Stretch marks (striae) are pink, red or purple indented streaks that often appear on the abdomen, breasts, upper arms, buttocks and thighs and eventually fade to white or gray. Stretch marks are particularly common in pregnant women, especially during the latter half of pregnancy. Treatment can make stretch marks fade, but it won't completely remove them. Symptoms Stretch marks don't all look alike. They vary depending on how long you've had them, what caused them and where they are on your body, as well as on the type of skin you have. Common variations include: Indented streaks or lines in the skin Multiple pink, red or purple streaks Bright streaks that fade to a light pink, white or grayish color Stretch marks are common on the abdomen, breasts, upper arms, buttocks and thighs. Sometimes they can cover large areas of the body. When to see a doctor See your doctor if you're concerned about the appearance of your skin or if the stretch marks cover large areas of your body. Your doctor can help determine the cause of the stretch marks and can discuss possible treatment options. Causes Stretch marks seem to be caused, literally, by a stretching of the skin. Stretch marks are more extreme when coupled with an increase in cortisone, a hormone produced by the adrenal glands. Cortisone weakens elastic fibers in the skin. Stretch marks develop in a variety of circumstances, including: Pregnancy. Most pregnant women develop stretch marks by the end of their pregnancy. The physical stretching of the skin, along with hormonal factors, likely plays a role. Weight gain. Stretch marks sometimes occur during substantial weight gain. Weightlifters can develop stretch marks, particularly on the arms. Adolescents may notice stretch marks during growth spurts. Medication use. Corticosteroid creams, lotions and pills and chronic use of oral or systemic steroids can cause stretch marks. Conditions or diseases. Cushing's syndrome and adrenal gland diseases can cause widespread stretch marks, as can Marfan syndrome, Ehlers-Danlos syndrome and other hereditary (genetic) disorders Risk factors Anyone can get stretch marks, but some factors increase your likelihood of getting them, including: Being female Having a family history of stretch marks Having been pregnant, especially for younger women Being overweight or obese Rapidly gaining or losing weight, as in the case of pregnancy Using corticosteroid medication [Broken External Image]:http://kidshealth.org/teen/your_body/beautiful/headers_90663/T_Stretch_marks_1.jpg source:http://www.mayoclinic.org/diseases-conditions/stretch-marks/basics/tests-diagnosis/con-20032624