An employer takes the employee as is and is responsible for medical conditions caused or made worse by employment. An injury or disease must occur while carrying out the interest of the employer. The actual injury or disease does not have to occur on the employer's premises to be covered by workers' compensation.
The word "injury" under the Workers' Compensation Act means more than it does in every day speech. For workers' compensation purposes, the following situations are considered injuries:
- A specific incident at work causing an injury, i.e.: "Fall at work" is the most common.
- A series of repetitive actions resulting in a disability, i.e.: Carpal Tunnel Syndrome.
- A pre-existing condition that has been aggravated by work. i.e.: Asthma.
- An earlier work related disability which recurs causing a later disability, i.e.: Back injury.
Some diseases related to certain occupations are recognized specifically as occupational diseases.
- Tuberculosis and hepatitis for nurses, blood processors, and related professionals who are exposed to these diseases.
- Disease of the heart and lungs for firemen who have four or more years of service.
- Pneumoconiosis and silicosis for any occupation that involves direct contact with or exposure to coal dust.
- Specific types of chemical poisoning (i.e.: lead, arsenic, mercury) for occupations that involve direct contact or exposure, or to the preparation or compounds.
Other diseases not specifically mentioned can be compensable if they meet certain criteria for determining whether a disease is occupationally related. The determination if a disease is compensable depends on the following:
- The employee is exposed to the disease by reason of his/her employment.
- The disease is causally related to the employee's industry or occupation.
- The occurrence of the disease is substantially greater in that industry or occupation than it is in the general population.