Microbiologically confirmed Pulmonary TB is the only infectious form of the disease. It is transmitted from person to person via droplets from the airway and the lungs of people with active disease. Pulmonary TB infection spreads when a person with active disease sings, coughs, or sneezes, releasing airborne TB bacteria in the vicinity of susceptible individuals. However, it does not spread through handshakes, using public toilets, sharing food and utensils, and casual contact.

Symptoms of TB are usually specific to the site affected by the bacteria.
TB disease in the lungs (pulmonary TB) is the most common form of TB, and is indicated by the following symptoms:

•    Persistent cough for two weeks or more
•    Unexplained weight loss 
•    Fever for more than two weeks
•    Chills and night sweats
•    Coughing up sputum (phlegm from inside the lungs) or blood in cases where the disease has progressed

Symptoms of TB disease in other parts of the body may include the following:
•    Bone TB may cause destruction of bones and joints
•    TB meningitis may cause headache or confusion.
•    TB of the kidney may cause blood in the urine.
•    Lymph node TB – enlarged lymph notes
•    TB of the spine may cause back pain.
•    TB of the larynx may cause hoarseness.

Symptoms common to all forms of TB include: Fatigue, loss of appetite, weight loss, fever (particularly in the evenings) and night sweats. 

TB infection is not the same as TB disease. People with TB infection have the Mycobacterium Tuberculosis bacteria in their bodies, likely caused by breathing in droplets  from a person with TB,  but they are not sick because the bacteria are latent. These people do not have symptoms of TB disease and they cannot spread the bacteria to others. In most cases, people with healthy immune systems can contain the infection at that point and not become ill with TB disease. They are often prescribed treatment to prevent them from developing TB disease. Low immunity is regarded as one of the common reasons why TB infection breaks into TB disease. Chances of progression from infection to disease is 5 to 10 per cent. TB preventive treatment may be given to people who have a high risk of progression.

People with TB disease are sick from TB bacteria that are active. They usually have symptoms of TB disease. They are prescribed drugs that can treat TB disease.

Tuberculosis (TB) is an infectious disease caused by the Mycobacterium Tuberculosis bacteria. TB usually affects the lungs (Pulmonary TB/Lung TB), but it can also affect other parts of the body, such as the brain, the kidneys, the spine, etc. (extra-pulmonary TB). Pulmonary TB is the more common form of TB.