I have been suffering with what I thought was sciatica in my leg, affecting my knee. But I pain is just in my knee now, I have had it since Sunday's 5k.
Usually sciatic pain eases with gentle exercise, this pain isn't shifting. It really hurts going up and down stairs and is starting to get me down.
Could it be runners knee?
Oh that sounds horrible, poor you. I imagine there could be lots of possibilities why your knee is hurting. Have you tried the old RICE method? Hope you feel right soon. X
I had a bad knee after running downhill, It really hurt to come downstairs, but not too bad up, to begin with it hurt a lot walking on uneven surfaces but not flat and hurt after one step of running. I don't know what was wrong but ended up resting (not running) for 4 weeks ice every night and it gradually felt better ! I then gradually got back to running 
The moral I learnt is not to push a knee injury it got worse when I did 
! I am not sure what I did and not sure what you have done but definitely use RICE and take anti inflammatories if you can ! 
Good luck
I have had my own knee problems. The best suggestion that I have is to see a knee doc. He/she will be able to best tell you what is wrong and how to repair it.
