How dangerous can be 90/50 blood pressure?

Caveman like...: 90/50 is the pressure we'd all have if we lived in a salt-free environment and got plenty of exercise. The only danger of this BP is when the body is chronically used to a much higher one, or the patient is elderly or with a compromised autonomic nervous system (as in with parkinsons) where standing rapidly can cause dizziness or, at worst, passing out.