A medical diagnosis: a doctor's determination of the cause or name of a disease or condition; also the result (the diagnosis).
検査の結果、医師はインフルエンザと診断した。
Based on the test results, the doctor diagnosed (me with) influenza.
正確な診断を下すために追加の血液検査を依頼された。
I was asked to take additional blood tests to reach an accurate diagnosis.
専門医の診断によって治療方針が決まった。
The treatment plan was decided based on the specialist's diagnosis.