Tuberculosis (TB) is an infection caused by a bacteria, It is easily spread from one person to another. TB may be in an active or inactive forms. Inactive forms can stay in your body and not make you sick. At some point the bacteria may become active which makes you sick. You can only pass the infection to other people if you have the active version.

TB can affect many organ systems but most often affects the lungs.

TB is caused by a bacteria. When a person with active TB of the lungs coughs or sneezes it releases the bacteria into the air. Nearby people may then inhale the bacteria. Brief or casual contact with someone who has TB will usually not lead to infection.

Your immune system may also be able to stop the bacteria from growing. This will lead to an inactive (or latent) form of TB. This inactive form may become active if you are ill or have a weakened immune systems. If you are ill or have a weakened immune system when you are exposed to TB you may quickly develop an active TB.

Pathway to the Lungs
Air pathway breathing
Mycobacterium tuberculosis is inhaled through the mouth and nose and travels down into the lungs causing TB.
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