Hyperpigmentation is the term for areas of skin that become darker than the surrounding skin because of excess melanin. Common forms include age spots (sun-related), melasma (larger patches, often linked to hormones or pregnancy), and post-inflammatory marks left after acne or irritation.
Sun exposure drives and worsens most hyperpigmentation, so daily SPF is the foundation of both prevention and treatment, alongside ingredients such as vitamin C, retinoids and others. Any new, changing, or irregular dark spot should be checked by a clinician to rule out skin cancer. See age spots and hyperpigmentation.