Understanding Moles Moles, or melanocytic nevi in medical terms, are common skin features caused by an increase in melanocytes within the epidermis and dermis. While the sudden appearance of moles is often a normal physiological occurrence, it can also signal certain health conditions or diseases. Here’s a detailed explanation: Most people have moles on their bodies, which can be present from birth or develop later in life. The development of moles over time is usually related to factors such as genetics and exposure to ultraviolet (UV) rays, which are normal biological changes and should not be a cause for excessive... Learn more