noun, noun or participle which takes 'suru', intransitive verb
aggravation; exacerbation; worsening
Used for a medical condition becoming more serious; often appears in news and health contexts.
インフルエンザが重症化すると肺炎を引き起こすことがある。
If the flu worsens, it can cause pneumonia.
I get regular checkups to prevent my chronic condition from getting worse.