Hello I woke up this morning and after standing for a minute began to feel dizzy about to black out, sweat and was pale as well as my heart began to beat fast. I sat down and felt better . I stood up 2 hours after and the same thing happen again. I m a 43 yr old latin male I m 6 ft 2 289 pounds . I was 395 4 years ago and was diabetic I lost 100 pounds and was taken off medication as it was taking my surgar levels to low. I have been ok till 3 months ago that I passed a kidney stone. I had blood work and my blood pressure was fine I dont know what is wrong.