Today exp lightheaded when exercising& noticed bluish fingertips afterwards. 3wks ago i fainted (dizzy, ringing ears, blurry vision) could be related?

A drop in blood flow: Something is causing, a compromised supply of blood to your extremities in your brain, when you exert yourself. At your age, a significant heart problem like blocked arteries or unlikely, but you may have a leaky heart valve. I would get yourself to a doctor, you delete an echocardiogram.

Yes: This could be a problem with your heart or circulation. Bluish fingertips are concerning, and I would see your doctor as soon as possible. These symptoms could definitely all be related and t is imperative that you make sure it isn't a sign of something serious.