A diagnosis is the medical term used to identify the cause and nature of a person's medical condition. Physicians may evaluate a patient's symptoms and use medical tests (lab tests, MRIs, XRAYS, etc.) to determine the correct medical diagnosis. The Social Security Administration may review a claimant's diagnosis and resulting symptoms to determine if a claimant's mental or physical health condition meets or exceeds a condition outlined on the Social Security Administration List of Impairments. Conditions which meet the SSA List of Impairments will be considered so severe that a Social Security Disability claimant is unable to perform substantial gainful activity. If a disability claimant does not have a medical diagnosis that matches a Social Security Administration List of Impairments, the diagnosis of the claimant's condition becomes less important and the Social Security Administration will instead focus on the claimant's mental or physical residual functional capacity to perform work.