Why do stretch marks develop?
Stretch marks can develop in the context of pregnancy, adolescent growth spurts, weight gain or loss, or bodybuilding.16
Hormonal influences, mechanical stress and genetic predisposition have been proposed as contributing factors. Their relative roles are not fully understood.16
Studies have reported associations with weight gain and changes in body size, but findings vary between populations.16
The different types of stretch marks
Striae Distensae is the generic term for stretch marks, but there are several different classifications:10
How stretch marks develop
Stretch marks are a type of thin, flattened scar.10
Stretch marks are common
The reported prevalence of Striae ranges between 50–90%, with most control groups showing between 60% and 70% developed during pregnancy, depending on the population studied.1
- 2.5×
- A review by Elsaie et al. (2009) reported stretch marks to be around 2.5 times as frequent in women as in men. This review-reported comparison is not a universal estimate for every population.10
- 60–70%
- The reported prevalence of Striae ranges between 50–90%, with most control groups showing between 60% and 70% developed during pregnancy, depending on the population studied.1
Where can stretch marks appear?
Stretch marks commonly occur on the abdomen, breasts, hips and thighs; their location can vary.10
