Post-blemish scarring, freckles that expanded into full-blown sunspots from excess exposure, age spots usually all fall under the umbrella of hyperpigmentation.
Hyperpigmentation may be localised, as in the case of post-inflammatory hyperpigmentation or melasma, or more diffuse in its presentation. Diffuse hyperpigmentation tends to be associated with metabolic causes, certain medications, malignancy, or autoimmune or infectious etiologies.(3)