Haemoglobin

Haemoglobin is the iron-rich protein packed inside your red blood cells that actually binds to oxygen and carries it from your lungs to the rest of your body. When we measure your haemoglobin level, we are checking how much of this vital protein is available to do that job, it is one of the most informative markers in a full blood count. Healthy haemoglobin levels are closely linked to how energetic and well you feel day to day. Because haemoglobin is the molecule doing the heavy lifting when it comes to oxygen delivery, even a modest drop can leave you feeling unusually tired, short of breath during activities that would normally feel easy, or a little lightheaded. On the other hand, levels that are comfortably within range generally mean your tissues are receiving all the oxygen they need to function at their best.

Picture each red blood cell as a tiny delivery van and haemoglobin as the cargo it carries. Each haemoglobin molecule can pick up four oxygen molecules in the lungs, transport them through the bloodstream, and release them precisely where they are needed, in your muscles during exercise, in your brain while you concentrate, or in your digestive system after a meal. On the return journey, haemoglobin collects carbon dioxide waste and ferries it back to the lungs to be breathed out. Iron is a key ingredient in this process, which is why your diet and iron stores have such a direct effect on your haemoglobin level.

The most common influences on haemoglobin include your iron intake, levels of vitamin B12 and folate, hydration status, and menstrual blood loss in those who have periods. Endurance athletes sometimes see lower readings due to a natural expansion of blood plasma volume, and altitude can push levels upward as the body adapts to thinner air. If your haemoglobin is outside the expected range, your GP can investigate further and advise on any simple steps, such as dietary adjustments or supplementation, that might help bring things back into balance.