What are the dark-yellow or brown spots that appear on the skin as a result of aging known as?

The term "senile lentigines" refers specifically to the dark-yellow or brown spots that develop on the skin due to aging and prolonged sun exposure. These spots are commonly referred to as age spots. They typically appear on areas of the skin that have been exposed to the sun, such as the face, hands, shoulders, and arms.

The pigmentation in senile lentigines results from an increase in melanin production, which is triggered by sun exposure over time. This is a normal part of the aging process and is often seen in older adults. While "age spots" is a more general term that people often use interchangeably with senile lentigines, the latter is the more medically-specific term that describes these types of skin discolorations.

Other terms like freckles or melanomas do not apply here as freckles are typically found in younger individuals and are not solely associated with aging, while melanomas refer to a serious form of skin cancer, which differs fundamentally from benign age-related skin changes.