Pain behind my right leg that travels down the out side of my keg

You probably be better running up those steep hills.

Maybe you should try some non steroidal medication regularly for a week or so , just to see what the difference it made. But why not to book an appointment anyway?

The GP should be able to advise you .

I used to have pain on the back of my leg/ knee when I trained a lot. More pressure or discomfort .

It turned out I have baker cyst there.

My surgeon prefers not to touch it and leave it as it is- cos its only swells at the time .

I hope you figure it out soon.

All the best .

I've read that pain in the back of the knee can be associated with a strained or torn posterior cruciate ligament, (PCL). This is the ligament that stabilizes your knee by keeping your tibia from moving to far forward past your femur, like when you run down hill and you go flat footed to slow down, you put a lot if stress on your PCL. If you Google torn pcl, you can read the symptoms to see if you are experiencing any of them. Best wishes.

Simplest starting point is to stop running for 10 days, take an NSAID (ibuprofen), ice and elevate. If it's just a sprain or strain, that should take care of it. If it doesn't, time to see an orthopedic surgeon, not your family doc. They start with an x-ray to see if anything is glaringly structurally wrong. This is usually negative. The important thing is the exam. An ortho knows how to twist, turn, push and pull your leg. When you say "ouch", the doc will know what part of the knee is the problem.

The next step is usually an MRI which is frequently inconclusive in soft tissue injuries. If it sounds to the doc like something minor, he/she might use a cortisone injection and/or recommend a specific brace for that knee component until it heals. That will probably mean zero running until you are better. Then, very light exercise until you can work back up to full pace with no pain.

If the doc does find a real problem like a tear of some kind, then the severity of the injury will dictate PT or a surgical fix. That last option is the ultimate fix if your diagnosis demands it. I played hockey for 45 years and messed up each knee twice. On all four occasions, the MRI showed nothing so my ortho did an arthroscopy, twice each knee. In all cases, he found the problem once he got the camera inside (two meniscus tears, two ripped femoral condyle cartilages). They were all repaired and I was back on my feet within days.

If your problem is similar to mine, your running days will be over sooner rather than later. Removing cartilage will accelerate a bone-on-bone condition and possibly arthritis leading to much more pain long term. Waaaay down the road, it will be TKR time. I finally needed one at 68; then you are forbidden to run as it will destroy the replacement in a few years instead of the 25-year lifespan. Running puts a huge load on the knee; be prepared for a doc somewhere down the line telling you that you have to stop. I had to give up hockey after all those decades of loving it. Ended up with a replaced hip, knee and four spine ops including two fusions...4 1/2 pounds of metal. Sooner or later, the pressure we put on our body from serious sports dedication takes its toll.

But for now, start small with the 10 day anti-inflammation protocol. If that fixes it but then starts reoccurring, I'd see the ortho surgeon. Best docs for people like us, work out of a sports ortho group, one associated with local college and pro teams. Those are the really good ones with lots of experience in these injuries. Good luck.