Almost everyone will experience some form of hyperpigmentation at some point in life. What we see as a dark spot is actually a special skin pigment called melanin. Your skin makes melanin for protection. Unfortunately sometimes we end up with more in some spots than others, which is why we see uneven color in the skin.
Luckily you can learn more about what’s causing your specific type of dark spots, which will help you stop hyperpigmentation naturally.
What is hyperpigmentation - the causes of dark spots on your face and body
Hyperpigmentation is a buildup of excess pigment in tissue such as skin.
There are several different reasons skin may produce an excess of pigment, and many are deeply rooted in the health of your skin and body. We'll have to go beyond the surface to find the source.
The most common forms of hyperpigmentation
Freckles
We are all familiar with these little spots throughout the body, often face and arms. Freckles are often due to genetics. Freckles are not harmful and some people may enjoy the aesthetics of freckles.
Melasma
This form of hyperpigmentation occurs when hormones from pregnancy have caused a pattern of pigment to appear on a new mother’s body. The pattern that shows up on the face is commonly located on the forehead, cheeks, upper lip, and chin. This form can also be due to hormonal medications such as hormonal birth control.
Postinflammatory hyperpigmentation
After a physical injury has occurred, your body starts to develop an excess of pigmentation in the spot where skin damage took place. People with naturally deeper skin colors are very prone to this type of hyperpigmentation.
Sunspots and Liver Spots
Often recognized when larger groupings of excess pigment most often on face, arms, legs, hands, often caused by stress and excess sun exposure. These often show up with advanced age.
The dark spot we can see on skin is just the start of this complex process. Let’s take a look at how skin pigment is made.
Going below the surface: The layers of the epidermis and how they cause hyperpigmentation
So now that we know what hyperpigmentation is, let's dive into what is happening in our skin that is causing dark spots.
The epidermis is the upper layer of skin that you can touch, and it’s made up of thousands of skin cells that your body sheds and replaces each day. Around 500,000,000 cells shed on a daily average! This shedding process is how we can create even skin tone in the long run. The epidermis is your protective barrier to the elements and is where you see the color of your skin.
Just like most of an iceberg is under water, most of what is happening with skin is occurring under the surface. Your epidermis has 4 main layers of cells and each skin cell that you see grows and moves up through these layers as it matures.
We’ll go through the layers from outer to inner.
- On the outside the layer you can touch is the Stratum Corneum. These cells are flattened, hardened, and dead and form a protective layer for you.
- The next layers are the Stratum Lucidum and the Stratum Granulosum. Cells here are in the process of being flattened.
- The third layer in is the Prickle Cell layer, or Stratum Spinosum. Cells in this layer have a nucleus still and are still living. This is where pigmentation is happening and being spread to cells.
- And the fourth, bottom layer is the Basal Cell layer. This is where special cells called melanocytes sit. Your melanocytes are the source of the pigment melanin that you see as dark spots. We’ll talk about them in just a moment!
Fun fact *With a healthy epidermis you will have new skin on average every 30 days !
How melanin is made in your skin to cause dark spots
Now that we know the field that we have, let's learn who the main players are that are causing our skin to create these hyperpigmentations on our bodies.
Keratinocytes and melanocytes are the two cell types you need to know. Melanocytes make melanin and keratinocytes receive it.
Keratinocytes carry the melanin pigment
Keratinocytes are the living cells in the lower layers of your epidermis. They are often squared off in structure with a nucleus inside. They “talk” to each other about what is happening to your skin and how to respond. Information shared can vary from alerting your system that your skin is exposed to the sun, or letting your system know it has received an injury.
Visually the epidermis layer is like a brick wall with the bricks being keratinocytes and their more mature versions, corneocytes. These cells interpret and transfer the information received from the surface of skin to the melanocytes that dwell in the basal cell layer of the epidermis.
Melanocytes make the melanin pigment
Melanocytes are the actual source of melanin which is the pigment that you see in your skin, hair, and eyes. These are specialized cells, and in skin they never leave the basal cell layer. The Keratinocytes reproduce and migrate upward around them and the melanocyte stays put.
A melanocyte cell looks a bit like an upside down octopus!
About every 7 to 10 or so “bricks” apart in the basal cell layer there is a melanocyte. Imagine that the head of the octopus is resting in the basal cell layer and their happy tentacles are stretched out wide and weave up into the cell layer above them.
A melanocyte might have more than 8 tentacles and technically the tentacles are called dendrites. The dendrites can be longer or shorter in different people, which affects pigment placement.
Each melanocyte serves melanin pigment to about 30-40 keratinocytes.
Your octopus (your melanocyte) gets excited by messages from your other skin cells and exposure to UV light.
Try thinking of pigment formation as the octopus dancing and throwing glitter around. It’s a party octopus! Glitter is a great metaphor for pigment granules as well because when you get glitter on something it’s very hard to get it all off! The pigment granules that your octopus spreads get stuck to your keratinocytes and eventually become part of them.
Fun fact* Every human has roughly the same number of melanocytes.
Wait a minute … if everyone has the same amount of melanocytes why do we have such a rainbow of skin colors?
Melanin and skin color
The number of melanocytes is not the factor that causes the amounts of melanin production. Some people's melanocytes are more active than others, and the pigment granules (their party glitter) are made in a larger size. In deeper skin colors the octopus arms may also be longer to distribute pigment higher up in the layers of skin. These three major factors cause the skin to pigment more and faster.
There are also multiple types of pigment (party glitter).
Eumelanins are pigments of brown to black. Pheomelanin are yellow to red pigments
The unique combination of these two types of pigment in your skin makes everyone’s beautiful skin shade and tone unique!
Melanin in black skin
People with “black” skin tend to have the most eumelanin.
People with Northern European ancestry have more pheomelanin.
Causes of hyperpigmentation
The process of making and distributing skin pigment is called melanogenesis. Complex chemical messages control this process. The first chemical released in the process is tyrosine. That initial tyrosine then evolves through further reactions to produce eumelanins or pheomelanin.
Triggers for the melanogenesis process that creates dark spots include:
- Hormone changes such as high levels of estrogen in oral contraceptives and pregnancy can trigger uncontrolled pigment production
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Skin can “see” UVA light with a receptor that also appears in your eye, and this triggers melanin production within hours of exposure.
- Certain drugs can trigger more pigment production such as antimalarial drugs, chemotherapy, and NSAIDs (non steroidal anti-inflammatory drugs such as ibuprofen)
- Injury to skin can cause a release of pigment to prevent damage to living cells as the skin heals. This is post-inflammatory hyperpigmentation.
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Melanocytes are very prone to age-related damage, and can begin malfunctioning and releasing pigment unevenly, too much, or too little.
The skin benefits of having more melanin in your skin
Although you may not appreciate the dark spots in your skin, hyperpigmentation can be an indication that your skin is trying to do its job of protecting you. If the epidermis is sending down messages of distress the melanocytes are going to kick into gear and create more pigment for that area as a natural protector and extra barrier from the perceived danger.
Melanin is a natural sunscreen compound for your skin. The pigment absorbs UV light and helps protect the skin underneath from sun damage. It is estimated that melanin can absorb 50 - 75% of the sunlight that reaches your skin, so having more is a big benefit! Melanin also has antioxidant activity and is capable of scavenging for free radicals that can harm skin.
People with more eumelanin, like in black skin, have an even bigger advantage! Eumelanin has been found to be a superior sunscreen vs pheomelanin.
Pheomelanin is also more stressful for melanocytes to produce, and creates more free radicals as part of its production. This means that people with fair skin really need to be thoughtful about time spent in the sun. Even the natural melanin protection that your skin can make creates stress for the skin.
If you notice hyperpigmentation it could be a sign that your body is experiencing stress related to poor nutrition, excessive sun exposure, chemical imbalances in the body, or skin irritation. This is your opportunity to dig a little deeper and find the root cause of your hyperpigmentation so that you can support your body better.
Want to know why you have hyperpigmentation? Read our follow up article "Why do I have hyperpigmentation? 9 reasons dark spots show up on skin" to start figuring it out and take steps to support your skin.
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