Anyone know what this is or may cause it?

[LemonJellyKelly]

Today I noticed these on both my arms just above the wrists, has happened before on one arm but the mark's just went away quickly.... anyone got any idea what might cause this?
No cuts or abrasions, cannot feel anything if rubbed with a finger.....

My Nan had diabetes and had spots similar to that on her arms and legs. Have you had a well check recently?

Ah ok thanks, will get checked out, last time I was given the all clear on that but that was a couple years ago...