How do people get stretch marks?

People get stretch marks when the skin stretches too much, according to Mayo Clinic. One of the most common causes of stretch marks is pregnancy.

There are numerous ways a person can get stretch marks:

• During pregnancy the skin stretches to accommodate the growing uterus. While not all pregnant women get stretch marks, most do. Hormonal changes exacerbate the process.
• When a person gains weight he or she may develop stretch marks. This is also true for bodybuilders, who build their body mass.
• People who use corticosteroids and creams are at higher risk of developing stretch marks.
• Certain conditions cause stretch marks. This includes Cushing's syndrome and some adrenal gland diseases, as well as Marfan syndrome and Ehlers-Danlos syndrome.
• Being female and having a family history of stretch marks means a person is more likely to develop them.
• Rapidly gaining and losing weight is another risk factor.

Stretch marks are most likely to appear on the hips, belly, thighs, upper arms and back, according to WebMD. They arise when the dermis, or the skin's middle layer, stretches too much, causing it to break down and leave a mark behind. Although there are ways to treat stretch marks, none are 100 percent effective. Some treatment methods include surgery and lotions containing Retin-A or Tazorac.