I often hear patients complain that they suffer from hyperpigmentation. So what exactly is hyperpigmentation? In fact, skin pigmentation is only a symptom and not a diagnostic term for a disease. Hyperpigmentation can be seen in many dermatological diseases, and dermatology refers to diseases with hyperpigmentation as the main manifestation as hyperpigmented skin diseases. The pathogenesis of this group of diseases is no more than an increase in the number of melanocytes or their increased activity. In terms of etiology, they can be divided into genetic (freckles), endocrine (melasma), metabolic (Reye’s melanosis), drug (fixed drug rash), inflammatory (sun spots), neoplastic (nevi), physical (frictional melanosis) and artificial (tattoos). Except for tumor diseases, which are caused by absolute increase in the number of melanocytes, most of the other diseases are caused by abnormal metabolism of melanocytes. The treatment of skin pigmentation should naturally be based on two aspects, one is the treatment for the cause, and the other is the local symptomatic treatment. The latter is the use of physical or chemical methods to get rid of local pigmentation. From the above analysis of the etiology of hyperpigmentation, it is easy to see that genetic and neoplastic diseases have clear etiology and are less affected by internal factors, and local treatment can mostly achieve satisfactory results. Common types of diseases include various types of pigmented nevi, spotted nevus blue nevus, nevus of Ota, etten nevus, pigmented gross epidermal nevus, coffee spot, freckle, age spot and so on. The medical profession has explored health for a long time and searched for a variety of treatment methods. In ancient times in China, there are records of using special herbal medicine internally or externally to treat pigmented diseases such as what modern medicine calls nevus of Ota. Surgical excision or chemical peeling therapy has also been applied at home and abroad for a long time. With the continuous development of physical therapy, liquid nitrogen cryotherapy, superficial radiation or isotope therapy and traditional laser therapy have been applied to the treatment of such diseases and have been used until now. Although doctors have been trying to improve these treatments over the years, unfortunately, these treatments are not always available. However, unfortunately, the above-mentioned treatments have greatly limited their application in the treatment of skin pigmentation diseases either because of their low efficacy or because of their own inevitable adverse effects, such as scar formation, pigmentation changes, or even local atrophy and deformation. In 1983, foreign countries first proposed the theory of selective photothermal effect, that is, different wavelengths of laser can selectively act on different colors of skin damage, especially the application of Q modulation technology can shorten the duration of output pulse to nanosecond level. This has opened up a new era of laser medicine. With this principle, the United States, Britain and other countries developed new short pulse laser in the rib era, making a new breakthrough in the treatment of skin pigmentation diseases. This kind of laser treatment instrument, with its powerful instantaneous power, highly concentrated radiation energy and pigment selectivity, and extremely short pulse width, enables laser energy to focus on pigment particles, vaporize or break them up directly, and discharge them out of the body through lymphatic tissues without affecting the surrounding normal tissues, thus achieving the good effect of exact efficacy, no damage, no scar, little pain and safe and easy treatment. Photorejuvenation is a non-surgical, non-exfoliating, non-invasive, non-invasive physical therapy. With its unique broad-spectrum pulses, photorejuvenation reaches the deeper layers of the skin through the epidermis to improve skin imperfections and restore your skin’s elasticity and youthfulness. It lightens pigmentation (e.g. freckles, sun spots, age spots, chloasma), eliminates dull skin tone, removes facial capillary dilation, shrinks pores, increases skin elasticity, fights skin aging, smooths superficial wrinkles, treats acne, etc., and improves skin quality in a comprehensive manner. After a few treatments, you can notice a significant reduction in facial pigmentation, smooth and elastic skin, and the disappearance of wrinkles. This treatment can also be used efficiently on other parts of the body such as the neck, chest and arms.