Extremely painful

My left kidney has been hurting constantly for about 3 weeks. It's the sort of pain you get when you have a stitch. Any idea what it is?

Definetely not a stitch.
something more than it.
you need to go doctors/hospital. it seems weird that your kidney has been hurting for 3 weeks.

Could be drinking to much / to little... Either way go and see someone about it... A doctor, not a friend...

Well, if it isn't stitch, then it could be something serious, i would consider going to your doctor to get it checked out to be on the safe side.

its most likely serious.

I'd say it's a wee wee infection... I've had a good few myself.

how the hell do you realise that your kidney is the source of pain?

It hurts where your kidneys are :rolleyes:

I would just go to your doctor, if it's been 3 weeks.

as others have said, go get it checked out.