Brown spots can be caused by a variety of factors, ranging from excessive sun exposure to rashes. They can vary in shape, size, color and texture and be a sign of aging, possible illness or simply genetic influences.
According to the Mayo Clinic, liver spots are also known as solar lentigines or age spots. Liver spots are occur due to overexposure to the sun and occurs mostly in the older population.
Mayo Clinic dermatologist Lawrence E. Gibson states that freckles are caused due to sun exposure and appear as pigmented spots. They tend to develop on light skin, and the color ranges from reddish to brownish.
According to the Skin Cancer Foundation, new growths on the skin and changes to existing moles may be a sign of melanoma, a serious form of skin cancer. Overexposure to the ultraviolet rays (UVA and UVB) from the sun or tanning beds, type of skin, genetics and a number of pre-existing moles on the skin are the main factors associated with the risk melanoma.
The American Academy of Dermatology states that pityriasis rosea is a skin rash commonly found in people from 10 to 35 years of age. The cause of this rash is unknown, although recent evidence point to a virus.
Actinic keratosis is a precancerous condition that can develop into invasive squamous cell carcinoma (SCC). The closer a person lives to the equator, the more their chances of having actinic keratosis. It can take years to develop, and it's generally found in the older population.