California law defines a work injury as any injury arising out of employment, or sustained in the course of employment, which requires medical treatment beyond first aid. Generally, if (1) you are an employee, (2) have sustained an injury, and (3) the injury occurred during the course of employment, you are entitled to various types of workers' compensation benefits, including medical treatment, wage loss benefits, permanent disability benefits, and potential job displacement benefits. However, there are time limitations for filing your claim, and there are defenses available to the employer which may bar your right to benefits. Every case is different. It is imperative that you consult an attorney as soon as possible if you have sustained, or think you have sustained, an injury at work.