腫れる

1. Origins, structure, and basic meaning

• Structure: 腫れる, read はれる, uses the swelling stem 腫 in an intransitive verb describing a change of state.
• Basic usage: It is an intransitive verb for a body part swelling, as in 腕が腫れる.

2. Common pitfalls and similar expressions

• Grammar and combinations
  • The swollen body part takes が; the verb does not itself express someone causing the swelling.