Tuberculosis – Symptoms and Causes

Overview

Tuberculosis (TB) is a bacterial infection that mainly affects the lungs. However, it can also spread to other parts of the body, such as the brain and spine.

TB is caused by the bacteria Mycobacterium tuberculosis. When a person with TB coughs, sneezes, or spits, the bacteria can spread through the air. If you breathe in these bacteria, you can become infected.

Once infected, the bacteria can stay dormant in your body for years. However, if your immune system becomes weak, the bacteria can become active. When this happens, you may start to show symptoms of TB.

The symptoms of TB can vary depending on which part of the body is affected. For example, pulmonary TB affects the lungs and can cause symptoms like a persistent cough, chest pain, and coughing up blood.

Meanwhile, extrapulmonary TB affects other parts of the body. This type of TB can cause symptoms such as back pain, headaches, and weakness or numbness in the limbs.

If you notice any of these symptoms, it’s important to see a doctor right away. Early detection and treatment can help prevent the spread of TB to others. In some cases, TB can be life-threatening if left untreated.

Stages of TB Infection

Tuberculosis (TB) infection in the lungs happens when TB germs survive and multiply. The infection develops through three distinct stages, each with different symptoms.

The initial phase is the primary infection of tuberculosis (TB). During this stage, the immune system attempts to fight the germs. Some people may not experience any symptoms, while others might have mild, flu-like symptoms including:

• Low-grade fever
• Feeling tired
• Mild cough

Following the initial infection, latent tuberculosis (TB) infection occurs. In this stage, the immune system creates a barrier around the infected lung tissue.

The germs remain alive but contained, causing no symptoms or damage as long as the immune system keeps them under control.

Active TB disease occurs when the immune system fails to contain the infection. This can happen shortly after the primary infection or after years of latent infection. Active TB in the lungs typically develops gradually with worsening symptoms such as:

• Persistent cough
• Coughing up blood or mucus
• Pain in the chest
• Discomfort when breathing or coughing
• Fever and chills
• Night sweats
• Weight loss
• Loss of appetite
• Extreme fatigue
• General feeling of illness

TB can spread beyond the lungs to other body parts, creating what doctors call extrapulmonary tuberculosis. Symptoms depend on the infected area but commonly include fever, chills, night sweats, weight loss, loss of appetite, fatigue, general illness, and localized pain.

Common sites for TB outside the lungs include:

• Kidneys
• Liver
• Spinal fluid (surrounds the brain and spinal cord)
• Heart muscles
• Genitals
• Lymph nodes
• Bones and joints
• Skin
• Blood vessel walls
• Larynx (symptoms similar to lung TB)

Children with TB show different symptoms depending on age:

• Teenagers: Similar symptoms to adults.
• Children (1–12 years old): Persistent fever and weight loss.
• Infants: Poor growth and weight gain.

Infants with TB affecting brain fluid may seem lethargic, irritable, frequently vomit, feed poorly, have a bulging soft spot on their head, or exhibit weak reflexes.