Sun burn is a major cause of skin pigmentation. sunlight significantly damages skin cells. these damaged skin cells produces more melanin into skin.
Another disease condition that is called Vitiligo. Vitiligo is responsible of patches of skin.
Genetic condition and its impact on skin
Some genetic condition can impact on skin in severer range. Albinism is such kinds of genetic condition that significantly impacts on skin. Due to the effect of albinism skin get no color condition. Some of the time the condition of colour of skin is lighter than the normal color may defined as the albinism.
Hyperpigmentation
Hyperpigmentation is a condition that refferes as a dark spot of skin surrounded by the lighter skin. It is a result of over melanin condition in a specific part of skin. hyperpigmentation are found mostly in old age. Though, in any age people can suffer with hyperpigmentation.
In women, there have some common cause of hyperpigmentation. Pregnency is one of the most common cause of hyperpigmentation.