The warm golden cast of the sun is very alluring. And many people can't resist spending hours beneath its glow.

But not all of the sun's rays are pleasing. Ultraviolet (UV) light, the invisible but intense rays of the sun, damages your skin. Some of those harmful effects — such as suntan or sunburn — are visible right away. But other skin changes, including liver spots or deep wrinkles, appear and worsen over time. With repeated sun exposure, the skin damage can even progress into cancerous tumors.

From the first clue that your skin has undergone a change to the development of cancer, here's how the sun damages your skin and what you can do about it.

The first signs of skin damage

You're likely familiar with two of the more common sun-induced changes to your skin: suntan and sunburn. But you may not know that the darkening and reddening of your skin are the first signs of skin damage.

Suntan
A suntan is the result of injury to the epidermis, the top layer of your skin. A tan develops when UV light accelerates the production of melanin. Melanin is the dark pigment in the epidermis that gives your skin its normal color. The extra melanin — produced to protect the deeper layers of your skin — creates the darker color of a "tan." A suntan is your body's way of blocking out the ultraviolet rays to prevent further injury to the skin, but the protection only goes so far.

Sunburn
Eventually, ultraviolet light causes the skin to burn, bringing pain, redness and swelling. Depending on the severity of the burn, the dead, damaged skin may peel away to make room for new skin cells. Though the symptoms of sunburn may fade after several days, the damage to your skin remains. Sun exposure that is intense enough to cause a burn can also damage the DNA of skin cells. This damage sometimes leads to skin cancer.

People with darker skin pigment are less likely to burn because of the protective action of the melanocytes, which produce melanin. However, even those with darker skin types can burn with repeated exposures to UV light. This intense exposure can produce negative effects in the skin, including dry, rough patches, wrinkling and other skin disorders. So even though people with darker skin can tan and tolerate longer periods of sun exposure without "burning," the sun can still cause skin damage.

Ultraviolet light can damage all layers of your skin: the epidermis, dermis and subcutaneous tissue (fat). To protect itself from damage, your skin increases the production of melanocytes, which produce the dark brown pigment, melanin. The extra melanin makes your skin look darker or suntanned.

Photoaging: Looking older than you are

Over the years, your skin naturally begins to show signs of aging. For example, you may notice more wrinkles and thinner, more fragile skin. Exposure to UV light can accelerate these changes and make you appear older than you are. Skin changes caused by the sun are called photoaging.

The results of photoaging include:

• Weakening of connective tissues, which reduces the skin's strength and elasticity
• Thinner, more translucent-looking skin
• Deep wrinkles
• Dry, rough skin
• Fine red veins on your cheeks, nose and ears
• Freckles, mostly on your face and shoulders
• Large brown lesions (macules) on your face, back of hands, arms, chest and upper back (solar lentigines, or liver spots)
• White macules on the lower legs and arms