People with TB disease are sick from the large number of TB germs that are active in their body. They usually have one or more of the symptoms of TB disease. These people may pass TB germs to others. The TB disease can cause permanent body damage and death. Medicines which can cure TB disease are given to these people.
People with TB infection also have the germs that cause TB in their body. But they are not sick because there are not as many of the germs, and the germs lie dormant (sleeping) in their body. They cannot spread the germs to others. However, these people could develop TB disease in the future, especially if they are in one of the high-risk groups listed under "Who gets TB disease?" People with TB infection can take medicine to prevent them from developing TB disease.