Typically a harmless condition, hyperpigmentation is the darkening of the skin or nails. Caused by an increase in melanin, hyperpigmentation usually occurs after skin has suffered some kind of damage, such as sun damage, inflammation, or acne vulgaris. Medical lasers can also cause it.

Melanin, which is responsible for the color of the skin, eyes, hair, and other areas of the body, is produced in the lower level of the epidermis by melanocytes. As the body ages, the distribution of melanocytes is less regulated and easily affected by other factors, such as UV light. When the skin is exposed to ultraviolet light, melanocytes are stimulated. In areas of the skin where concentrations of the cells are more concentrated, hypopigmentation will occur, making the skin look blotchy with dark spots. Another form of hyperpigmentation is post-inflammatory hyperpigmentation, or the annoying dark spots that appear after acne heals.

Bleach is a popular treatment that is used to lighten the skin until it matches the person’s natural skin tone. Prescription bleach works faster than over-the-counter products, but it can cause severe skin irritation and sensitivity.

While hyperpigmentation is a possible side effect of laser tattoo removal, certain medical lasers can treat the condition. When performed by a licensed medical technician, laser treatment can remove the extra pigment without leaving a scar.