The pain you're describing is typical of a disk herniation at the L3/L4 disk. This can be confirmed through an MRI or CT, but the symptoms are pretty identifiable: sharp, stabbing pain at the lower/mid back region, that follows down the side of the spine, across the waist and hip, across the left or right thigh, and stopping at the inside of the knee. If the pain goes down the back of the leg, then the disk involved is usually the L4/L5 or S1 disks.
The reason the pain travels down the leg is that the nerve is being compressed by the disk herniation, which is when the disk bursts through its protective membrane at weak spot. The pain travels down the nerve pathway, which is how you can tell which disk is being affected.
Many things can cause a disk herniation - it can be something as traumatic as an accident, or something as simple as bending over to pick up a pencil off of the floor. While the membrane will eventually heal, it will always be a weak spot and prone to being herniated again.
Any kind of pain like that lasting more than a week should be looked at by a doctor, preferably a neurosurgeon (stay away from orthopedists - they know jack about dealing with spinal nerves), to get an MRI or CT done to confirm the problem. If the herniation is bad enough, it will also cause muscle spasms, which feel like sharp, shooting pains in the area of herniation. The normal treatment is anti-inflammatories, muscle relaxants and bedrest - getting pressure off of the spine is the most important thing in getting it to heal. Do not sleep on your stomach, and if you do on your back make sure your legs are elevated enough to get pressure off the lower back. The best position is on your side in a fetal position, with a large pillow or cushion between your legs/knees to get pressure off of the hips/lower spine. It takes time to heal - in the days when I still had those disks I sometimes spent as long as a month or more on my back healing up.
Doing nothing is a bad idea, regardless of whatever responsibilities you may have. If you don't deal with it, the chances of real long term damage are probable, and if you think you're in pain now, then you'll learn a whole new range of definitions for pain.
I've added some links below to some good pain and spine sites - check them out and find yourself a good doctor to deal with it. The longer you let it go, the worse it will be and harder to treat later on. Don't let anyone talk you into surgery unless you're at the point where you're facing a wheelchair either.
In foil, the target area is from the neck, down to the groin, but it goes around to the back also.
Only if you close your mouth and swallow it goes back down
you are having a heart attack
No, not necessarily. However, if your whole physical server goes down, and it hosts both, then they will both go down.
You are having an orgasm.
It is the bone that goes down your back and to which your nerves are connected to.
subduction zone
Hydrogen & helium
Goes to jail for having chucks back in a bar fight after punching a man.
troposphere
The mantle
Subduction zone