What Causes Hyperpigmentation?

Skin Education · Hyperpigmentation Series

What Causes Hyperpigmentation?

Sun, inflammation, hormones — and a few things that might surprise you. Here is a full breakdown of what actually triggers hyperpigmentation and where it tends to show up.



Hyperpigmentation is caused by an overproduction of melanin in a localized area of skin, usually triggered by one of three things: sun exposure, inflammation, or hormonal changes. Each of these prompts melanocytes, the pigment-producing cells in your skin, to work overtime, leaving behind a spot or patch that's darker than the surrounding skin.

Knowing the "why" behind your hyperpigmentation is genuinely useful because the cause often points toward the most effective way to prevent new marks from forming while existing ones fade.

The Three Core Triggers

01 Sun & UV Exposure Most Common

Sunlight is the single most common driver of hyperpigmentation. UV rays stimulate melanocytes directly, which is your skin's natural (if imperfect) defense mechanism against further UV damage. A sunburn is an intense, short-term version of this response, but even everyday, low-level sun exposure adds up over time.

This cumulative effect is exactly how sun spots and age spots form, and it's also why hyperpigmentation almost always looks worse after a summer of unprotected exposure. Because this cause is so preventable, daily broad-spectrum sunscreen is consistently the top recommendation for anyone managing hyperpigmentation.

02 Inflammation (PIH) Very Common

Any time skin experiences inflammation — whether from a breakout, a cut, a bug bite, eczema, or an irritating skincare product — it can respond by producing extra melanin as it heals. This is called post-inflammatory hyperpigmentation, or PIH, and it's one of the most common reasons people develop dark marks, particularly from acne.

What Is Post-Inflammatory Hyperpigmentation?
03 Hormonal Changes Melasma

Shifts in hormones — including those tied to the menstrual cycle, birth control, or other hormonal changes — can trigger a specific, patchier form of hyperpigmentation called melasma. It commonly shows up across the cheeks, forehead, and upper lip. Hormonal pigmentation can be more stubborn than other types and often responds most reliably to a combination of strict sun protection and professional guidance.

If you have questions about hormonally driven pigmentation and your individual circumstances, including if you're pregnant or nursing, please consult your physician.


Can Sunburn Specifically Cause Hyperpigmentation?

Yes. A sunburn is a significant inflammatory event for the skin, and once it heals, it's common to see darker patches left behind, especially in already sun-exposed or acne-prone areas. This is part of why sunburn prevention (rather than just sunburn treatment) is such a central piece of hyperpigmentation care.


Does Shaving or Waxing Cause Hyperpigmentation?

It can. Both shaving and waxing create small amounts of trauma and inflammation in the skin, and repeated irritation in the same area — like the bikini line, underarms, or legs — can trigger post-inflammatory hyperpigmentation over time. A few habits can help reduce this risk:

  • Using a sharp, clean razor and shaving in the direction of hair growth
  • Avoiding dry shaving without a lubricating product
  • Letting skin fully calm down between waxing sessions
  • Applying a gentle, barrier-supportive balm afterward rather than a heavily fragranced product

Can Certain Skincare Ingredients or Treatments Cause Hyperpigmentation?

This one surprises people, but yes — in specific circumstances. It's important to note that this is almost always about misuse or over-exfoliation rather than an ingredient being inherently harmful:

Vitamin C Serums
Can occasionally contribute to irritation if a formula oxidizes or is introduced too aggressively. Well-formulated, stable vitamin C used consistently is more often protective than problematic.
Azelaic Acid
Generally very well tolerated, but introducing it too quickly or layering with other strong actives can cause irritation that leads to PIH in sensitive skin.
Dermaplaning & Physical Exfoliation
Can trigger PIH if skin isn't properly prepped or if pressure is too aggressive, particularly on skin that's already reactive.
HydraFacials
Generally gentle, but choosing the wrong intensity setting for sensitive skin can occasionally cause more irritation than intended.
The common thread: anything that over-irritates the skin barrier can indirectly cause hyperpigmentation, which is why a gentler, more gradual approach to actives tends to serve pigment-prone skin best.

Body-Area-Specific Causes of Hyperpigmentation

Hyperpigmentation often has a slightly different cause depending on where it shows up:

Around the mouth & upper lip

Frequently linked to hormonal changes (melasma) or repeated hair removal in the area.

Around the eyes

Often related to inflammation from rubbing, allergies, or genetics affecting thinner under-eye skin.

On the neck

Commonly tied to sun exposure or friction from clothing and jewelry.

On the cheeks

Frequently, a mix of sun exposure and, in some cases, melasma.

On the back

Often linked to body acne healing into PIH.

On the hands

Almost always cumulative sun exposure, showing up as classic age spots.

Underarms

Typically related to shaving, friction, or reactions to deodorant ingredients.

Inner thighs

Usually caused by friction, especially in warmer months or with tighter clothing.


What Is Post-Inflammatory Hyperpigmentation, Briefly?

Since inflammation is one of the three biggest causes of hyperpigmentation, it's worth understanding PIH specifically. It's the flat, discolored mark left behind once inflamed skin — most often from acne — heals. It's extremely common, generally not permanent, and treatable with consistency.

Read the full guide: What Is Post-Inflammatory Hyperpigmentation

Building a Routine Around Your Specific Cause

Once you have a sense of what's driving your hyperpigmentation, you can build a more targeted (and less frustrating) routine:

Sun Exposure

Daily SPF is non-negotiable, and pairing it with a gentle exfoliating toner like Danucera's D22 Tonic can support surface renewal.

Inflammation

Focus on calming the skin barrier with something like Cerabalm to reduce ongoing irritation that keeps re-triggering pigment from shaving, waxing, or breakouts.

Hormonal

Sun protection becomes even more important, and it's worth discussing your options with a dermatologist — hormonally driven pigmentation often benefits most from professional guidance.

Quick Summary

Hyperpigmentation is triggered by three core causes: sun and UV exposure (the most common and preventable), inflammation from acne, injury, or irritating skincare, and hormonal changes that cause melasma.

Other contributors include shaving, waxing, friction, and misuse of active ingredients. Where hyperpigmentation appears on the body often points to its likely cause. Identifying your trigger is the most useful first step toward treating and preventing new marks.

Frequently Asked Questions

Sun exposure. It's the most common trigger and the most preventable one, which is why sunscreen is the most consistently recommended step for pigment-prone skin.
Yes. Hormonal changes, friction, certain skincare habits, and general skin irritation can all contribute, though sun and inflammation remain the two biggest overall causes.
If an area is repeatedly exposed to the same trigger — like ongoing friction, sun exposure, or recurring breakouts — it will keep re-triggering the same pigment response. Addressing the root trigger is key to breaking that cycle.
Not necessarily, but a compromised or irritated barrier does make skin more reactive and more prone to producing new pigment — which is why barrier support matters.
Not entirely, since some causes (like hormones and genetics) aren't fully within your control, but consistent sun protection and a gentle approach to actives can meaningfully reduce how often new marks form.

"Knowing the caue is the first step toward treating it with intention — not guesswork."

Danucera  ·  Simplified Skincare