB to stop progression to active disease. TB blood tests or skin tests are commonly used, especially for healthcare workers and high-risk populations.

During active TB infection, preventing transmission requires isolation, mask use, proper ventilation, and strict adherence to antibiotic treatment. Completing the full course of medication is essential to prevent relapse, resistance, and further spread.

Why Tuberculosis Training Is Important for Healthcare Workers

Healthcare workers face an increased risk of TB exposure due to close contact with patients and high-risk populations. The CDC emphasizes routine TB education to support early recognition, appropriate infection control measures, and workforce safety.

Training helps reduce occupational risk, improves compliance with workplace health policies, and ensures workers understand screening, prevention, and response protocols. Ongoing education is a key component of protecting both healthcare staff and patients.

Online Tuberculosis Prevention Training

Another way to prevent the spread of TB is to educate people who are at risk of contracting it. That’s why the CDC says healthcare workers need annual training on TB risk and prevention. This helps you stay fresh on CDC infection control guidelines and ways to protect yourself.

Online TB courses like ours make meeting these requirements easy and convenient. Courses are self-paced and can be taken from anywhere with an internet connection. This helps you make mandatory training work around your schedule, not the other way around.

Enroll today!