Blotchy brown spots develop on the skin for several reasons. Sun exposure over-time, certain medications (such as estrogen and other hormones), genetics alone–all contribute to the brown spots and sun spots. Generally, a brown spot is a focal area of either a higher number of pigment cells (called “melanocytes”) or an increased number of pigment molecules (called “melanin”) located within the melanocyte.
Some excess melanin resides in your top layer of skin, or epidermis. Some excess melanin is deeper, in the dermis. Thus, brown spots are really a diverse group of skin issues: different types of increased pigmentation require different lightening treatments.
Lasers remove the brown spots and patches from the skin by selectively targeting the melanin and melanocyte, leaving the other cells in the skin untouched. This unique feature is why these procedures are the safest and most effective treatment choice for removing brown sun spots from the skin. Certain lasers have been designed to just remove brown spots; these devices break up the excess melanin causing the discolorations.