subject to a medical analysis
"The doctor spent an hour examining my symptoms before diagnosing me with the flu."
To determine which disease is causing a sick person's signs and symptoms; to find the diagnosis.
"The doctor examined the patient's fever and rash before diagnosing her with measles."
In plain English: To diagnose something means to figure out exactly what is wrong with it, usually by checking its symptoms and deciding on the right treatment or fix.
"The doctor needs to examine me closely before she can diagnose my illness."
Usage: Use diagnose when you are actively determining the cause of an illness based on observed symptoms, rather than simply stating that someone has been diagnosed with a condition. This verb typically requires a direct object referring either to the patient or the specific disease being identified.
The word diagnose is a back-formation created by removing the suffix "-sis" from the noun diagnosis. It entered English as an action verb derived directly from that existing medical term.