Tuberculosis (TB) Causes, Symptoms, Treatment Vector

Tuberculosis (TB): Causes, Symptoms, Treatment (2024)

by | Updated: May 4, 2024

Tuberculosis (TB) is a potentially serious infectious disease that mainly affects the lungs.

Caused by the bacterium Mycobacterium tuberculosis, TB can also impact other parts of the body, including the kidneys, spine, and brain. 

This article provides an overview of tuberculosis, including its transmission, symptoms, diagnosis, treatment, and the global efforts to combat this resilient disease.

What is Tuberculosis?

Tuberculosis (TB) is a contagious bacterial infection caused by Mycobacterium tuberculosis, primarily affecting the lungs. It spreads through airborne particles from coughs or sneezes. Symptoms include persistent cough, fever, night sweats, and weight loss. Treatment involves long-term antibiotic regimens. TB remains a major global health issue, particularly in developing countries.

Tuberculosis lungs vector illustration


The symptoms of tuberculosis can vary depending on the stage and severity of the infection.

Common symptoms include:

  • Persistent cough (lasts for more than three weeks and often produces phlegm, which may be bloody)
  • Chest pain (or pain with breathing or coughing)
  • Unintentional weight loss
  • Fatigue and weakness
  • Fever (often with night sweats)
  • Chills
  • Loss of appetite

Note: In some cases, if the infection spreads beyond the lungs, symptoms specific to the affected body part may occur. For example, TB of the spine may cause back pain, and TB in the kidneys might cause blood in the urine.


Diagnosing tuberculosis typically involves a combination of medical history, physical examination, and specific tests:

  • Skin Test (Mantoux Tuberculin Skin Test): A small amount of a substance called PPD tuberculin is injected just below the skin of your inside forearm. After 48-72 hours, a healthcare professional checks the area for a reaction.
  • Blood Tests (Interferon-gamma release assays or IGRAs): These tests measure the immune system’s response to TB bacteria. Examples include the QuantiFERON-TB Gold Plus test and the T-SPOT.TB test.
  • Chest X-ray or CT Scan: These imaging tests are used to check for abnormalities in the lungs.
  • Sputum Tests: If TB is suspected in the lungs, samples of your sputum (the mucus you cough up) are collected and tested for TB bacteria.
  • Additional Tests: If TB is suspected outside the lungs (extrapulmonary TB), samples from the affected area may be tested.

Note: A positive skin or blood test doesn’t necessarily mean active TB. It may indicate latent TB, where the bacteria remain in the body in an inactive state and cause no symptoms. Active TB, especially drug-resistant strains, requires more complex treatments.


Treatment for tuberculosis is a lengthy process that typically involves a combination of medications over several months.

The specifics of the treatment can vary depending on whether the TB is latent or active, and whether it is drug-resistant.

  • Latent TB Treatment: For latent TB (where the bacteria are present but inactive), the treatment usually involves taking one or two types of TB drugs to prevent the development of active TB. Common options include Isoniazid, Rifampin, or a combination of Isoniazid and Rifapentine. These treatments can last for 3 to 9 months.
  • Active TB Treatment: Active TB, particularly in the lungs, requires a more aggressive treatment strategy. The standard treatment is a 6-month course of a combination of antibiotics. The most common regimen includes Isoniazid, Rifampin, Ethambutol, and Pyrazinamide for the initial two months, followed by Isoniazid and Rifampin for the next four months. The dosages and length of treatment might be adjusted based on the patient’s response and any drug resistance.
  • Monitoring and Support: During treatment, patients are closely monitored for side effects and to ensure the effectiveness of the medication. Regular medical appointments and tests are crucial.
  • Drug-resistant TB: Treatment for drug-resistant TB is more complex and can last for up to 24 months. It involves a combination of several antibiotics, some of which may have more severe side effects.
  • Adherence to Treatment: It is vital for patients to strictly adhere to their TB treatment regimen. Incomplete or inconsistent treatment can lead to drug resistance, making the TB more difficult to treat.

Note: Directly observed therapy (DOT) may be recommended, where a healthcare provider administers the medication and observes the patient taking each dose, to ensure compliance and completion of the treatment course.

Risk Factors and Prevention

Risk Factors for tuberculosis include:

  • Close Contact with TB Patients: Prolonged exposure to someone with active TB significantly increases the risk of infection.
  • Weakened Immune System: People with HIV/AIDS, diabetes, or conditions that affect the immune system are more susceptible. Certain medications, like corticosteroids or drugs for organ transplant recipients, can also weaken the immune system.
  • Living or Traveling in High-Risk Areas: Regions with high rates of TB, such as parts of Africa, Asia, Eastern Europe, and Russia, pose a greater risk.
  • Substance Abuse: Alcoholism and drug abuse can weaken the immune system, increasing susceptibility.
  • Healthcare Work: Regular contact with TB patients increases healthcare workers’ risk.
  • Poor Living Conditions: Overcrowded and unsanitary living conditions can facilitate the spread of TB.
  • Malnutrition and Poor General Health: A poorly nourished body is more vulnerable to TB.

Prevention strategies for tuberculosis include:

  • Vaccination: The Bacille Calmette-Guerin (BCG) vaccine can prevent severe forms of TB in children but is less effective in adults.
  • Reducing Transmission: Wearing masks, ventilating rooms, and practicing cough etiquette can reduce the spread.
  • Screening and Treatment of Latent TB: Identifying and treating latent TB infection, especially in high-risk individuals, can prevent the development of active TB.
  • Health Education: Educating communities about TB, its transmission, symptoms, and treatment is crucial.
  • Regular Health Check-ups: For those in high-risk occupations or living conditions, regular screenings are important.
  • Healthy Lifestyle: A balanced diet, regular exercise, and avoiding tobacco and excessive alcohol can strengthen the immune system.
  • Protective Measures in Healthcare Settings: Using personal protective equipment, implementing infection control practices, and regular health screenings for healthcare workers.

Note: Implementing these strategies, especially in high-risk areas and populations, is essential for reducing the incidence of TB.

Active vs. Latent Tuberculosis

Active and latent tuberculosis represent two distinct states of the disease caused by the same bacteria, Mycobacterium tuberculosis.

Understanding the differences between them is crucial for effective treatment and prevention:

Latent Tuberculosis

  • Infection State: In latent TB, the bacteria are present in the body but are inactive. They cause no symptoms and are not contagious.
  • Symptoms: There are no symptoms of disease in latent TB.
  • Diagnosis: Latent TB is usually diagnosed through a skin test (Mantoux tuberculin skin test) or blood tests (like the IGRA – Interferon Gamma Release Assay).
  • Treatment: The usual treatment involves taking one or two types of antibiotics to prevent the bacteria from becoming active. Treatment duration is shorter compared to active TB, typically ranging from 3 to 9 months.
  • Risk of Activation: People with latent TB have a risk of the infection becoming active, especially if their immune system weakens.

Active Tuberculosis

  • Infection State: Active TB means the bacteria are multiplying and causing symptoms. This form of TB is contagious and can spread to others, especially if it affects the lungs.
  • Symptoms: Symptoms include a persistent cough, chest pain, coughing up blood, fatigue, weight loss, fever, and night sweats.
  • Diagnosis: Active TB is diagnosed using a combination of methods including a chest X-ray, sputum test (where the mucus coughed up is examined), and sometimes CT scans.
  • Treatment: Treatment is more intensive, involving a combination of antibiotics taken for at least 6 months. The standard regimen includes Isoniazid, Rifampin, Ethambutol, and Pyrazinamide.
  • Contagiousness: Patients with active TB, especially in the lungs or throat, can spread the bacteria to others through airborne particles from coughs or sneezes.

Note: Understanding these differences is essential for appropriate management and control of TB. While latent TB does not pose immediate health risks to the individual or their community, without proper treatment, it can progress to the more dangerous active form.

Global Impact of Tuberculosis

Tuberculosis (TB) remains one of the world’s deadliest infectious diseases, particularly impacting low- and middle-income countries.

Despite being preventable and curable, TB causes approximately 1.5 million deaths globally each year.

It disproportionately affects vulnerable populations, including those with HIV/AIDS, refugees, and those living in crowded conditions.

TB’s impact extends beyond health, influencing economic stability and productivity, as it primarily affects people in their most productive years.

The global fight against TB has been challenged by drug-resistant strains and the COVID-19 pandemic, which disrupted healthcare services and TB control efforts, underscoring the need for strengthened public health systems and sustained international focus.

FAQs About Tuberculosis

Is Tuberculosis Airborne or Droplet?

Tuberculosis (TB) is an airborne disease. It spreads through tiny airborne particles, known as droplet nuclei, which can be released into the air when a person with active pulmonary TB coughs, sneezes, speaks, or sings.

These particles can remain suspended in the air for several hours, potentially infecting others who inhale them.

Is Tuberculosis a Virus?

No, tuberculosis is not caused by a virus. It is caused by a bacterium known as Mycobacterium tuberculosis.

This distinguishes TB from viral infections and requires different types of treatment, typically involving antibiotics rather than antiviral medications.

What is the Life Expectancy of Tuberculosis?

The life expectancy of individuals with tuberculosis varies depending on several factors, including the promptness of diagnosis, the effectiveness of treatment, and the presence of any drug-resistant strains of the TB bacteria.

With proper treatment, most people with TB can expect a normal life expectancy. However, untreated or inadequately treated TB can be fatal.

Can Tuberculosis Be Cured?

Yes, tuberculosis can be cured with proper treatment. The standard treatment for TB is a course of antibiotics taken for at least six months.

The treatment regimen must be followed closely and completed to ensure effectiveness and prevent the development of drug-resistant TB.

It’s important for patients to adhere strictly to their treatment plan prescribed by a healthcare provider.

What is the Mantoux Tuberculin Skin Test?

The Mantoux tuberculin skin test is a diagnostic tool for tuberculosis.

It involves injecting a small amount of a substance called purified protein derivative (PPD) tuberculin into the skin of the lower arm.

After 48 to 72 hours, the injection site is examined for a reaction.

A raised, hard area or swelling may indicate TB infection, but further tests are usually required to confirm active TB.

Does Tuberculosis Ever Go Away?

Tuberculosis can go away with proper treatment. However, if left untreated, TB can be a chronic, lifelong condition or can lead to death.

Even with latent TB, where the bacteria are inactive and do not cause symptoms, treatment is recommended to prevent the bacteria from becoming active later.

Is Tuberculosis Deadly?

Tuberculosis can be deadly if not properly treated. It’s one of the top causes of death from infectious diseases worldwide.

However, with appropriate and timely treatment, the majority of TB cases can be cured, significantly reducing the risk of death.

Should Tuberculosis Patients Be Isolated?

Patients with active tuberculosis should be isolated to prevent the spread of the disease, especially in the initial phase of treatment.

Isolation typically continues until a healthcare provider confirms that the patient is no longer contagious.

This duration depends on the patient’s response to treatment and the type of TB.

Guidelines vary by region and healthcare setting, but generally, isolation is not required once the patient is on effective treatment and showing improvement.

Can Tuberculosis Cause Cancer?

Tuberculosis does not directly cause cancer.

However, chronic inflammation and scarring from long-standing TB, especially in the lungs, may increase the risk of developing certain types of lung cancer.

This risk is relatively low and generally occurs in cases of long-term, repeated, or poorly treated TB infections.

Can You Have Tuberculosis and Not Know It?

Yes, it’s possible to have tuberculosis and not know it, particularly in the case of latent TB. In this state, the TB bacteria are present in the body but are inactive and cause no symptoms.

People with latent TB are not contagious and may remain unaware of the infection unless tested. This is why screening for TB in high-risk populations is important.

When to See a Doctor?

You should see a doctor if you experience symptoms of tuberculosis, such as a cough that lasts more than three weeks, unexplained weight loss, night sweats, fever, and fatigue.

It’s also important to seek medical attention if you’ve been in close contact with someone who has active TB, or if you have a weakened immune system and are at higher risk for TB.

Remember: Early diagnosis and treatment are crucial for effective management of the disease.

Final Thoughts

Tuberculosis is a manageable but serious disease. With proper treatment and precautions, TB’s impact can be significantly reduced.

Ongoing research, improved healthcare policies, and global cooperation are essential to combat this ancient yet still prevalent disease.

John Landry, BS, RRT

Written by:

John Landry, BS, RRT

John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.


  • Adigun R, Singh R. Tuberculosis. [Updated 2023 Jul 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023.
  • Centers for Disease Control and Prevention. (n.d.). Directly observed therapy. Centers for Disease Control and Prevention. 2023.
  • Centers for Disease Control and Prevention. (2020, April 6). Tuberculosis. Centers for Disease Control and Prevention. 2023.

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