In most people who breathe in TB bacteria the body s immune system is able to fight the TB bacteria and stop them from multiplying. This is called TB infection. People who are infected with TB do not feel sick do not have any symptoms and cannot spread TB. If an infected person s immune system cannot stop the bacteria from multiplying the bacteria eventually cause symptoms of active TB which is called TB disease. Only 10 of all people with TB infection may suffer from the TB disease. People with conditions like HIV diabetes mellitus malnutrition and those on treatment with immunosuppressant drugs anti cancer corticosteroids etc are at a greater risk of developing TB disease once infected.