If tuberculosis is not actively and effectively controlled, mycobacterium tuberculosis can spread to all organs of the body through three routes: bloodstream, lymphatic tract, and direct dissemination, resulting in systemic tuberculosis, which is very serious at this time. For example, the spread to the pleura can result in a tuberculous pleural effusion, and some patients develop encapsulated pleural effusion or pleural hypertrophy or adhesions as a result. Tuberculosis spreads to bones such as the long bones of the limbs and the spine, and some patients develop fractures or paraplegia as a result. The spread to the liver, kidney, spleen and reproductive organs can affect the function of the corresponding organs. When the tuberculosis bacilli spread to the brain and meninges, tuberculous meningitis is formed. This type of tuberculosis has the worst prognosis and the worst treatment effect, and can often lead to disability.