How much do you know about your body's biggest organ—your skin? Did you know, for instance, that it's made up of three layers of different types of cells, each with its own specific job? Did you know that 95 percent of our outer skin cells (epidermis) are hard at work making new skin cells? What else would you like to know? We've got answers to five common skin questions right here.

Q: Why are some people light-skinned and some dark-skinned?

: Everyone's skin is made up of the same three layers—epidermis on the outside, dermis in the middle and subcutaneous underneath. One of the cells present in the outer layers of skin is called melanin. The more melanin you have, the darker your skin is. What about freckles? They're just spots where melanin cells are concentrated.

Q: What causes wrinkles?

: Most people think it's just an age thing, and while aging is definitely a factor, there are other things that contribute to wrinkles, including:

  • Sun exposure
  • Smoking
  • Poor nutrition
  • Repeatedly making the same facial expressions

As we age, the epidermal layer of skin becomes thinner and less able to provide skin flexibility. This is accelerated by poor lifestyle choices. What's more, less collagen is produced in the dermal layer so oil glands produce less oil making the skin dryer, less resilient and more prone to creasing.

Q: What causes acne?

It's not caused by chocolate, dirt, food oil, sugar or bacteria. It's caused by plugged oil glands in the skin. These oil glands produce a substance called sebum. If a pore gets plugged with sebum, it can become inflamed, which results in a pimple.

Q: What causes stretch marks?

Stretch marks are common during pregnancy, teenage growth spurts or times of rapid weight gain. They're the result of collagen and elastin breakdown when skin is stretched tight. In their early stages, they usually appear as red or purple wavy stripes but over time, they fade to a pale white or pearly/silvery color.

Some swear that rubbing their skin with heavy moisturizers during pregnancy will help skin stretch without creating marks, but others say it all comes down to genetics. Either way, dermatologists say the appearance of stretch marks can be diminished by using retinoid products and laser treatments.

Q: How can you keep my skin healthy?

Your skin needs proper nutrition and hydration to generate new cells, which are the key to having healthy, younger-looking skin.

That means...

  • Eat lots of fresh fruits and veggies, whole grains, lean proteins, and
    calcium-rich foods.
  • Drink lots of water.
  • Quit smoking. Cigarettes, and other tobacco products, speed up the aging process.
  • Wash your face with plain soap and water or a mild facial cleanser once or twice a day, but avoid antibacterial products and harsh cleansers, which
    may irritate skin and make breakouts worse.
  • Exfoliate with a washcloth or gentle exfoliating product several times per week and moisturize with an age-appropriate moisturizer formulated for your skin type.
  • Wear sunscreen every day and protect yourself from harsh rays by wearing long sleeves, pants, and a hat when you're going to be spending time in the sun.
  • See a dermatologist for regular skin checkups and whenever moles, bumps and skin changes develop.

Liesa Harte, MD, reviewed this article.


American Academy of Dermatology

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