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.
Jan. 10, 2013