I will keep it short, I ended up with pain which meant that when not working I had to lie down with my feet up all the time. That went on for months, do not put up with it.
Inform your manager and get him to refer you to OH assist (name use to be ATOS). Get a GP appointment, and get referred to a specialist. Your GP practice my do a self referral to a podiatrists (similar to a Chiropodist). You will get a phone interview from OH assist, tell them what treatment you are getting or waiting to be diagnosed and symptoms and how its effecting your ability to work. They will give a recommendation for what type of work you should do. My condition has still not been diagnose, I have been taken off a walking duty, keep your manager informed, do not deviate from OH assist recommendation, if the manager tries to change it, contact OH assist. This next bit is only my view and not a backed with a legal knowledge, if the manager gives you work when he knows of you condition and is outside OH assist advice then he is putting your health and safety at risk. There was a small hiccup with my situation and the manager said he could not give me certain work to do because he would then not be following RM policies or something similar. Do not put up with pain, taking pain killers is only hiding the pain and future complications. The situation I find my self in, is I would like to find new work to match my ability due to my condition, but no employer is going to employ someone with a unknown condition. I can not pack in RM as I need an income. I am not ill enough to be of work thankfully, extremely thankfully but I can not do certain work.