Definition: Hyperpigmentation is a common, usually harmless condition in which patches of skin become darker in color than the normal surrounding skin. This darkening occurs when an excess of melanin, the brown pigment that produces normal skin color, forms deposits in the skin. Hyperpigmentation can affect the skin color of people of any race. 
Age or Sun Spots
Age or "liver spots" are a common form of hyperpigmentation. They occur due to sun damage, and are referred to by doctors as solar lentigines. These small, darkened patches are usually found on the hands and face or other areas frequently exposed to the sun. Melanin pigment in the skin absorbs sunlight and helps naturally protect our skin from UV rays. However, as we age our skin's natural ability to fend off UV rays from the sun begins to deteriorate, and as a result, we see the development of age spots. 
Hyperpigmentation may be caused by sun damage (the most common cause), inflammation, or other skin injuries, including those related to acne vulgaris.
Many forms of hyperpigmentation are caused by an excess production of melanin. Hyperpigmentation can be diffuse or focal, affecting such areas as the face and the back of the hands. Melanin is produced by melanocytes at the lower layer of the epidermis. Melanin is a class of pigment responsible for producing color in the body in places such as the eyes, skin, and hair. As the body ages, melanocyte distribution becomes less diffuse and its regulation less controlled by the body. UV light stimulates melanocyte activity, and where concentrations of the cells are denser than surrounding areas, hyperpigmentation is affected. 
Laser Treatment - Laser treatment is generally very effective at removing age, liver, sun or brown spots on the skin. It is the treatment of choice for these spots, in fact. The treatment may require two or more sessions to completely remove the spots depending on how many there are and on which area of the body. In general laser removal of age spots is permanent, however people do sometimes see new spots appear as they go back out into the sun. These are new spots forming as a result of sun exposure, not a recurrence of the old, removed spots. Good sun-avoidance is key if you wish to see your skin free of sunspots.
Pain is Minimal with this laser treatment. And the session may last approximately 20 minutes, depending on the area to be treated. The cost for age spot removal with a laser can be affected by your location, your case, the area of the body in question, size of treatment area, and other factors. A single treatment on a small area may cost less than $100. Schedule a consultation with a laser surgeon for accurate cost information. 
Chemical Peel - Chemical peels involve the application of a chemical solution to the surface of the skin. The depth of the peel depends on the type of chemical and the method of application. The solution dissolves the damaged, age-spotted surface tissue. The damaged skin is then replaced with a more youthful looking layer. Prior to the application of the chemical peel, the skin is cleansed of surface oils. The chemical agent is then applied. You may feel an itching or tingling sensation during the treatment. This feeling will decrease when the chemical is neutralized.
There is usually little downtime from a chemical peel, though you may experience some redness or irritation immediately following the treatment. 
Microdermabrasion - Microdermabrasion refers to a category of techniques and devices that rejuvenate the very upper layers of the skin. It typically impacts the stratum corneum, helping to exfoliate the skin and removing dead cells. This results in an improvement in the texture of the skin, diminishing fine lines and improving areas of darker pigmentation such as age spots.
There are a variety of treatments categorized as microdermabrasion, such as creams with abrasive particulates that are scrubbed on the skin and procedures utilizing crystals that are passed across the skin with a suction device to sand the skin down. There are also non-particulate devices, using abrasive paddles or diamond coated paddles that superficially remove the top layer of the skin. 
Bleaching Creams - Bleaching creams are good for bleaching large areas of discoloration such as melasma. But when you’re trying to treat individual age spots, bleaching creams tend to bleach the area around the spots more than the spots themselves. Thus the topical bleaching creams are usually not good for bleaching individual brown spots because it is impossible to confine the cream to the area where the spot is.
Typical bleaching creams like hydroquinone and kojic acid don’t work as well as one would like. Topical Retin-A, on the other hand, can be good but it can also be irritating, especially to patients with light skin. In addition, you should never use bleaching creams or products like Retin-A or alpha hydroxy acids (which can also lighten the skin), without first using a sunscreen in the morning because all bleaching creams, Retin-As, and alpha hydroxy acids make you more sensitive to the sun. 
How to Choose A Doctor
When considering age spot, brown spot, liver spot or sun spot removal, the first thing to consider is ‘is my doctor a dermatologist?’ Spots on the skin can be cancerous or pre-cancerous and need to be reviewed by a skilled dermatologist who understands the treatment of skin cancer.
A second question is ‘Are you going to look at my spots and not laser over any pre-cancerous spots?’ Cancerous spots need to be handled appropriately before any treatment for aging skin or age spots. 
Several other questions I would ask are:
Wear Sunscreen, EVERYDAY.
Sunscreen is key. It doesn’t make any sense to treat brown spots if you aren’t going to protect your skin from the sun, which is the cause of the spots in the first place. So you need a high SPF sunscreen everyday, rain or shine.