Tuberculosis (T.B.) is a chronic debilitating illness caused by Mycobacterium tuberculoses. The most common form of illness affects the lungs as the germs enter the body through droplet infection. That is if a person suffering from T.B. talks or coughs or sneezes, the germs are expelled in the environment. They can enter through the nose of another person close to him. As one inhales the germs through the nose, they enter the lungs causing pulmonary T.B. But apart from the lungs other parts of the body can also be affected due to spread of the mycobacteria directly through adjoining structures or via the blood stream or lymphatics. The joints of the body are also not spared. But T.B. of the joints or tubercular arthritis commonly affects the large weight bearing joints like spine, hips and knees and usually one joint is affected. Pre existing arthritis like osteoarthritis or rheumatoid arthritis predisposes one to tubercular infection. Similarly pre existing trauma of the joints also makes them more vulnerable to T.B. HIV/AIDS patients are more vulnerable to all types of T.B., including that of joints. In case of children or adolescents, joints damaged by diseases like sickle cell disease makes them more vulnerable to acquire tubercular infection of the joints. Infection usually comes to the joints through lungs or kidney via the blood stream. Initially, there is synovitis, i.e. inflammation of the synovial membrane of the joint which provides lubrication to any joint. This manifests as swelling and pain over the joint. Later on there is involvement of the bones of the joint. As the disease persists and progresses there is destruction of the joint causing functional disability.Such a damaged joint is susceptible to be infected by bacterial infections like that by staphylococcus aureus. This further aggravates the pain and swelling and also poses a risk for developing sepsis which can be life threatening for the individual.The typical constitutional symptoms of T.B., i.e. evening rise of fever, night sweats, anorexia and weight loss may or may not be present with joint T.B. One may have associated pulmonary T.B. or joint involvement may be the sole manifestation of T.B. in a person.  Presence of constitutional symptoms, along with features of pulmonary T.B.  aid in the diagnosis of T.B. of joints in a person. If somebody has persistent joint swelling and pain in a large joint with or without deformity, which does not respond to antibiotics, T.B. of the joint should be strongly suspected. Diagnosis is confirmed by means of microscopic examination and culture of the synovial fluid for mycobacteria. Treatment is done by means of anti T.B. drugs. The treatment has to continue for minimum 6 months or even longer. In this regard it is important that the affected individual takes the treatment for the entire period as advised without interruption. Many times, as a person starts feeling good, he or she stops the treatment. Sometimes, the treatment is interrupted because one develops side effects of drugs.  Burning pain in feet, blurred vision, jaundice, e.t.c, are the common side effects of anti T.B. medicines. For whatever reason, treatment is interrupted, this leads to relapse and aggravation of the disease and also makes the germs resistant to the drugs, thus making cure difficult.Even after successful completion of the treatment at times sequel remain in the form of joint pains and deformity. This happens when the treatment was   started late   and   joint deformity had already started. The drugs clear the infection but joint deformity remains. Physiotherapy helps in relieving the joint stiffness and correcting early joint deformity. But in advanced cases, surgical correction is required. Balanced nutritious diet also helps in good recovery without side effects of drugs and sequel. People should be aware of the fact that joints can also be affected by T.B. In case of any suspected problem, they should seek medical advice before it is late.Dr. Rachna PandeSpecialist internal medicine-Ruhengeri Hospital