I have a painful, sudden lump under the skin on my neck on the left side only. located just under my jaw about half way back to wisdom tooth.

See Dr. right away: Could be a number of things, an inflamed cyst, an abscess (bacterial infection), an inflamed lymph node and others. Need evaluation as soon as possible.

See your dentist: You should see your dentist to rule out a more severe cause such as oral cancer. He will be able to recommend treatment if necessary.

See your dentist: This is quite probably an infected tooth and needs to be diagnosed and treated properly. There is significant potential for the lump, or isolated infection , to spread and threaten your health severely. Call today.