乱れる

1. Origins, structure, and basic meaning

• Structure: 乱れる(みだれる) means becoming disordered or losing a regular arrangement or rhythm.
• Basic usage: The examples describe hair becoming untidy in the wind and a sleep schedule becoming irregular.

2. Common pitfalls and similar expressions

• The change and its cause with 乱す
  • 髪が乱れる describes hair becoming disordered. 風が髪を乱す says that wind causes the change, using the transitive verb 乱す(みだす).