A review of relevant literature illustrates the expected resolution of minor head injury symptoms within 3 months. Diagnosis is complicated in less than 10% of patients with persistent symptoms that are primarily subjective and difficult to distinguish from base rates of normal noninjured population. Symptom invalidity and premorbid emotional and stress factors become a critical issue. This had led to disagreement in diagnostic standards. Criteria for four subsets of the diagnosis are offered along with assessment standards.