All single or double handle sink faucets can be rebuilt with new stems and washers or cartridges to stop the leaking. If it is a two handle faucet, you should get parts for both sides even if only the hot or cold is leaking. Both stems are the same age and the other may leak shortly after you rebuild one. If your tub spout is leaking, your shower valve will need to be rebuilt also. The washers, o-rings, or cartridges can wear out over time and should be replaced.