Is there a risk of permanent nerve damage from a herniated disc? and what would cause blood pooled at the base of a spine?

Disc: There can be permanent damage from a prolonged untreated herniated intervertebral disc. Weakness of leg muscles is the first sign that serious damage could be forthcoming and is an indication to have corrective surgery soon. Blood pooling causes are varied and include trauma, abnormal blood vessels prone to rupture, inflammation among other causes.

Yes there is a risk: There is a risk that if you have neurologic symptoms of pain/numbness/tingling/weakness in the leg(s) that the damage can be permanent. By far the most concerning is weakness and permanency could lead to long-term functional issues. All that said many people with herniated discs have mild or no symptoms and require little more than medication and physical therapy until symptoms improve.