Signs and symptoms of tuberculosis infection

Tuberculosis (TB) is a disease caused by germs that are spread from person to person through the air. TB usually affects the lungs, but it can also affect other parts of the body, such as the brain, the kidneys, or the spine. The disease caused by any one of a group of bacteria collectively known as the Mycobacterium tuberculosis complex. These mycobacteria include:
•M. tuberculosis (including subspecies M. canetti)
•M. bovis
•M. bovis BCG 
•M. africanum
•M. caprae 
•M. microti 
•M. pinnipedi 

When these bacteria enter the lungs, they are usually walled off into harmless capsules (granulomas) in the lung, causing infection but not disease. These capsules may later wake up weeks, months or decades later causing active TB disease.

The general symptoms of TB disease include feelings of sickness or weakness, weight loss, fever, and night sweats. The symptoms of TB disease of the lungs also include coughing, chest pain, and the coughing up of blood. Symptoms of TB disease in other parts of the body depend on the area affected.

TB disease can also involve multiple sites at once (disseminated TB disease). Other sites of non-respiratory TB disease include:
• Peripheral lymph nodes (TB lymphadenitis)
• Central nervous system (e.g., TB meningitis, tuberculoma)
• Abdominal cavity and/or digestive system
• Genitourinary system
• Bones and/or joints

Symptoms are usually mild and tend to present over a period of weeks, months, or sometimes years. TB disease symptoms are often initially mistaken for a smoker’s cough, allergies, or chronic bronchitis from a lingering cold or flu infection.
Signs and symptoms of tuberculosis infection