The most common cause of vaginitis is due to sexual activity because sexual intercourse can cause changes in the pH level of the vagina, leading to a reduction in local resistance and the proliferation of pathogens. This can result in various types of vaginitis, such as fungal vaginitis, trichomonal vaginitis, and bacterial vaginitis, all of which are related to sexual activity. Therefore, it is essential to maintain hygiene during sexual activities, have a fixed sexual partner, maintain good lifestyle habits, avoid overwork and staying up late, as a stronger immune system can also reduce the likelihood of contracting vaginitis.