悪化

1. Origins, structure, and basic meaning

• Structure: 悪化 is read as あっか and is a noun for deterioration in a condition, situation, or relationship; with する, it also means to worsen.
• Basic usage: Use 情勢が悪化する for a situation worsening and 関係の悪化 for deterioration in a relationship.

2. Common pitfalls and similar expressions

• Difference between 悪化 and 低下
  • The former describes an overall change for the worse, whereas the latter specifically indicates that a level, value, or ability has gone down.