I'm reluctant to visit my GP as she has in the past admitted to knowing little about feet! A few days ago I suddenly found it very painful when I walk on the outer side edge of my right heel. First thing in the morning after a nights sleep it barely hurts but as I walk and the day goes on it becomes more and more painful until by evening I cannot bear to put any weight on that heel.
I find all down that outer side of my foot aches as does up intothe back of my calf.
I have in the past had two episodes of plantar fascitis in my left foot but this is nothing like that as with the p f it was agony when first walking especially after anight sleep and the pain was under my foot where the foot joins the heel so assume this problem is not p f.
The pain started about a week after changing the shoes I was wearing to an old pair with a lumpy sole- I have ditched these old shoes but the pain is not imroving at all.
I would welcome any possible explanation of what might be wrong before I visit my GP if possible.
Could be peroneal tendon. I had mine operated on in January and it is still healing. I have pain very similar to what you describe. My PT suggested I wear the night splint I had from PF at night. I thought he was touched in the head but 3 weeks later it is finally improving. He explained the foot naturally flexes down when sleeping and that strains the tendon. So I wear it every night now.
Good luck, the pain at the end of the day is so demoralizing.