副作用

Using it is super simple. You usually say something 'has' side effects using 有. For example, 这个药有副作用. If you want to say the side effects are huge, just add 很大. You can also use it metaphorically. If you work too hard and your social life suffers, that is a 副作用 of your ambition. It functions as a noun in almost every sentence.

You will hear this at the doctor's office constantly. It is the standard medical term. However, use it when discussing consequences of decisions too. Use it when talking about technology, new laws, or even lifestyle changes. It sounds smart but is common enough for a casual chat over bubble tea. It’s perfect for when you want to complain about a 'catch' in a situation.

Don't use it for purely positive surprises. If you bought a lottery ticket and met your soulmate at the kiosk, that's not a 副作用. That is just 'good luck' or an 'extra benefit' (额外好处). Also, avoid using it for direct, intended results. If you hit a wall and your hand hurts, that’s just a result, not a side effect. Keep it for the 'unintended' stuff.

In China, there is a huge focus on 'balance' in health. Traditional Chinese Medicine (TCM) often claims to have fewer 副作用 than Western medicine. Because of this, people are very sensitive to this word. You’ll often see it on food packaging or health supplements. It’s a word that carries a bit of caution and skepticism.

You might hear 后遗症 (hòuyízhèng) which means 'sequel' or 'lingering effect.' That one is usually more serious, like a long-term scar. 副作用 is usually temporary. If you want to be very formal in a business report, you might use 负面影响 (negative influence), but 副作用 is much punchier for daily life.