Haemoglobin

Looks like

An iron-containing protein packed into red blood cells, about 270 million molecules in each, which makes blood red.

What it does

Picks up oxygen in the lungs and releases it in the tissues.

Keeping it well

Low levels (anaemia) cause tiredness and breathlessness; iron loss from heavy periods is a common cause. Carbon monoxide binds it and kills — fit an alarm.

Related conditions

• African trypanosomiasis (sleeping sickness)
• Anaemia
• Aplastic anaemia & marrow failure
• Clotting disorders (thrombophilia & APS)
• Dehydration & electrolyte disorders
• Delirium
• Dengue & mosquito-borne fevers
• Diabetic ketoacidosis
• Disseminated intravascular coagulation
• Ebola virus disease
• G6PD deficiency (favism)
• Haemophilia & bleeding disorders
• Hereditary spherocytosis
• High cholesterol
• Malnutrition & refeeding syndrome
• Maternal (puerperal) sepsis
• MRSA and resistant staph infection
• Myelodysplastic syndromes
• Neonatal sepsis
• Neutropenic sepsis
• Postpartum haemorrhage
• Scrub typhus & rickettsial infections
• Sepsis
• Shock (circulatory failure)
• Sickle cell disease
• Thalassaemia
• Toxic shock syndrome
• Typhoid & cholera
• Vitamin B1, C and other deficiencies
• Vitamin D deficiency
• Von Willebrand disease