不安

1. Origins, structure, and basic meaning

• Structure: 不安 is read as ふあん and is a noun and adjectival noun for anxiety, unease, or feeling unsettled about a situation or the future.
• Basic usage: A worried state appears in 将来が不安だ, while a resulting reaction appears in 不安で眠れない.

2. Common pitfalls and similar expressions

• Noun and adjectival noun
  • The feeling appears in 不安を感じる, while 不安だ states that someone feels uneasy about a person, situation, or prospect.
• Difference from 心配
  • 心配 often concerns a specific person or problem; 不安 can also cover a diffuse sense of unease without a clearly defined cause.