Obesity and overweight
Obese people are prone to have dark inner thighs as when they walk, the thighs rub against each other. It creates a friction on the delicate thigh skin and affects the skin there. It also happens in people with heavier thighs in spite of having an average or well-built body
Too much exercise
When you involve in exercising too much, it affects the skin just like obese people. Rubbing of skin leads to dark inner thighs. Also, working out too much leads to sweating between the thighs, which affect the skin.
UV rays or Sun exposure
Those who love tanning or sun bathing while wearing a bikini on a beach are more likely to suffer from dark inner thighs. Although tanning through sun bathing provides gorgeous bronzed skin, many a times, it affects the parts with delicate skin, which includes inner thighs.
Bikini hair removal
Many young women who develop dark inner thighs are more likely to be the victims of the bikini hair removal methods. Inappropriate shaving or wrong bikini hair removal techniques certainly lead to darker skin on thighs, butt and back.