吐血

1. Origins, structure, and basic meaning

• Structure: 吐血(とけつ) is the medical term for vomiting blood, or hematemesis.
• Basic usage: It is used when a person suddenly vomits blood or when describing a symptom requiring emergency attention. Typical patterns are 突然吐血する and 吐血が見られる.

2. Common pitfalls and similar expressions

• Connect the noun and verb uses
  • The symptom is named 吐血, and the form 吐血する states that someone vomits blood.
• Difference from 血を吐く
  • 血を吐く is the plain expression “vomit blood,” while 吐血 is the concise medical noun for the same event.