烦恼 (fán nǎo) is a compound noun meaning 'trouble,' 'distress,' or 'mental anguish' — the kind of persistent, low-level worry or irritation that weighs on one’s mind. The first character 烦 (fán) conveys restlessness, impatience, or annoyance; the second, 恼 (nǎo), means 'to vex' or 'to distress.' Together, they emphasize an internal emotional state rather than external problems — it’s not just 'a problem' but the *feeling* of being troubled by it.

This word is commonly used in everyday speech and writing to describe personal, subjective unease: stress about work, relationship doubts, or existential uncertainty. It often appears with verbs like 有 (yǒu, 'to have'), 解决 (jiě jué, 'to resolve'), or 减少 (jiǎn shǎo, 'to reduce'), and can be modified by adjectives like 无尽的 (wú jìn de, 'endless') or 深重的 (shēn zhòng de, 'deep-seated'). While it can refer to minor irritations, it more often signals something emotionally significant and lingering.