Ethambutol is a first-line antituberculosis drug widely used in clinical practice. Its effects mainly include interfering with the synthesis of bacterial RNA (ribonucleic acid) and inhibiting its growth, etc. Adverse effects mainly include visual impairment and arthralgia. 1. Function: It mainly interferes with the synthesis of bacterial RNA (ribonucleic acid) by penetrating into the body of Mycobacterium, thus inhibiting bacterial reproduction, and it is only effective for Mycobacterium during the growth and reproduction period. In clinical practice, it is mainly used in the combined treatment of tuberculosis caused by Mycobacterium tuberculosis, in addition, it can also be used in the treatment of atypical mycobacterial infection and tuberculous meningitis. 2.Adverse reactions: (1) The higher incidence is: blurred vision, eye pain, red-green color blindness or vision loss, this vision change can be unilateral or bilateral. (2) Less frequent are: chills, arthralgias, acute gout and hyperuricemia. (3) Rarely occurring are: rash, fever, and numbness or pins and needles of the skin. The use of ethambutol medication needs to be under the guidance of an experienced doctor, and patients should never take the medication without authorization.