Stretch marks are a common skincare concern among many women, and no particular skin type or ethnicity is exempt from finding the pesky little narrow streaks on their breasts, stomach, thighs, hips and arms. It’s estimated that, as many as 80 percent of women develop stretch marks during pregnancy, and 70 percent of girls develop them during puberty—so know that you’re not alone in experiencing this beauty blight.

Here are the most common situations that can lead to stretch marks:

Pregnancy

Stretch marks are an extremely common side effect of pregnancy, particularly during the latter stages when the abdomen is rapidly expanding to accommodate a growing baby. While it’s hard to predict who will develop stretch marks during pregnancy, they are more likely to occur in women carrying multiple babies, bigger babies or those who are carrying excess fluid. Studies have also shown that the younger a woman is when she is pregnant, the more likely she is to develop stretch marks in pregnancy. Those whose family members developed stretch marks during pregnancy are also more likely to develop more noticeable stretch marks. Aside from gaining excessive weight during your pregnancy, you cannot prevent the onset of stretch marks. There are no creams that have been proven to prevent stretch marks or to improve them while you are pregnant. However, you can keep your stomach well moisturized with a cream that will help to soothe any itching that is often associated with pregnancy.

Puberty

Acne scars aren’t the only remnants of adolescence. During growth spurts, such as in puberty, the skin suddenly stretches, which can cause the middle layer of skin (the dermis) to break in places. This allows the deeper layers of skin to show through, which, in turn, results in visible stretch marks. While there is no quick fix to remove them, the color and appearance gradually fades, although doesn’t completely disappear, over time.

Fluctuating Weight

You could develop stretch marks if you gain weight quickly over a short period of time. However, when you begin to lose the weight, you should do so at a slow and steady pace to avoid putting your skin under additional strain. The same goes for those hitting the gym aggressively and weight training since you can develop stretch marks as your muscles quickly increase in size.

Other Causes

While most stretch marks can be attributed to rapid weight gain, some can be caused by rare underlying health conditions, such as Cushing’s syndrome. The syndrome occurs when the body overproduces the hormone cortisol, which is thought to lead to the development of stretch marks. Stretch marks may also develop after prolonged use of oral medications such as prednisone (a type of corticosteroid) or corticosteroid creams, which are commonly used to treat skin conditions such as eczema or poison ivy. When using such treatments, follow dermatologist or manufacturer instructions to limit potential side effects.