Depending on what medication you are on, it can be a side effect of it, an angioedema or strong allergic reaction ... Go to Emergency!!!
Jesus
Totally agree with Jrbon, but would just like to add it could be associated with the thyroid gland in the neck, or medication for Hyperthyroidism.
THANK YOU FOR YOUR RESPONSE. yOUR ADVICE CONFIRMS MY THINKING THAT I SHOULD SEEK MEDICAL ATTENTION.
VON766