Haemoglobin: what your result means.

Haemoglobin is the oxygen-carrying protein in red blood cells and the defining measure of anaemia. It sits at the centre of energy, exercise capacity and cognitive performance.

Why Haemoglobin matters

Anaemia affects roughly a quarter of the world's population, iron deficiency being the leading cause, and in older adults even mild anaemia independently predicts hospitalisation and mortality. Low haemoglobin is always a finding to explain, not just correct: the cause (iron, B12, blood loss, chronic disease) is the diagnosis that matters.

Associated risks when out of range: Anaemia (low), Polycythaemia/dehydration (high).

What the clinical evidence shows

The evidence base behind how the HodieLabs Evidence-Based Clinical Library interprets Haemoglobin, from randomised trials, prospective cohorts and genetic (Mendelian randomisation) studies. Full citations in the reference list below.

• WHO global estimates: anaemia affects roughly a quarter of the world's population, with iron deficiency the leading cause, the most common nutritional disorder on earth, and routinely missed without testing.
• Cardiovascular Health Study (Zakai et al. Archives of Internal Medicine 2005): in community-dwelling older adults, even mild anaemia was independently associated with increased mortality over 11 years. Low haemoglobin is never 'just age'.
• Clinical principle (WHO / RCPA standards): sex-specific thresholds define anaemia, but the evidence-based rule is that a low haemoglobin is a finding to be explained, iron studies, B12, bleeding source, not merely corrected.

Evidence-based reference ranges

The HodieLabs Evidence-Based Clinical Library interprets Haemoglobin against published clinical authority standards, never arbitrary "optimal" ranges. Measured in g/L:

Clinical interpretation

• Haemoglobin can be falsely elevated with dehydration or at altitude. Interpret with haematocrit.
• Iron deficiency causes microcytic anaemia (low MCV), while B12/folate deficiency causes macrocytic (high MCV).
• Both extremes of haemoglobin carry risk. Very high values approach polycythaemia territory with increased viscosity, while low values indicate anaemia.

What improves it: the evidence-based levers

• Investigate iron/B12/folate if low
• Clinical review if persistently abnormal

Recommended testing frequency: Annual, as part of a comprehensive panel. Single markers are always interpreted in context.

How Haemoglobin testing works at HodieLabs

Haemoglobin is measured in every Health Blueprint at our Melbourne Preventative Health & Longevity Clinic, interpreted by a doctor against the guideline-cited ranges above and tracked over time through your HodieLabs membership.

References

1. World Health Organization. Haemoglobin concentrations for the diagnosis of anaemia and assessment of severity. WHO reference standards.
2. Zakai NA, et al. A prospective study of anemia status, hemoglobin concentration, and mortality in an elderly cohort (Cardiovascular Health Study). Arch Intern Med. 2005;165:2214–2220.
3. Royal College of Pathologists of Australasia. RCPA Manual: haemoglobin reference intervals.

This page is general information from the HodieLabs Evidence-Based Clinical Library, not medical advice. Speak with your GP about what testing and care is appropriate for you.