Final answer:
A macule is a flat, discolored spot on the skin that is less than 1 centimeter in diameter.
Step-by-step explanation:
A macule is a flat, discolored spot on the skin that is less than 1 centimeter in diameter. The cause of a macule can be excessive sun exposure, which can damage the cellular structure of the skin and lead to the irregular accumulation of melanocytes.
This can result in the appearance of freckles or larger masses of melanocytes called moles. However, it is important to note that not all macules are caused by excessive sun exposure. Other factors such as viral infections, genetic factors, or hormonal changes can also contribute to the development of macules.