The afternoon fever in TB patients indicates that TB disease is active, which is a defense reaction of the body. On the one hand, the growth and reproduction of tuberculosis bacilli are vigorous, releasing large amounts of toxins. On the other hand, in the progressive stage of the disease, the lung tissue is constantly destroyed, the destroyed lung tissue and its metabolites are absorbed by the body to appear fever, after a day of physical activity, the absorbed substances are more and more body performance afternoon fever, severe patients have irregular high fever or even retention fever D consumption fever.