What is this weird bruise on my leg?

I've been having pain my foot on and off for the last month.

It hurts when I stand on it to walk and I feel dizzy if I get up too quickly.

My doctor said it was overuse of the nature of my job.

I was getting changed it some other pants and noticed a bruise on my leg.

I don't know how it got there, I haven't fallen over recently or banged into anything.

It's on my left leg about 10cm up from the ankle.

It's a brown colour size of a small coin. When I touch it, the bruise disappears and when I let go it comes back.

The bruised part of my leg now also hurts when I walk.

Is this normal?

Is this all from my work as I have a bad shoulder and back too.

I feel like an 80 year old, not a 40 year old.

What is this weird bruise on my leg?
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