The sciatic nerve is the largest and widest single nerve in the human body, running from the lower back through the buttock and down the lower limb. Sciatica is an irritation of the sciatic nerve. It’s usually associated with a muscle in the body below the glute muscle, which is called the piriformis. If that goes into any type of spasm, it creates a burning pain sensation. It compresses the nerve. And that’s usually associated, once again, with improper sitting or sitting for too long. People with severe sciatica can’t bring their body into any seated position, they have to maintain their leg straight, so they can reduce the irritation. If sciatica is not taken care of professionally, you will damage the nerve. And if sciatica is not tended to, it can eventually lead to some type of surgery.