Melasma, sun damage, post-inflammatory hyperpigmentation, freckles, and moles are the most common types of hyperpigmentation.

Melasma

Melasma is a common skin problem. The condition causes dark, discolored patches on your skin. It's also called chloasma, or the “mask of pregnancy,” when it occurs in pregnant women. The condition is much more common in women than men, though men can get it too.

Sun damage

Sun exposure can significantly damage human skin. The sun's heat dries out areas of unprotected skin and depletes the skin's supply of natural lubricating oils. In addition, the sun's ultraviolet (UV) radiation can cause burning and long-term changes in the skin's structure. The most common types of sun damage to the skin are: Dry skin , wrinkles, fine lines, age spots , Sunburn and Actinic keratosis a long-term changes in the skin's collagen (a structural protein).

Post-inflammatory hyperpigmentation

Post-inflammatory hyperpigmentation is darkening of the skin in an area of prior injury or skin disorder from increased pigment (melanin) left from the healing process. Sometimes the darkening may also be due to an iron pigment left behind when old red blood cells die. Acne is a common cause as well as any type of skin injury (scrapes, cuts, burns, insect bites, or chronic rubbing) or many other skin disorders, such as eczema (atopic dermatitis).

Freckles

Freckles are small brown spots on your skin, often in areas that get sun exposure. In most cases , freckles are harmless. They form as a result of overproduction of melanin, which is responsible for skin and hair color (pigmentation). Overall freckles come from ultraviolet (UV) radiation stimulation .

Moles

Moles are a common type of skin growth. They often appear as small, dark brown spots and are caused by clusters of pigmented cells . Moles generally appear during childhood and adolescence. Most people have 10 to 40 moles ,some of which may change in appearance or fade away over time. They're usually nothing to worry about unless they change size, shape or colour. UV light from the sun can increase the chance of a mole becoming cancerous. If you have lots of moles, you need to be extra careful in the sun.