Back of knee pain

[Supernova190188]

After having a week off work and then getting back to it, on the first day back I always get pain behind both knees at night when lying in bed, it's a constant pain, lasts for hours, could it maybe be hamstring pain? At work I'm always pretty active, and wear steel toe capped boots so maybe this wouldn't help.
Last night however pain was only in the right leg and was pretty bad, kept me awake half the night, I'd say on a pain scale out of 10 it would definatly have been a 6.5-7. Without actually going and seeing a doctor would any of you know what the cause of this weird pain could be?

[stew-S160]

The normal thing with pain in a particular area is an issue somewhere else. Look to the feet, calves, hamstrings and glutes. Some massage and strengthening work can fix a whole load of lower and upper body issues.

[jackh707]

Quite a common presentation of Sciatic nerve pain. Go see your GP.

[silverthorn2151]

Don't discount a Bakers Cyst.

I have a ruptured one at the moment and hurts like a bastid! The goo in my knee is escaping up and down the nerves and muscles and golly! Spent some time on morphine and a bunch of other stuff and I am waiting for an operation to sort it out, or as my surgeon says 'give it a good old scrape out', gulp.