Dissociative disorder can cause your teen to lose her short-term or long-term memory. This disorder occurs when your teen experiences a traumatic event--it's a coping response to block memory. Lack of Oxygen. When your teen's brain doesn't receive a sufficient supply of oxygen, it may affect his memory.When to see your doctor about memory loss?
If your memory loss and its symptoms interfere with your daily life, or if you have other symptoms of potential causes, you should definitely see your doctor. Short-term memory loss is a normal part of aging for many people, but this type of memory loss generally doesn’t create any problems with living or functioning independently.