Red glans and painful urination after using benzalkonium chloride may be due to the high concentration of benzalkonium chloride stimulation, in addition, it may also be a manifestation of allergy. 1. Benzalkonium chloride stimulation: benzalkonium chloride can be used to deal with inflammatory lesions such as glans or rashes, but it is irritating to the skin and mucous membranes, and if it is used in too high a concentration for glans disinfection, it will stimulate the glans and urethral orifice, which will lead to glans redness, pain when urinating and other symptoms. Because the localized skin of the glans is relatively tender, the skin will react when it is stimulated by the more concentrated drug. At this time, you need to use sterile saline, or cool boiled water for thorough cleaning, and keep dry and hygienic. 2. Allergy: In addition, it may also be caused by the patient’s allergy to benzalkonium chloride stimulation, after being stimulated by benzalkonium chloride, the glans will appear red, pain when urinating. If there is a red glans and pain when urinating after using benzalkonium chloride, it is recommended to consult a doctor in time and follow the doctor’s instructions for examination and treatment.