I have a pinched nerve in my lower back, between L4-L5.
I have been experiencing episodes of being lightheaded very often. I have also been experiencing episodes of my vision going black accompanied by dizziness, this occurs 2-4times a day and varies in severity. I do not fully loose consciousness. When vision goes between 70-100% black I become disoriented in the 5-20 seconds that the episode lasts.
-Standing up from a chair has the biggest range and is the most severe when it comes to loss of vision ranging between 50-100% of black before slowly returning. These episodes also last the longest. 10-20 seconds
-Standing up from the prone position. Vision ranges from 20-60% with this one.
-Sitting on the ground. Vision about 0-20%
-These episodes also occur during random parts of the day doing other things, i.e. walking, standing. Vision being about 0-30%
I also have a naturally low blood pressure, usually being between 80-90 / 50-60, I was told this was due to all my years as a runner. My resting BP does go up to around 110/80 sporadically. Cause is unknown about this change.

I want to know if these two issues, the pinched nerve and being lightheaded and nearly fainting are related.