When it multiplies in the nervous system, the virus can destroy nerve cells. These nerve cells cannot regenerate, and the affected muscles lose their function due to a lack of nervous enervation - a condition known as acute flaccid paralysis (AFP). But basically, it causes paralysis.
Ron is being proactive knowing high blood pressure runs in his family he studied what the causes and signs were so he knows to avoid certain foods and to exercise to keep his blood pressure under control.
