What is hyperpigmentation? Causes, types and why it happens

Hyperpigmentation is one of the most common skin concerns worldwide, affecting people of all skin types and ages. It occurs when patches of skin become darker than the surrounding area due to excess pigment production.

Although hyperpigmentation is usually harmless, it can be frustrating to manage and may take time to fade without the right skincare approach. Understanding how pigmentation develops in the skin can help explain why dark spots appear and why they sometimes persist.

How pigmentation forms in the skin

Skin colour is determined by melanin, a pigment produced by specialised cells called melanocytes. These cells sit in the basal layer of the epidermis and distribute pigment to surrounding skin cells.

Melanin plays an important protective role by helping absorb ultraviolet (UV) radiation from sunlight. However, when melanocytes become overactive, they can produce excess pigment that accumulates in certain areas of the skin.

This process typically occurs in several stages:

1. Melanocyte stimulation – triggers such as UV radiation or inflammation activate pigment-producing cells.
2. Tyrosinase activation – enzymes involved in melanin production become more active.
3. Melanin transfer – pigment is transferred to neighbouring skin cells, leading to visible dark patches.

Because several biological processes are involved, hyperpigmentation often requires a multi-step treatment approach.

To learn more about how pigmentation develops and how it can be treated, read our guide on how to treat hyperpigmentation effectively.

Common causes of hyperpigmentation

Several factors can trigger excess melanin production in the skin.

Sun exposure

Ultraviolet radiation is one of the most common triggers of hyperpigmentation. When UV rays penetrate the skin, melanocytes increase melanin production to protect against cellular damage.

Over time, repeated sun exposure can lead to uneven pigment distribution and visible dark spots.

Hormonal changes

Hormonal fluctuations can stimulate melanocyte activity. This is why pigmentation conditions such as melasma are often associated with pregnancy, oral contraceptives or hormone therapy.

Inflammation or skin injury

When the skin experiences trauma or inflammation, melanocytes may respond by producing excess pigment during the healing process.

This can occur after:

• Acne breakouts
• Cuts or burns
• Rashes or insect bites
• Certain cosmetic procedures

Medications and medical conditions

Certain medications and underlying health conditions can also influence pigment production, although this is less common.

Types of hyperpigmentation

Hyperpigmentation can appear in several different forms depending on the underlying trigger.

Melasma

Melasma is characterised by symmetrical patches of brown or grey-brown pigmentation, most commonly appearing on the cheeks, forehead, upper lip and chin.

It is strongly influenced by hormonal factors and sun exposure.

Post-inflammatory hyperpigmentation (PIH)

Post-inflammatory hyperpigmentation develops after the skin experiences injury or inflammation.

Dark marks may remain after acne breakouts, eczema flare-ups or minor skin trauma.

Sun spots

Sun spots - also called solar lentigines or age spots - develop after years of cumulative sun exposure. They typically appear on areas frequently exposed to sunlight such as the face, neck, chest and hands.

Who is most prone to hyperpigmentation?

Although hyperpigmentation can affect anyone, some people are more susceptible.

Medium to darker skin tones

Individuals with deeper skin tones often have more active melanocytes, making the skin more reactive to inflammation and sun exposure.

People with inflammatory skin conditions

Conditions such as acne, eczema and dermatitis can increase the likelihood of pigmentation developing after flare-ups.

Frequent sun exposure

Regular sun exposure without adequate protection can significantly increase the risk of pigmentation.

If you're interested in protecting your skin from these triggers, read our guide to repairing, protecting and preventing hyperpigmentation.

Can hyperpigmentation fade?

In some cases, mild pigmentation may fade naturally over time as the skin renews itself. However, this process can take several months or even years depending on the depth of pigment within the skin.

Targeted skincare ingredients, exfoliation and sun protection can help accelerate this process and improve the appearance of uneven skin tone.

You can explore some of the most effective treatment ingredients in our guide to the best ingredients for managing hyperpigmentation.