Skin Care Education

Hyperpigmentation

Areas of skin that appear darker than the surrounding complexion as a result of excess or uneven melanin production. An umbrella term covering several distinct types with different causes, behaviours, and degrees of persistence.

What Is Hyperpigmentation?

Hyperpigmentation is a broad term for any area of skin that appears darker than the surrounding complexion as a result of increased or concentrated production of melanin, the natural pigment produced by specialised skin cells called melanocytes. Melanin determines skin, hair, and eye colour, and plays an important protective role by absorbing ultraviolet radiation and shielding deeper skin cells from UV-related damage. When certain areas of skin produce more melanin than the surrounding tissue, a visible difference in colour results.

Hyperpigmentation is extremely common and affects people across all skin tones, though its visibility, persistence, and clinical significance vary considerably between skin types. Darker skin tones have a higher baseline density of melanocytes and tend to produce more pronounced and more persistent hyperpigmentation in response to the triggers that stimulate excess melanin production. Lighter skin tones may develop hyperpigmentation that is less deeply deposited and more responsive to management.

It is important to understand that hyperpigmentation is not a single condition but an umbrella term that covers several distinct types of pigmentation change with meaningfully different underlying causes, different patterns of distribution, different degrees of persistence, and different responses to management approaches. Identifying which type is present is the essential first step in understanding what is driving it and what is likely to be effective in addressing it.

Types of Hyperpigmentation

Solar lentigines (sun spots / age spots): flat, well-defined, consistently coloured darker patches caused by cumulative UV exposure. Most common on the face, hands, chest, and other chronically sun-exposed areas. Stable and tend not to fade without targeted management.
Post-inflammatory hyperpigmentation (PIH): flat dark marks that develop in the skin following an inflammatory event such as acne, eczema, a cut, burn, or any other cause of skin injury. Can affect all skin tones but tends to be more pronounced and longer-lasting in medium to deeper skin tones. Gradually fades over time, though the rate varies considerably.
Melasma: diffuse, symmetrically distributed patches typically appearing across the cheeks, forehead, upper lip, and chin. Driven primarily by hormonal activity. More persistent than other hyperpigmentation types and prone to recurrence even after effective treatment.
Freckles (ephelides): small, scattered concentrations of pigment that are largely genetic in origin. Most apparent in lighter skin tones. Darken with UV exposure and may fade with reduced sun exposure or with age.
Drug-induced hyperpigmentation: pigmentation changes caused by certain medications, including some antimalarials, chemotherapy agents, antipsychotics, and other drugs, which can stimulate melanin production or cause other pigmentary changes as a side effect.

Causes and Contributing Factors

Factor	Description
UV exposure	The most widespread and consistent external cause of hyperpigmentation. UV radiation stimulates melanocytes to produce melanin as a protective response. Repeated UV exposure over time leads to localised overactivity of melanocytes in sun-exposed areas, producing the concentrated patches characteristic of solar lentigines. Existing hyperpigmentation of all types is also darkened and maintained by ongoing UV exposure.
Hormonal changes	Fluctuations in oestrogen and progesterone are the primary drivers of melasma. The hormonal milieu of pregnancy, the use of oestrogen-containing contraceptives, and the hormonal shifts of perimenopause can all trigger the diffuse, bilateral pigmentation characteristic of melasma in susceptible individuals. Hormonal activity also increases the sensitivity of melanocytes to UV stimulation.
Skin inflammation	Any inflammatory event in the skin stimulates melanocytes in the affected area to produce excess melanin during the repair process, leaving a flat dark mark after the inflammation resolves. The intensity of the inflammatory stimulus, the individual’s melanocyte reactivity, and their skin tone all influence how significant the resulting post-inflammatory hyperpigmentation is.
Genetics	The density of melanocytes in the skin, their sensitivity to triggering stimuli, and the skin’s tendency to produce hyperpigmentation in response to UV and inflammatory triggers are all significantly influenced by genetics. Darker skin tones, which are associated with higher melanocyte density and activity, are inherently more prone to pronounced and persistent hyperpigmentation.
Certain medications	A range of medications can induce hyperpigmentation through various mechanisms, including direct stimulation of melanin production, photosensitisation that increases UV-driven pigmentation, or deposition of the drug itself in the skin. Individuals on photosensitising medications are at increased risk of UV-triggered pigmentation.
Heat exposure	Beyond UV radiation, infrared heat from the sun and other sources has been shown to independently stimulate melanin production and can trigger or worsen melasma in susceptible individuals, even in the absence of UV exposure. This is a relevant consideration for those with hormonally driven pigmentation who take care to avoid UV but remain exposed to significant heat.
Skin barrier disruption	Anything that repeatedly disrupts or inflames the skin barrier, including inappropriate skincare products, over-exfoliation, and certain professional treatments, can trigger post-inflammatory hyperpigmentation, particularly in medium to deeper skin tones where melanocyte reactivity is higher.

Frequently Asked Questions: Hyperpigmentation

Deeper skin tones have a higher inherent density of melanocytes and a greater capacity for melanin production. When a pigmentation trigger such as UV exposure, inflammation, or hormonal activity stimulates melanin production, the response in deeper skin tones tends to be more intense, producing more pigment, depositing it more deeply in the skin, and maintaining it for longer. The contrast between the hyperpigmented area and the surrounding skin is also often greater, making it more visually significant. Additionally, some treatment approaches that are effective for pigmentation in lighter skin tones carry a higher risk of triggering further post-inflammatory pigmentation in deeper skin tones if not carefully selected and calibrated.

No. Melasma is a specific subtype of hyperpigmentation with a primarily hormonal driver that distinguishes it from sun spots and post-inflammatory marks. It tends to appear in broader, more diffuse, symmetrically distributed patches rather than the discrete spots of sun damage. It is significantly more persistent than other forms of hyperpigmentation and more prone to recurrence after treatment, because the underlying hormonal activity that drives it continues regardless of surface management. These differences mean that approaches effective for sun spots or post-inflammatory marks may be insufficient or need to be combined with different strategies for melasma.

The pigment that has been deposited can be broken down and cleared by the body, and treated areas can become significantly lighter. However, if the underlying triggers remain active, including ongoing UV exposure, continuing hormonal activity, or recurring skin inflammation, new pigmentation will form over time. The tendency to develop hyperpigmentation in response to these triggers does not resolve with treatment. This is why sun protection is considered a non-negotiable component of managing hyperpigmentation of any type, and why melasma in particular requires ongoing maintenance rather than a single course of treatment.

Yes. Hyperpigmentation can develop across the full spectrum of skin tones. However, the type most commonly experienced, its visual prominence, its depth, and its persistence vary considerably between skin tones. In lighter skin tones, UV-related sun spots and freckles are particularly common. In medium to deeper skin tones, post-inflammatory hyperpigmentation and melasma tend to be more prominent concerns, occurring more readily, presenting more visibly, and persisting for longer. A thorough understanding of these differences is important in approaching hyperpigmentation appropriately across all skin tones.