I had toothache a month ago and went away now it's back but the one side of my throat is sore aswell? what is this?

Needs to be seen: Did you ever see a dentist for the original toothache? You will need to see a dentist who can determine both the cause of your toothache and whether or not the sore throat is related.

Abscessed Tooth: You might have had other options had you taken care of it the first time but now your choices will be to have the tooth extracted or possibly a root canal (if enough tooth remains inctact) you need to see your dentist immediately since this is an infections that can become life-threatening if not treated especially since it is in your throat. You need antibitotic right away.

See your Dentist: Your previous toothache is an infection. The symptoms may have subsided but the actual infection probably hasn't. The glands in your throat may be reacting to the infection and causing the sore throat. Best to contact your dentist to evaluate the dental infection. If your dentist doesn't find the cause call your md. Good luck.