Many of us have been happily tanning for years but have never stopped to wonder what a sun tan even is. We figure it is just our skin reacting to the sun in a certain way to protect us from a sunburn, or we think it is our skin darkening from being burned by the sun. There’s partial truth in these conceptions, but really, there is more going on with our skin that is interesting to know.
Let’s start with the sun (or even a tanning bed lamp). The sun (or lamp) emits UV rays that affect our skin in different ways. These UV rays consist of UVA rays and UVB rays. The UVA rays penetrate into deeper layers of our skin, while the UVB rays reach our outer layers of skin. Each type of UV ray interacts with our skin differently in this respect.
UVA rays penetrate to a deeper layer of skin where they stimulate cells called melanocytes, which produce melanin, which spreads throughout the skin. Melanin production is a reaction to cell damage caused by UV contact on the skin, and is the skin’s defense against UV damage. UVB rays will then oxidize this melanin, which gives the skin that brown color which is indicative of a tan. Melanin will absorb UV rays and protect skin cells from sun damage.
Basically, when you tan, your skin is establishing a defense against UV damage.
Sunburns, on the other hand, occur when your skin is heavily damaged by UV rays. The red appearance of a sunburn is due to increased blood flow to your skin, which is your body’s way of repairing damaged skin cells.
This is why we want to avoid sunburns as much as possible. Sunburns are not only painful, they are an indication that your skin cells have undergone a considerable degree of UV damage.
Carefully and responsibly cultivating a tan is a great way to build your body’s natural defenses against excessive UV exposure and skin damage.