Causes of skin discoloration include sun overexposure, certain medications, an overload of iron, certain fungal infections, or a history of skin inflammation, according to MedlinePlus. The condition of having dark blotches in the skin is referred to as hyperpigmentation, while the condition for light blotches is called hypopigmentation.
In most cases, skin discoloration is not an indication of a serious medical condition, says MedlinePlus. The discoloration is caused by skin either producing too much or too little melanin, the substance that gives the skin color. Independent of other symptoms, hyperpigmentation and hypopigmentation are not conditions that need serious attention.
It's possible to treat skin discoloration with creams that slightly shift the color of the skin to match the area around it, says MedlinePlus. Contact a doctor if the discoloration is of great concern, especially if the condition is persistent or if the affected area changes in size, shape or color.
At an appointment to evaluate skin discoloration, a physician may perform a hormone test, a skin biopsy, a study of the thyroid, or a Wood's lamp test, according to MedlinePlus. If the condition requires treatment, the doctor may recommend creams, ointments, surgery, or phototherapy, depending on the patient's specific situation.