Haemoglobin

What it is

Haemoglobin is a protein found inside your red blood cells. Its main job is to pick up oxygen from your lungs and carry it around your body to all your tissues and organs. It also helps to carry carbon dioxide, a waste product, back to your lungs to be breathed out. Think of it as a tiny delivery service within your bloodstream, ensuring every part of your body gets the oxygen it needs to function.

The amount of haemoglobin in your blood is measured in grams per litre (g/l). For adult men, the typical range is usually between 130–180 g/l, and for adult women, it's generally between 120–160 g/l, though these ranges can vary slightly between different laboratories.

Why it matters

The level of haemoglobin in your blood is a key indicator of your overall health. If your haemoglobin levels are too low, it means your red blood cells might not be carrying enough oxygen to your body. This can lead to a feeling of tiredness and weakness, a condition known as anaemia.

Conversely, if your haemoglobin levels are too high, it can mean your blood is thicker than usual, which can sometimes make it harder for it to flow smoothly. Monitoring haemoglobin levels helps doctors understand how well your body is functioning and can be a signpost for various health conditions.

What can cause it to be high or low

Low Haemoglobin (Anaemia)

A common reason for low haemoglobin is anaemia. There are many types of anaemia, and they can be caused by different things:

• Iron Deficiency: This is the most frequent cause. Your body needs iron to make haemoglobin. If you don't have enough iron, you can't produce enough haemoglobin. This can happen due to not eating enough iron-rich foods, or due to blood loss (for example, heavy periods in women, or bleeding in the digestive system).
• Vitamin Deficiencies: Lack of certain vitamins, like vitamin B12 and folate, can also affect red blood cell production and therefore haemoglobin levels.
• Chronic Diseases: Long-term illnesses, such as kidney disease, cancer, or inflammatory conditions (like rheumatoid arthritis), can sometimes interfere with your body's ability to make red blood cells.
• Blood Loss: Significant blood loss from injury, surgery, or conditions like stomach ulcers or bowel polyps can lower haemoglobin levels.
• Red Blood Cell Destruction: In some cases, red blood cells are destroyed faster than they can be made. This can be due to inherited conditions like sickle cell anaemia or thalassaemia, or sometimes due to certain medications or infections.

High Haemoglobin

Having a haemoglobin level that is higher than the normal range is less common than having low levels. It can be associated with:

• Dehydration: When you're dehydrated, the fluid in your blood decreases, making the concentration of red blood cells and haemoglobin higher.
• Lung Disease: Conditions that affect your lungs' ability to take in oxygen, like COPD (Chronic Obstructive Pulmonary Disease), can sometimes cause your body to produce more red blood cells to compensate.
• Certain Cancers: Some types of cancer can lead to an increase in red blood cell production.
• Bone Marrow Disorders: Conditions affecting the bone marrow, where red blood cells are made, can sometimes result in overproduction.
• Living at High Altitudes: People who live at high altitudes often have higher haemoglobin levels because there is less oxygen in the air, so their bodies produce more red blood cells to capture what oxygen is available.
• Smoking: Smoking can lead to higher haemoglobin levels.

Lifestyle factors that may help

If your haemoglobin levels are low due to iron deficiency, focusing on your diet can be helpful. Discussing with your GP about incorporating more iron-rich foods into your meals might be beneficial. Foods like lean red meat, poultry, fish, beans, lentils, and dark leafy greens are good sources of iron. Vitamin C also helps your body absorb iron, so pairing iron-rich foods with fruits and vegetables high in Vitamin C, such as oranges, strawberries, and bell peppers, could be a good strategy.

For those whose haemoglobin levels might be affected by lifestyle choices, such as smoking, making changes in this area could be discussed with your GP. Maintaining good hydration is also important for overall blood health.

Questions to discuss with your GP

• What is my haemoglobin level, and how does it compare to the normal range?
• What are the possible reasons for my haemoglobin level being outside the normal range?
• Are there any specific dietary changes you would recommend for me?
• Could my current medications or any underlying health conditions be affecting my haemoglobin?
• What further tests might be needed to understand my haemoglobin level?
• What signs or symptoms should I watch out for that might indicate a change in my haemoglobin?