Typical reference ranges
| Group | Typical range | WHO anaemia cut-off |
|---|---|---|
| Adult men | 13.0–17.0 g/dL | Below 13.0 g/dL |
| Adult women (not pregnant) | 12.0–15.5 g/dL | Below 12.0 g/dL |
| Pregnancy, 1st and 3rd trimester | 11.0–14.0 g/dL | Below 11.0 g/dL |
| Pregnancy, 2nd trimester | 10.5–14.0 g/dL | Below 10.5 g/dL |
| Children 5–11 years | 11.5–15.5 g/dL | Below 11.5 g/dL |
Ranges based on: MedlinePlus; WHO; Mayo Clinic. Full references are listed at the end of this page.
Use your own lab's range. Reference ranges differ between labs, analysers and methods, and with age, sex and pregnancy. The range printed on your report takes priority over the figures here.
Check your value
Type the Hemoglobin result from your report to see where it sits against the typical ranges on this page. Nothing is sent or saved.
General information only, not a diagnosis. Your lab's printed range takes priority.
What low hemoglobin means
Low hemoglobin is called anaemia. It is very common, especially in women and children in South Asia and Africa. The most frequent causes are:
- Iron deficiency, from low dietary iron, heavy periods, pregnancy or slow bleeding from the gut
- Vitamin B12 or folate deficiency
- Long-term illness such as kidney disease or chronic infection
- Inherited conditions such as thalassaemia trait or sickle cell disease
- Recent blood loss
The red cell indices on the same report, especially MCV, help narrow the cause: small cells suggest iron deficiency or thalassaemia trait, large cells suggest B12 or folate deficiency.
What high hemoglobin means
A raised hemoglobin is less common. It can follow dehydration, smoking, living at high altitude, sleep apnoea or long-term lung disease, and testosterone treatment. Rarely it is caused by a bone marrow condition called polycythaemia vera.
Symptoms of anaemia
Tiredness, shortness of breath on exertion, pale skin, headaches, a fast heartbeat and feeling cold are common. Mild anaemia can cause no symptoms at all and is found on a routine test.
Units
Most labs report g/dL. UK and some Gulf labs use g/L, which is ten times larger: 12.5 g/dL is 125 g/L.
Frequently asked questions
What hemoglobin level is dangerous?
Levels below 7 g/dL usually need urgent assessment, and below 5 g/dL is life-threatening. Symptoms matter as much as the number.
What is a normal hemoglobin level for a woman?
About 12.0–15.5 g/dL outside pregnancy.
How can I raise low hemoglobin?
Treat the cause. Iron deficiency is treated with iron, but the reason for it must be found first. Talk to your doctor before starting supplements.
Is hemoglobin 11 low?
For a non-pregnant woman, yes, slightly. In pregnancy, 11 g/dL is at the WHO cut-off.
Sources and references
- MedlinePlus: Hemoglobin Test
- WHO: Guideline on haemoglobin cutoffs to define anaemia (2024)
- Mayo Clinic: Low hemoglobin count
- NHS: Iron deficiency anaemia
- Gloucestershire Hospitals NHS: Haematology reference ranges