Syncope (SIN'ko-pe) is temporary dizziness, loss of consciousness and posture, described as "fainting" or "passing out." It's usually related to temporary insufficient blood flow to the brain.....

It most often occurs when the blood pressure is too low (hypotension) and the heart doesn't pump a normal supply of oxygen to the brain.

It may be caused by emotional stress, pain, pooling of blood in the legs due to sudden changes in body position, overheating, dehydration, heavy sweating or exhaustion...

Maybe your BP is too low.....drink something with caffeine and rehydrate yourself with water....you know how dry weed makes a person....if that does not help I would see a doctor....hope you feel better soon...