Tuberculosis with cavity treatment for one month, spit a little blood may be because the tuberculosis has not been effectively controlled. It may also be caused by ruptured blood vessels in the trachea dilatation damage. 1. The disease itself: the reproductive viability of tuberculosis bacteria is very strong, is relatively difficult to be killed by drugs, so most of the tuberculosis need to take about six months. So the treatment of one month course is obviously too short, the drug has not yet played a role, the tuberculosis bacteria are still active, the formation of cavities accompanied by the discharge of necrotic lung tissue, so spit will have blood. 2. Tracheal dilatation blood vessel rupture damage: some patients may cough violently for many days, tracheal dilatation blood vessel rupture damage, so sputum with blood, you can review the lung CT or blood routine clear. Tuberculosis usually need to increase nutrition to avoid fatigue, maintain the quality of sleep, it is recommended that patients with symptoms in a timely manner, in accordance with the views of the doctor reasonable treatment, to avoid unauthorized use of medication to cause adverse effects.