Aggravation of a Previous Injury or Illness

You may be responsible under workers’ compensation benefits for an injury to an employee if that employee’s prior non-industrial medical condition was aggravated by their employment.

For example, the Workers’ Compensation Appeals Board (WCAB) has held that the employer is responsible for increased disability caused by work activity, even if the underlying disease process pre-existed the employment.¹

In essence, the employee comes to the employment relationship with their pre-existing history and medical conditions. Therefore, the employer may be liable for benefits if the