Hyperpigmentation is one of the most common conditions around the world. It is usually harmless condition in which patches of your skin become darker in color than the normal surrounding skin. This darkening is happening when an excess of melanin forms deposits in the skin. Melanin is brown pigment which is producing normal skin color. Hyperpigmentation can affect the color of the skin of all people no matter which race they are.  Liver or age spots are one of the most common forms of hyperpigmentation. They can happen due to sun damage and they are referred by doctors as solar lentigines.  These are small and darkened patches which are usually found on your face and hand or other areas of your body which are frequently exposed to the sun. Sun exposure is the most common cause for hyperpigmentation because the sunlight can trigger the production of melanin. Melanin is acting as our natural skin sunscreen and it is protecting us from the harmful UV rays and this is a reason why people tan in the sun. [1,2]
Symptoms of hyperpigmentation: The only symptoms of hyperpigmentation are darkened areas of the skin. Patches can be in various sizes and they can develop anywhere of our bodies.
Causes for hyperpigmentation
The excess production of melanin is the most common cause for hyperpigmentation. Melanin is a pigment which gives our skin the color. Melanin is produced by the skin cells called melanocytes. There are several factors or conditions which can alter the production of melanin in the body. There are also certain medications which can cause hyperpigmentation. Also it is known fact that some chemotherapy drugs can cause hyperpigmentation as a side effect.  Also in some women the pregnancy change hormone levels can affect the melanin production.  A lot of sun exposure can also lead to increase in the melanin. Pigment spots, such as age spots, are caused by the sun exposure. This is a reason why they appear on those parts of our bodies which are frequently exposed to sun such as arms, hands and face. [1,2] Pigment spots tend to be small and darkened patches of our skin. Also there are other factors which cause patches of your skin to become darker, such as skin cancers, solar or actinic keratoses, birthmarks and moles but these forms are not considered as forms of hyperpigmentation. If you are concerned about any of your dark spots or if you have noticed that new dark spots are starting, then you should talk with your doctor. Also you should visit your doctor if your spots start to itch, bleed or change in color or size.
Types of hyperpigmentation
There are known several types of hyperpigmentation and they include:
- Post – inflammatory hyperpigmentation: This type of hyperpigmentation is a result of an injury to the skin. This condition is happening when a skin injury or trauma heals and it leaves a flat area of discoloration behind. This condition is commonly found among acne sufferers and also it can be caused by cosmetic products such as chemical peels, laser treatment and dermabrasion.
- Sunspots: They are also known as solar lentigines. They are very common type of hyperpigmentation. This type of hyperpigmentation is related to excess sun exposure over time. They appear as spots of hyperpigmentation on areas of our skin which are exposed to the sun such as face and hands.
- Melasma: Melasma is also known as cholasma. This type of hyperpigmentation is caused by hormonal changes and it can develop during pregnancy. It is often referred to as the mask of pregnancy because it affects 90% of the pregnant women. This type of hyperpigmentation is happening as a result of hormonal influences such as birth control pills and pregnancy. Areas of hyperpigmentation can appear on any area of your body. It causes dark and irregularly shaped areas on your arms and face which can be quite large. They most common appear on the face and abdomen. 
Risk factors for hyperpigmentation: As we have said, the sun exposure can increase the melanin production. When you have greater exposure to the sun, then it can increase your risk of developing hyperpigmentation. [1,2]
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 Bonilla C, Ness AR, Wills AK, et al. Skin pigmentation, sun exposure and vitamin D levels in children of the Avon Longitudinal Study of Parents and Children. BMC Public Health. 2014.
 Dai J, Belum VR, Wu S, et al. Pigmentary changes in patients treated with targeted anticancer agents: a systematic review and meta-analysis. Journal of the American Academy of Dermatology. 2017;77(5):902–10.e2.
 Fernandes LB, do Amaral WN. Clinical study of skin changes in low and high risk pregnant women. Anais Brasileiros de Dermatologia. 2015;90(6):822–6.
 Ogbechie-Godec OA, Elbuluk N. Melasma: an up-to-date comprehensive review. Dermatology and Therapy. 2017;7(3):305–18.