Traumatic brain injury (TBI) is a worldwide public health problem. Populations with a growing number of vehicles are experiencing many traumas and accidents. The highest-risk group is young men. Significant advances in neurosurgery and intensive therapy have resulted in increased survival rates of TBI patients. These higher survival rates, in turn, have led to an increasingly higher number of patients with neurological, cognitive, clinical, and social problems. This lack of knowledge about TBI has been called by some “the silent epidemic”. In recent years, studies of patients with moderate and severe TBI are increasing. Glasgow Coma Scale ≤ 8 and abnormal pupils at admission are used to determine the prognosis of patients with moderate or severe TBI. Several biomarkers such as interleukins, thiobarbituric acid reactive species, and some hormones have been studied in an effort to aid prognosis. Testosterone plays a key role in men. Thus, an understanding of androgens in TBI is essential to follow these survivors of head trauma. This review will discuss the epidemiology of TBI, its association with male hypogonadism, and possible treatments.