Darkening of the skin is caused by an increase or release of the pigment melanin into the skin's cells after exposure to ultraviolet radiation. Melanin is produced by cells called melanocytes and protects the body from absorbing an excess of solar radiation, which can be harmful.
Sunburns are a symptom of skin damage and are associated with skin cancer. Overexposure to the sun has been linked to melanoma. Too much sun can also lead to eye problems if UV Protected sun-glasses aren't worn, along with damage to the immune system.
Concerns about skin damage due to UV exposure have resulted in the development of products which give the appearance of a suntan without exposure to the sun.
A study by Mandeep Kaur, M.D., and others, published in the July 2004 issue of the Journal of the American Academy of Dermatology, Part 1, suggests that indoor sun tanning may be addictive. Ultraviolet light stimulates the production of endorphins (through the production of Vitamin D), resulting in a natural sensation of well-being.
In 2002, Dr. William B. Grant published an article claiming that 23,800 premature deaths occur in the US annually from cancer due to insufficient UVB exposures (apparently via vitamin D deficiency).  This is much higher than 8,800 deaths occurred from melanoma or squamous cell carcinoma, so the overall effect of sun tanning might be beneficial. Another effect of vitamin D deficiency is osteomalacia, which can result in bone pain, difficulty in weight bearing and sometimes fractures.
Ultraviolet radiation has other medical applications, in the treatment of skin conditions such as psoriasis and vitiligo. Sunshine is informally used as a short term way to treat or hide acne, but research shows that in the long term, acne worsens with sunlight exposure and safer treatments now exists.
To avoid sunburn or excess tanning, covering up skin, wearing hats and staying out of direct sunlight is the primary defense.
If long sun exposure cannot be avoided or is desired one should use sunscreen, tanning oil or various over-the-counter creams. The SPF (Sun Protection Factor) number on a sunscreen product shows its rated effectiveness. Products with a higher SPF number are those designed to provide more defense for the skin against the effects of solar radiation. However in 1998, the Annual Meeting of the American Association for the Advancement of Science reported that some sunscreens advertising UVA and UVB protection do not provide adequate safety from UVA radiation and could give sun tanners a false sense of protection.
Tanning oils or creams, when applied, are usually thicker on some parts of skin than on others. This causes some parts of skin to get more UVA and UVB than others and thus get sunburns. For this reason, tanning oils or creams may increase the occurrence of skin cancer and other skin diseases.
Disclaimer: this website is for informational purposes only, and is not intended to be a substitute for a professional medical diagnosis, opinion or suggested course of treatment. Please see your health care professional for a professional medical opinion, and refer to our Disclaimer regarding your use of this website.