失眠

You usually use it as a verb or a noun. You can say 我失眠了 to mean 'I couldn't sleep last night.' You don't need a lot of fancy grammar around it. It is a very self-contained expression. If it happens often, you can say 我经常失眠. It’s short, punchy, and everyone understands the pain immediately. Just don't use it if you stayed up late on purpose to play video games!

Use it when you are chatting with friends about why you look like a zombie. Use it in a doctor's office to describe a medical issue. It is perfect for those 3:00 AM social media posts. You can also use it to express that you are worried about something. If a big exam is coming up, you might say you are 失眠. It shows the level of your stress or excitement.

Avoid using 失眠 if you just stayed up late by choice. That is called 熬夜 (staying up late). If you say 失眠, people will feel sorry for you. If you actually just watched Netflix until 4:00 AM, that's not 'losing' sleep; that's 'spending' it. Also, don't use it in very high-level poetic contexts where you might want more flowery language. It is a bit too direct for a love poem.

In China, 失眠 is often linked to 'internal heat' or stress in Traditional Chinese Medicine. If you tell a Chinese friend you are 失眠, they might suggest drinking chrysanthemum tea. They might also tell you to soak your feet in hot water. It is seen as a sign that your life balance is a bit off. Recently, 'Insomnia Culture' has grown among young professionals in big cities like Shanghai. It’s almost a badge of honor for being a hard worker.

You will often hear 昨晚失眠了 (I had insomnia last night). Another common one is 习惯性失眠 (habitual insomnia). If you want to be more casual, you can say 整晚没睡着 (didn't sleep all night). But 失眠 remains the most efficient way to communicate the struggle. It sounds a bit more serious and 'official' than just saying you didn't sleep well.