Swollen left gland under my jaw and throat discomfort and one if my gums in my mouth hurts. what can i have?

Glands repond well: Any type of inflammatory problem in the head or neck can cause swelling in the glands. From a cold virus to periodontal disease. Don't assume it is just one thing. If it lingers more than a few days have it checked by a doctor or your dentist.

Many possibilities: Abscessed tooth with spreading infection, infected gums, ulceration, a tooth problem and a coincidental throat infection, and oh so many other causes. Before this gets out of hand please call your dentist for an emergency appointment.