Why Our Skins Darken When Exposed to The Sun?

Q: I never understood the reason behind it. Why our skin becomes darken when exposed to sun? Can anyone explain the scientific reason behind it? What should I do for my skin?
Expert Answer

The sun and the human skin have a very interesting relationship. Most of us grow up knowing that the sun is good for the bones and the body in general. Sometime in the shinning sun will give your body some much needed Vitamin D. Later on in life we learn that in reality, the sun is one of the worst enemies to your skin. You start to avoid it as much as possible and use protection. What happens is that as we grow older, the skin becomes less able to sustain continued sun exposure. Cells damaged by UV radiation are not automatically replaced.

Why do We Tan?

When Exposed to The Sun

An interesting phenomenon occurs when one goes out into the sun. After a short while, the skin becomes darker and richer in color. This is called tanning and it is a biological process that is triggered by the sun. The sun gives of ultraviolet rays. When you are outside, these rays hit your skin and damage some skin cells. This damage triggers the body to increase* the production of melanin. Melanin is the body pigmentation that protects against damage by these rays. When the concentration of melanin in the skin increases* the color and tone of the skin darkens. The more you stay in the sun, the darker the skin will get. This will go on up to a certain point where the damage to your skin gets worse and you may suffer from sunburns or sun spots.

What Causes Uneven Pigmentation?

Uneven skin pigmentation is an occurrence where melanin in the skin is not distributed uniformly. This results in some parts of the skin being darker than others. Causes of uneven pigmentation include:

  • Prolonged Sun Exposure: When certain parts of the skin are exposed to the sun they get darker than the other areas
  • Injury: The area around an injury tends to get darker than other areas
  • Medication Mostly Creams: Certain creams can also trigger an uneven distribution of melanin. Cosmetic medications in particular are major causes of this
  • Emotional stress


The best way to avoid uneven pigmentation is to avoid exposure to the sun for prolonged periods of time. If you need to be outside for extended time, wear protective clothing such as a hat or use sunscreen. Leading a healthy lifestyle can also help to avoid skin pigmentation. Additionally, use medications and cosmetic creams that have been approved and recommended by your doctor.

What is the Cure*?

You can easily cure* uneven skin pigmentation through a number of ways. You may decide to use homemade products such as lemon juice, papaya and milk or you may go for commercial treatments. Commercial treatments include skin lightening or whitening creams. Skin lighteners are more effective in treating uneven pigmentation although you have to deal with a number of side effects. Be very careful as you choose a skin lightener; avoid one with ingredients such as mercury and steroids.

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Contributor : Aneeca Younas (Consumer Health Digest)

Aneeca Younas is a versatile freelance writer with years of experience in writing content for health and beauty magazines and websites. With a background in journalism, she loves writing blogs and product reviews that provide valuable information to readers. As a passionate gamer, she also enjoys playing games and writing about them.

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