被 + 诊断 + 为 + Condition
诊断 (zhěnduàn) means "to diagnose" as a verb or "a diagnosis" as a noun. It is used in medical contexts to describe identifying an illness or condition. Common phrases include 被诊断为 (to be diagnosed with) and 做出诊断 (to make a diagnosis).
医生诊断他得了流感,需要休息几天。
Yīshēng zhěnduàn tā dé le liúgǎn, xūyào xiūxi jǐ tiān.
The doctor diagnosed him with the flu and said he needs to rest for a few days.
这个病很难诊断,他跑了好几家医院。
Zhège bìng hěn nán zhěnduàn, tā pǎo le hǎo jǐ jiā yīyuàn.
This illness is hard to diagnose; he went to several hospitals.
检查结果出来后,医生才能做出准确的诊断。
Jiǎnchá jiéguǒ chūlái hòu, yīshēng cái néng zuòchū zhǔnquè de zhěnduàn.
The doctor can only make an accurate diagnosis after the test results come out.