Masturbation is a perfectly normal activity done in the privacy of one's room. Side effects should not exist unless the student has feelings of guilt or the activity becomes compulsive. Normally, masturbation can relieve feelings of depression, be sexual experimentation before a sexual experience with another person, and an expression of the person's own sexuality. Many churches see this as a sin; thus, the guilt factor is important for those who believe this is a sin. In medical terms, normal masturbation should not have side effects if engaged in a manner which is not obsessive such as many times a day. The reference I've included discusses when to call a doctor over masturbation which is really a limited situation. Relax, read the reference, and don't worry about side effects with masturbation. My only concern would be if someone were using this as a means of avoiding people and a normal life. As a 10th grader, this is normal sexual experimentation.