Detailed answer

Stretch marks, also known as striae, can indeed occur on the upper back. Stretch marks form when the skin is stretched or undergoes rapid changes in growth. This commonly happens during periods of rapid weight gain or growth, which can occur on the upper back due to factors such as muscle development or weight fluctuations. These stretch marks appear as thin, raised lines on the skin and may vary in color from pink to purple or even white. While they are a common occurrence, especially in individuals with certain skin types or genetic predispositions, there are various treatments available to help improve the appearance of stretch marks on the upper back if desired, such as topical creams, laser therapy, or microdermabrasion.