Encephalitis is a doctor’s word for swelling of the brain. The swelling is inflammation: the brain has become sore and puffed in the way a cut on your hand can become red and hot, but this is inside the head, so it is serious.

Encephalitis腦炎 is a doctor's word for是醫生用來說……的字 swelling of the brain腦部發炎腫脹 The swelling is inflammation這種腫是發炎 the brain has become sore and puffed腦部變得又痛又腫 in the way a cut on your hand can become red and hot就像手上的傷口會變紅、發熱一樣 but this is inside the head但這是發生在頭裡面 so it is serious所以很嚴重

Viruses are a common cause; other germs, or the body’s own defences going wrong, can cause it too. People may have a fever, a bad headache, confusion, or worse.

Viruses are a common cause病毒是常見的原因 other germs, or the body's own defences going wrong其他病菌，或身體自己的防禦系統出了問題 can cause it too也可能造成這種病 People may have患者可能會有 a fever, a bad headache, confusion, or worse發燒、頭痛得很厲害、意識不清，或更嚴重的狀況

You will hear it in hospitals and in the news when someone is very ill. It is not a casual word, and it does not mean an ordinary headache or feeling tired.

You will hear it你會聽到這個字 in hospitals and in the news在醫院裡，還有新聞裡 when someone is very ill當有人病得很重的時候 It is not a casual word這不是隨口用的字 and it does not mean也不是指 an ordinary headache or feeling tired普通的頭痛或覺得累

Though actually, swelling in everyday English can sound like a bump you can see. Here the swelling is inside, in the brain itself.

Though actually不過其實 swelling in everyday English日常英文裡的swelling（腫） can sound like a bump you can see聽起來像是看得見的一個腫塊 Here這裡（講的） the swelling is inside腫是在裡面 in the brain itself就在腦部本身