Age spots on the face and hands are caused by sun exposure, tanning beds, and natural aging. 

More Info: Age spots, also known as liver spots or solar lentigines, are flat patches of skin discoloration that although painless, can cause the skin to look weary and aged. Often oval, age spots can range in size from a tiny freckle to a centimeter across and are usually brown, black, or gray.

What Causes Age Spots?

That healthy glow sought after in youth may not have been as healthy as you think. According to a study conducted by the American Academy of Dermatology almost half of the teens surveyed, though aware of the risks of skin cancer, believe that people look healthier with a tan. The fact is a tan is anything but a healthy glow. Tanning is the body's natural reaction to cell damage.

In the process by which tanning occurs, ultra violet rays activate cells called melanocytes that produce the brown pigment melanin to defend against UV damage. Age spots begin to develop when melanin is produced in higher concentrations than normal.

Melanin causing age spots can be produced by:

• Sun Exposure: Because sun exposure is the primary culprit for the majority of sufferers, age spots more prominently appear on face, hands, shoulders, and arms-the most frequently exposed areas of the skin.
  
  
• Tanning Beds: Any method of tanning, including tanning beds and sunlamps, that produce skin darkening through the production of melanin can contribute to age spots.
  
  
• Natural Aging: Advancing age can also be a natural cause of increased melanin and the appearance of age spots.
  

Is Older Skin More Susceptible to Age Spots?

As you age, your skin becomes thinner and loses fat making it more susceptible to wrinkles, dryness, and damage. Unhealthy habits recklessly undertaken in youth like smoking and sun exposure begin to bare their unsightly side effects, as the skin grows older. These same habits practiced in advancing age have more immediate effects.
Though they can occur before, age spots generally occur in people over forty since the skin is ultimately more susceptible and the melanin clusters that produce the appearance of age spots typically develop over time.

Are Age Spots Dangerous?

Medically referred to as benign or vascular pigmented lesions, age spots are generally harmless. They do not lead to cancer in and of themselves. That does not mean that the appearance of age spots should be ignored. Lentigo maligna melanoma is a form of skin cancer that also occurs as a result of sun-damaged skin. At its most treatable stage, LMM can be mistaken for a harmless age spot, so it's best not to self-diagnose.