# hemoglobin

/ˌhiməˈɡɫoʊbən/ (US) · CEFR C1 · Noun

Source: https://englishreference.com/word/hemoglobin
Updated: 2026-05-19

## Definition

a red protein in your blood that carries oxygen from your lungs to the rest of your body. It is what makes your blood look red.

For teachers: a complex iron-containing protein in red blood cells that binds oxygen and transports it through the bloodstream. It is responsible for the characteristic red colour of blood.

## Examples

- The doctor checked my hemoglobin levels to see if I was anemic.
- Low hemoglobin levels can lead to fatigue and shortness of breath because the body isn't getting enough oxygen.
- The structure of hemoglobin allows it to bind oxygen in the lungs and release it in the tissues, making it essential for cellular respiration.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.