Hemoglobin (Hb)
Hemoglobin is the protein in red blood cells that carries oxygen. It is the main number used to check for anemia.
At a glance
- Sample
- Blood
- Units
- g/dL (US), g/L (Europe)
- Often looked at with
- MCHC, RDW
- Preparation
- No special preparation is usually needed. If other tests are done from the same sample, you may be asked to come fasting.
Units: g/dL and g/L
US and German labs usually print hemoglobin in g/dL, labs in the UK and much of Europe in g/L. Dutch labs print it in mmol/L: 1 g/dL is 0.6206 mmol/L. To convert, multiply g/dL by 10.
g/L = g/dL × 10
This converter changes units only. It doesn’t tell you whether a number is in or out of any range: that depends on the range printed by your own lab, and on your doctor. Soma does not diagnose and is not medical advice.
Why lab ranges differ
Each lab sets its reference range for its own method and analyser, and many ranges differ by age and sex. Two labs can print different ranges for the same blood, so a result is read against the range on its own report, not against a number from another lab or a website.
Soma charts every hemoglobin result against the range printed by the lab that measured it.
What can affect the result
- Too little fluid in the body before the test: raises the result.
- A lot of fluid from a drip: lowers it.
- Recent blood loss or blood donation.
If something like this applies, mention it to the doctor who reads your results.
Questions
How do I convert hemoglobin from g/dL to g/L?
Multiply g/dL by 10. For example, 13.5 g/dL is 135 g/L.
Why does my lab’s hemoglobin range differ from another lab’s?
Each lab sets its range for its own method and equipment, and many ranges differ by age and sex. That’s why a result is best read against the range printed on the same report.
How do I prepare for a hemoglobin test?
No special preparation is usually needed. If other tests are done from the same sample, you may be asked to come fasting. Follow your lab’s instructions.
Related tests
Got a lab report with Hemoglobin?
Share it to Soma: it reads every row on your phone, with no account and no upload, and puts your hemoglobin on one chart with your earlier results, each against the range your lab printed.
Sources
- Hemoglobin Test — MedlinePlus, U.S. National Library of Medicine.
- Units: 1 g/dL = 10 g/L by the metric prefixes, as the Soma app converts.
- Complete Blood Count (CBC) — MedlinePlus, U.S. National Library of Medicine.
Mention of a source doesn’t mean it endorses Soma. This page explains the test; it doesn’t diagnose and is not medical advice. Talk to your doctor about what your results mean.