Yellowing teeth are very common and usually harmless. For home care, you can use whitening toothpastes containing mild abrasives or low-dose hydrogen peroxide, or over-the-counter whitening strips and gels containing carbamide peroxide. For faster, more significant results, I highly recommend visiting your dentist. They can perform a professional dental cleaning to remove surface stains or offer safe, in-office bleaching treatments. Please consult a dentist before starting any whitening treatment, especially if you have sensitive teeth or gum disease, to ensure the treatment is safe and effective for you.