Fever after taking tuberculosis medicine may be caused by the natural course of the disease itself, bacterial resistance, drug reaction, immune response and so on. 1. The natural course of the disease: tuberculosis requires regular medication for two to three weeks before symptoms can be effectively controlled, so if the medication is taken for a relatively short period of time, it may cause the fever symptoms to persist. 2. Bacterial resistance: With the gradual rise of drug resistance of Mycobacterium tuberculosis, some patients may not be sensitive to regular medication, which leads to difficulty in controlling symptoms and persistent fever. 3. Drug reaction: drug fever may occur with some of the drugs used for tuberculosis, such as rifampicin. 4. Immune response: after taking tuberculosis drugs, a large number of tuberculosis mycobacteria die and break down in a short time, breaking down more toxins, triggering an immune response and immune fever. There are other reasons for fever after taking tuberculosis drugs, such as the combination of other bacterial, viral and other infections, it is recommended to consult a doctor in time to identify the cause, under the guidance of the doctor’s scientific treatment. The medication should be used under the guidance of a professional physician, and should not be used arbitrarily.