I have had a freckle on my thigh for a long time now I noticed it is slightly raised. Should I be really concerned?
Not unless it has more than one color, or if it has really ragged edges. A raised freckle is just a mole, and little brown moles are harmless.
You should be concerned since a raise in a freckle can mean that it's growing bigger. The growth or raise can be caused by some negative factors. Visit a doctor as soon as possible for check up.