Above: Sunspots tend to crop up on areas of your skin that have had a lot of sun exposure over the years
Sunspots are little areas of hyperpigmentation, that are part of the ‘natural’ ageing process and are generally harmless (although they can be unsightly). They’re caused by years of sun exposure, which triggers pigment-producing cells called melanocytes in your skin to produce more pigment in a small concentrated area.
This excess pigment is triggered in response to injury (sun damage), sort of the way scar tissue forms after a cut or puncture wound. Unlike moles that tend to ‘stick out’ above the skin, sunspots aren’t raised at all - run your finger over a sunspot, and it will feel just as smooth as the skin around it.
Just because sunspots are considered harmless doesn’t mean they should be ignored however. The problem with sunspots (and with moles, for that matter) is that skin cancer in its earlier stages can look very much like a flat, brownish spot (see below). Which means that if you ignore an area of hyper pigmentation on your skin, you could be delaying treatment for what may turn out to be melanoma.