What does it mean when you have severe pain in your left knee and goes down to your foot and becomes numb?
Numbness usually means that a nerve is unhappy. Which nerve and where might be a good question for a neurologist who can examine the limb and associated nerves.
If the leg/knee is very swollen and the distal limb is going numb, that can represent a limb threatening emergency. Immediate attention may be required because the swelling can literally be cutting off the blood/nerve supply to the rest of the limb, a condition called compartment syndrome.
Seeing a doctor sooner rather than later might be the best course of action at this point.
Dr. Christina Lasich, MD