Is Sudden Swelling And Numbness Of Left Hand A Cause For Concern?

Hi
I woke up this morning with my left hand swollen and really red. May hand and arm felt limp but it went away after about 15 minutes. Should I be alarmed? I didn't have any pain, just weakness in the arm which went away with the swelling. I am a newly diagnosed diabetic not on any meds trying to manage it with diet. I have hypothyroidism for which I take Levothyroxin. Other than that I am healthy 50 year old with no major illnesses.
What do you think?
Thanks