Detailed answer

Stretch marks can develop on the upper arms. They commonly occur due to rapid weight changes, such as weight gain or muscle growth. The stretching of the skin causes the collagen and elastin fibers to break, leading to the formation of stretch marks. Additionally, hormonal changes during puberty or pregnancy can also contribute to the development of stretch marks on the upper arms. People who engage in weightlifting or bodybuilding may be more prone to developing stretch marks in this area due to the rapid increase in muscle mass. Applying moisturizers and creams rich in collagen-boosting ingredients, maintaining a healthy diet, and staying hydrated can help improve the appearance of stretch marks on the upper arms.