Tuberculosis (TB) is an infectious disease caused by the bacteria mycobacterium tuberculosis. The bacteria spreads through the air from person to person and mainly attacks the lungs, but it can affect other areas of the body.
The majority of people exposed to the bacteria don't experience tuberculosis symptoms right away. Instead, the infection may go through three stages.
Primary infection: This is when the bacteria first enter the body. In many people this causes no symptoms, but others may experience fever or respiratory symptoms. Most people with a healthy immune system will not develop any symptoms of infection, but in some people the bacteria may grow and develop into an active disease. Most primary tuberculosis infections are asymptomatic and followed by a latent infection.
Latent infection: The bacteria is in the body and can be found through tests, but is not active. During this stage you don't experience symptoms and can't spread the disease to others.
Active disease: The bacteria are active and multiplying. You'll feel sick and it will be contagious. It's important at this point to seek immediate treatment to avoid complications and infecting others.
The vast majority of people don't have a problem because the organism enters their body and is then handled by their immune system. Tuberculosis is more likely to enter the active phase in people who have acquired the infection recently (within two years). It's also more likely to be active among those whose immune systems are weakened as a result of malnutrition, old age, infection with HIV, immunosuppressant drugs, or among people who are on dialysis.
Many people with tuberculosis won't know they have it unless they get tested because there won't be any symptoms from latent infection. Once tuberculosis becomes active, symptoms may not show up in full force right away. The first thing you may notice is a bad cough that doesn't go away, or chest pain. Other symptoms of active tuberculosis may include a general sense of being unwell; coughing blood or phlegm; chest pain; shortness of breath; loss of weight and appetite; night sweats; intermittent fever; generalised body aches; fatigue.
Tuberculosis is spread through the air, so you can only get it by breathing contaminated air. If someone who is actively sick talks, coughs, sneezes, or speaks they can spread the disease. Risk factors for tuberculosis include poverty; HIV infection; homelessness; being in jail where close contact can spread infection; substance abuse; taking medication that weakens the immune system; kidney disease and diabetes; organ transplants; working in healthcare; exposure to air pollution; cancer; smoking tobacco; pregnancy; age, specifically babies, young children and elderly people.
Diagnosing tuberculosis can be a complex process. A person's history and the likelihood they were exposed to someone with active disease is vital. A series of screenings and
