Tuberculosis most commonly occurs in the lungs called as pulmonary tuberculosis. When tuberculosis develops outside of the lungs, then extra pulmonary tuberculosis occurs.
General symptoms of tuberculosis includes: weight loss, fever, night sweats, chills, loss of appetite, and fatigue.
In about 90% of cases, after tuberculosis infection becomes active commonly involves the lungs. Symptoms include chest pain and a prolonged cough producing sputum. About 25% of people remain "asymptomatic" i.e. they may not have any symptoms. Sometimes, people may cough up blood in small amounts, and in rare cases, the infection may lead to pulmonary artery or Rasmussen's aneurysm, resulting in extensive bleeding. Tuberculosis may later become a chronic illness and cause massive scarring in the upper lobes of the lungs. The upper lung lobes are more commonly affected by tuberculosis than the lower lung lobes. If there is either no better air flow, or poor lymph drainage within the upper lungs, then forms Chronic obstructive pulmonary disease.
In 15–20% cases, the infection spreads outside the lungs, causing other kinds of TB. These are generally known as "extrapulmonary tuberculosis". Extrapulmonary TB occurs most commonly in young children and immunosuppressed persons. In this category, more than 50% of cases are co-infected with HIV. Extra pulmonary infection sites include the bones and joints (in Pott disease of the spine), pleura (in tuberculous pleurisy), the lymphatic system (in scrofula of the neck), the central nervous system (in tuberculous meningitis), the genitourinary system (in urogenital tuberculosis), and among others. A form of osteomyelitis, occurs when the bacteria spreads to the bones, it is also known as "osseous tuberculosis". "Disseminated tuberculosis", is potentially a more serious, widespread form of TB, also known as miliary tuberculosis. About 10% of extrapulmonary cases are reported by Miliary TB.