The basic test
To be covered, an injury or illness has to arise out of and in the course of your employment, meaning the work caused it and it happened while you were doing your job. That reaches well beyond dramatic accidents.
Sudden accidents
These are the clearest claims: a fall, a machine injury, a lifting injury, or a crash while driving for work. The cause and the date are easy to pin down, and reporting promptly keeps the claim clean.
Repetitive strain and occupational illness
Conditions that build up over time can qualify too: carpal tunnel from repetitive motion, a back worn down by years of lifting, hearing loss from constant noise, or lung problems from on-the-job exposure. For these, the clock generally runs from when you knew, or should have known, the condition was work-related.
Aggravation of a pre-existing condition
An earlier injury does not automatically disqualify you. When your job significantly worsens a condition you already had, such as a bad knee reinjured at work, that aggravation can be compensable, though insurers often dispute it.
What usually is not covered
Injuries during your ordinary commute, harm caused by your own intoxication, and injuries from horseplay you started are commonly excluded. Gray areas exist, so a borderline injury is not automatically denied; filing puts the facts in front of the Board.