There are many kinds of pigmentation spots, such as chloasma, freckles, seborrheic keratosis, etc. All the above diseases may lead to the formation of pigmentation spots on the skin. 1. Melasma: mainly manifested as yellow-brown pigmentation spots, symmetrically distributed, with different shapes of lesions, which may be round, butterfly-shaped or strip-shaped. Its etiology is not yet clear, and it may be related to heredity, changes in sex hormone level, ultraviolet radiation and other factors. 2. Freckles: The causes of this disease are mostly related to heredity, light exposure and other factors. Patients will have light brown to dark brown spots on the skin, and the lesions are mostly round or ovoid in shape. 3. Seborrheic keratosis: mainly manifested as spots, plaques or flat papules of different sizes, mostly attached to the surface of the skin and raised on the skin. The cause of this disease may be caused by skin aging, gene mutation and heredity. There are many reasons that lead to the formation of pigmentation on the skin, and there are also a variety of pigmentation increase diseases related to liver and endocrine diseases, it is recommended to go to a regular medical institution for a relevant examination to clarify the cause, so as not to delay the treatment.