Only specifically speaking about FMLA, and not disability ꟷ the FMLA does not require that a diagnosis be provided. A serious health condition is determined by the regimen of treatment that a claimant is undergoing.

The FMLA defines a serious health condition as an illness, injury, impairment, or physical or mental condition that involves either inpatient care or continuing treatment by a health care provider. Both physical and mental health conditions qualify for FMLA leave.

The regulations provide very specific definitions of treatments that qualify, but based on the information you provided, your situation sounds like it could fall under either “incapacity plus treatment,” or “inpatient care.”

Incapacity plus treatment involves a period of incapacity of more than three consecutive, full calendar days with follow-up treatment. To qualify as a serious health condition under the FMLA, the employee or the employee’s family member experiencing the period of incapacity must also:

• Be treated by a health care provider within seven days of the first day of incapacity, and,
• Be prescribed a course of treatment by a health care provider (e.g., a course of prescription medication), or,
• Have at least one other visit with a health care provider within 30 days of the first day of incapacity.

Inpatient care under the FMLA means an overnight stay in a hospital, hospice, or residential medical care facility, including any period of incapacity or any subsequent treatment in connection with the overnight stay.