Etiology is a doctor’s word with two close jobs. First, the cause of a disease — what started it. Second, the scientific study of those causes.

Etiology這個字 is是 a doctor's word醫生用的一個詞 with two close jobs.有兩個很接近的意思。 First,第一， the cause of a disease指一種病的病因 — what started it.——是什麼引起的。 Second,第二， the scientific study of those causes.指研究這些病因的科學。

You will see it in hospitals, research papers, and textbooks. American spelling is etiology; British spelling often keeps an extra a near the front: aetiology.

You will see it in你會在 hospitals, research papers, and textbooks醫院、研究論文和教科書裡看到這個字。 American spelling美式拼法 is是 etiology;etiology； British spelling英式拼法 often keeps an extra a near the front常常在前面多一個a: aetiology.寫成aetiology。

Though actually, outside medicine, academics sometimes use it more loosely for “the cause of this problem” — a war, a habit, a change in language. That use is real, but it still sounds very formal.

Though actually,不過其實， outside medicine在醫學之外 academics sometimes use it more loosely for學者有時候會比較鬆散地拿它來指 "the cause of this problem"「這個問題的起因」 — a war, a habit, a change in language比如一場戰爭、一個習慣、一種語言的變化。 That use is real,這種用法是真的存在， but it still sounds very formal.但聽起來還是很正式。

For most learners it is safest as a medical word. Ordinary people just say “the cause” or “why it happened.” It does not mean the treatment, and it does not mean the list of symptoms.

For most learners對大多數學習者來說 it is safest as把它當成醫學用詞 a medical word.最安全。 Ordinary people just say一般人就直接說 "the cause"「原因」 or或 "why it happened."「為什麼會這樣」。 It does not mean它不是指 the treatment,治療方法， and it does not mean也不是指 the list of symptoms.症狀清單。