Miss this term, and a serious work-related illness can get treated like bad luck instead of a job-caused injury - which can mean delays, denied benefits, or the wrong kind of claim. An occupational disease is an illness or medical condition caused by exposures, hazards, or repeated duties connected to a person's work. It often develops over time rather than from one sudden accident. Common examples include lung disease from dust or chemicals, hearing loss from noise, skin conditions from irritants, and repetitive stress problems from constant motion.

That matters because proving an occupational disease usually depends on showing a link between the job and the illness. In a toxic exposure case, that may involve work history, medical records, expert opinions, and evidence of what substances were present. In other situations, the key issue is whether the condition came from ordinary life or from the worker's particular job duties. That distinction can affect workers' compensation, a personal injury claim, and who may be legally responsible.

In New York, occupational disease claims are handled under the Workers' Compensation Law. Under New York Workers' Compensation Law § 28, a claim generally must be filed within two years of the disablement and within two years of when the worker knew or should have known the disease was related to the employment. That rule can be critical for illnesses that surface long after exposure, including chemical-related conditions or repetitive stress injuries in physically demanding jobs.