A tooth becomes impacted when there is not enough room to accommodate the space in the dental arch and growth becomes impossible.  After surgery to remove an impacted tooth, mild discomfort and some swelling is expected. This is part of the process and should not alarm you. You may use cold compresses to alleviate the swelling. In addition, your doctor will prescribe pain medication, which should be taken as directed. Patients are also advised to favor the extraction area and modify their diet for a few days to allow for healing.