You should speak with your doctor
. Whitish changes on the back of your tongue or your tonsil can be caused by many things, but they are always something that needs to be examined by a trained health professional. An ear-nose-and throat surgeon
(aka, ENT or otolaryngologist-head and neck surgeon) will be the best person to examine your throat and tonsil fully, because they are used to dealing with this sort of question. He or she will also be able to suggest appropriate therapy going forward. Sometimes, it is necessary to take a look at the area with a mirror or even a camera to determine if there is something more serious in the area. Depending on what your surgeon thinks, sees, and hears, he or she may recommend observation, antibiotics, or even taking a piece of the white area to examine it under a microscope. This can often be done in the office with satisfactory results, but may require a trip to the operating room. Things that are more concerning include if you have a history of smoking, drinking, or a family history of head and neck complaints such as cancer. Please speak with your doctor soon.