Hyperpigmentation is a non-medical term that refers to a darker-than-normal skin color. It may be caused by several factors that depend on the hyperpigmentation you are experiencing. There are many things that can cause hyperpigmentation including:
Exposure to the Sun
Regularly expose your skin to prolonged sunlight, and then your body will produce more melanin in an attempt to protect you. This can cause dark spots on your skin called age spots or sun spots.
Inflammation of the Skin
Inflamed areas of the skin can darken in color. This can occur in a number of diseases, including acne, eczema, and lupus.
Melasma
Hormonal changes can cause dark patches of skin. Pregnant women experience this type of hyperpigmentation frequently.
Medicinal Reactions
Some medications, topical treatments, and even chemicals in foods can cause hyperpigmentation.