Stretch Marks Causes

Stretch marks can occur anytime that your body expands faster than your skin can grow. This happens often during pregnancy, when your belly is rapidly expanding to accommodate baby inside. It can often happen to youth during growth spurts, to bodybuilders increasing their muscle mass and to anyone who experiences a rapid weight gain.

Pregnancy Stretch Marks

Stretch marks affect 50 to 90 percent of pregnant women. Most stretch marks appear on a pregnant woman's abdomen from about the six-month mark onward, when her belly is rapidly expanding to accommodate her growing baby and her skin is stretched to its limit. Some women also get them on their buttocks, thighs, hips, upper arms, lower back or breasts. They tend to be concentrated around the areas that store the most fat and do the most stretching.

When skin and underlying tissue pull and stretch beyond their ability to give, the collagen deposits located deep in the tissues break apart. At these times, the skin actually rips and tears. The tiny tears heal, resulting in scar tissue. Stretch marks often appear as small, red, pink, purple or dark brown depressed streaks in the skin, ranging in width from 1/10 of an inch to 4 inches. Stretch marks are most noticeable in the beginning, but after delivery the marks may gradually flatten out and lose their color.

Your chances of getting stretch marks can be influenced by many factors. Genetics play a major role in whether or not you will get stretch marks. If your mother or sister got them during pregnancy, you may be more likely to get them yourself. Besides genetic history, other factors include: ethnicity and skin tone (fair-skinned women tend to get them more), nutritional history (a sensible diet helps skin to stretch better), skin condition (dry skin tends to be less elastic than well-nourished skin) and the amount of weight gained during pregnancy (also how rapidly it was gained). If you are carrying multiples, carrying a large baby, have excess amniotic fluid or are naturally thin or small, you may have a higher-than-average incidence of stretch marks.

Puberty Stretch Marks

Stretch marks are common when going through puberty for both boys and girls. Young women can quickly develop purplish or reddish lines on their breasts, thighs, hips and buttocks. Boys can develop stretch marks as well when they quickly gain weight in different areas of their bodies.

Weight Gain Stretch Marks

Rapid weight gain can cause stretch marks in all age groups. When the skin does not have enough collagen or it is disrupted and grows too quickly, stretch marks or scars form. Bodybuilders frequently get stretch marks due to their rapidly changing bodies. In addition, skin creams with steroids in them can cause stretch marks when used for extended periods of time.