Some times it can last a very long time, or a short time. Having that problem can effect your eating, or even your voice. I have it, and it always sounds like I try to make my voice deeper. But I don't, it's all my throat.
The swollen gland could be because of several possible medical conditions. Some of these conditions include tonsillitis, strep throat or lymphoma. It would be best to visit a doctor for a proper diagnosis and treatment.