Swelling and infection in the vaginal area can be caused by bacteria, fungi, irritation, poor hygiene, sexually transmitted infections, or changes in vaginal pH. Metronidazole is often prescribed for certain vaginal infections, especially those caused by bacteria. Many people start to feel better, with less discharge, swelling, odour, or discomfort, after beginning treatment. This medicine is usually safe when taken as your doctor recommends, but some people may have side effects like nausea, stomach upset, a metallic taste, or dizziness. Do not drink alcohol while taking this medicine, as it can cause unpleasant reactions. To help with healing, keep the area clean and dry, avoid scented products, and wear loose cotton underwear to reduce irritation. Having sex may sometimes make discomfort worse until the infection clears up. If your swelling gets worse, itching increases, you develop a fever, notice thick white discharge, feel pain when urinating, or your symptoms do not improve after finishing treatment, please see your doctor again. You may need a different treatment if the infection has not cleared.