serious health condition

Definition from Nolo’s Plain-English Law Dictionary

Under the Family and Medical Leave Act (FMLA), eligible employees may take leave for their own serious health condition or to care for a family member with a serious health condition. A serious health condition is an illness, injury, impairment, or physical or mental condition that involves (1) inpatient care; (2) incapacity for more than three full days with continuing treatment by a health care provider; (3) incapacity due to pregnancy or prenatal care; (4) incapacity due to, or treatment for, a chronic serious health condition; (5) permanent or long-term incapacity for a condition for which treatment may not be effective, such as a terminal illness; or (6) absence for multiple treatments for either restorative surgery following an injury or accident, or a condition that would require an absence of more than three days if not treated.

Definition provided by Nolo’s Plain-English Law Dictionary.