貧血(ひんけつ)

貧血(ひんけつ) covers two things that English separates. Sense 1 is anemia proper — a shortage of red blood cells, a diagnosable condition. Sense 2 is the everyday use: the swimming, faint feeling that comes on when you stand up too fast or stand still too long.

Formation: 貧(ひん) 'poor, lacking' + 血(けつ) 'blood' — literally 'poor blood.'

Which sense is meant is usually clear from the verb. 貧血(ひんけつ)になる 'to become anemic' describes the condition; 貧血(ひんけつ)を起(お)こす 'to have a dizzy spell' describes a single episode.

Collocations

• 貧血(ひんけつ)になる: to become anemic
• 貧血(ひんけつ)を起(お)こす: to have a dizzy spell
• 貧血(ひんけつ)ぎみ: a bit anemic, inclined to dizziness
• 鉄欠乏性(てつけつぼうせい)貧血(ひんけつ): iron-deficiency anemia

Medical note: strictly, 貧血(ひんけつ) means anemia. What people usually call 貧血(ひんけつ) in sense 2 is orthostatic hypotension, 起立性(きりつせい)低血圧(ていけつあつ) — a drop in 低血圧(ていけつあつ) on standing, which is a different thing. The loose usage is universal and no one will misunderstand you, but a doctor will make the distinction.