Sun spots (age spots), also known as lentigines, are harmless, flat, brown discolorations of the skin which usually occur on the back of the hands, neck and face of people older than 40 years of age. These spots more than anything else, give away a person’s age. Sunspots are caused by the skin being exposed to the sun over many years and are a sign of sun damage. If you do not believe that these brown marks on the back of your hands and face are caused by sunlight, look at the skin on your inner thigh.
You will see that the skin of the inner thigh is completely devoid of age spots. Sunspots are harmless and do not need to be treated unless they are changing or getting bigger than the surrounding sun spots.
The only way to prevent age spots is to use liberal amounts of sunscreen before the age of forty, avoid the sun, and wear protective clothing. These measures will also help prevent the formation of skin cancer and wrinkles.