Tuberculosis (TB): Definition and Symptoms

Tuberculosis (TB) is a potentially serious infectious disease primarily affecting the lungs but can involve other parts of the body. Despite being preventable and curable, TB remains a major global health concern, particularly in low-income countries. This article delves into the definition and symptoms of TB to raise awareness and promote early diagnosis.

Definition of Tuberculosis

TB is caused by the bacterium Mycobacterium tuberculosis. It spreads through the air when an infected person coughs, sneezes, or talks, releasing microscopic droplets containing the bacteria. Although TB primarily affects the lungs (pulmonary TB), it can also target other organs, including the brain, spine, kidneys, and lymph nodes, in a condition known as extrapulmonary TB.

TB infection can be categorized into two stages:

1. Latent TB Infection
   In this stage, the bacteria remain inactive in the body and cause no symptoms. However, latent TB can become active later, especially if the immune system weakens. Approximately one-quarter of the world's population has latent TB.

2. Active TB Disease
   This is when the bacteria multiply and cause symptoms. Active TB can occur soon after infection or years later. Without treatment, active TB can be fatal.

Symptoms of Tuberculosis

The symptoms of TB vary depending on whether it is pulmonary or extrapulmonary and the organ involved. Below are the key symptoms associated with TB:

Pulmonary TB Symptoms

Pulmonary TB is the most common form of the disease, primarily affecting the lungs. Its symptoms include:

1. Persistent Cough
   A cough lasting more than three weeks is one of the hallmark symptoms. It may initially be dry but can progress to producing phlegm or blood.

2. Chest Pain
   Pain in the chest or difficulty breathing may occur due to inflammation or damage to the lung tissue.

3. Coughing Up Blood (Hemoptysis)
   In advanced cases, the patient may cough up blood, indicating significant lung damage.

4. Shortness of Breath
   Difficulty breathing can result from severe lung involvement or damage caused by the infection.

Systemic Symptoms of TB

TB can affect the entire body, leading to general symptoms such as:

1. Unexplained Weight Loss
   Rapid weight loss without dietary changes is a common symptom, often due to the body’s immune response and the bacteria consuming energy.

2. 
   Fatigue
   Persistent tiredness and weakness, even after adequate rest, are common in TB patients.

3. Fever
   Low-grade fever that fluctuates is frequently observed, especially in the evenings.

4. Night Sweats
   Profuse sweating during sleep is another hallmark symptom, often accompanied by fever.

5. Loss of Appetite
   A significant decrease in appetite may accompany other systemic symptoms.

Extrapulmonary TB Symptoms

When TB spreads beyond the lungs, the symptoms depend on the affected organ:

1. Lymph Nodes
   Swelling of lymph nodes, often in the neck, which may become tender or form abscesses.

2. Spine (Pott’s Disease)
   Back pain or stiffness, along with potential deformity or paralysis in severe cases.

3. Kidneys
   Symptoms may include blood in the urine or flank pain.

4. Brain (Tuberculous Meningitis)
   Headaches, confusion, neck stiffness, and seizures may develop if the brain is affected.

5. Abdomen
   Abdominal pain, swelling, and difficulty eating can occur if the digestive system is involved.

Who is at Risk?

While anyone can develop TB, certain groups are at higher risk, including:

• People with weakened immune systems (e.g., HIV/AIDS patients).
• Those living in crowded or poorly ventilated conditions.
• Healthcare workers frequently exposed to TB patients.
• Individuals with chronic illnesses such as diabetes or malnutrition.

Conclusion

Tuberculosis is a serious yet preventable and treatable disease. Recognizing its symptoms—whether pulmonary or systemic—is crucial for early diagnosis and effective treatment. If you or someone you know exhibits signs of TB, seek medical attention promptly. Timely intervention can save lives and prevent the spread of this infectious disease.