What Causes Fluid Retention On The Toes?

what would be the diagnosis of fluid on top of thr large toe/sometimes it feels hard. I am63 yrs old 5'4"

and I weigh too much. iam a diabetic for 35 yrs

my diabetes under control.I have artheritis,also neurothapy of hands & feet.. and have had 3 stents in the past 3 years. i see my dr. month-just want to know what it could be