Hyperpigmentation Guide
The Science of Dark Spots: How Hyperpigmentation Forms
Understand the biological pathway behind melanin production, melanocytes, and the difference between PIH, melasma, and sun spots.
TL;DR
Quick answer
Understand the biological pathway behind melanin production, melanocytes, and the difference between PIH, melasma, and sun spots.
Focus on the routine decision that creates the most friction first, then keep the rest of the lineup simple enough to judge whether the change is helping.
What triggers excess melanin?
Hyperpigmentation is caused by an overproduction of melanin, the pigment that gives skin its color. This is carried out by specialized cells called melanocytes located at the base of the epidermis.
Common triggers include UV radiation, hormonal fluctuations (estrogen), and inflammatory triggers such as acne or eczema.
PIH vs. Melasma vs. Sun Spots
Post-Inflammatory Hyperpigmentation (PIH) is a direct result of skin trauma or inflammation, leaving flat red or brown marks.
Melasma is heavily driven by hormonal shifts and heat, appearing in symmetrical patches on the face.
Sun spots or solar lentigines form due to cumulative UV exposure over years, leading to clustered pigment deposits.
Frequently asked questions
Are post-acne marks scars?
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No. Post-acne marks are temporary discoloration (hyperpigmentation or erythema). True scars involve a loss or overproduction of skin tissue (indentations or raised bumps).
Keep exploring
Sources and citations
- Visit
[1]AAD sunscreen guidance
American Academy of Dermatology — Accessed 2026-04-20
Supports: spf-broad-spectrum, reapply-guidance
- Visit
[2]NHS acne overview
NHS — Accessed 2026-04-20
Supports: acne-overview, acne-triggers
- Visit
[3]AAD retinoid basics
American Academy of Dermatology — Accessed 2026-04-20
Supports: retinoid-usage, anti-aging-basics
- Visit
[4]Cancer Council sunscreen guidance
Cancer Council Australia — Accessed 2026-04-20
Supports: australia-sun, uv-exposure