What ferritin is
Ferritin is the protein that stores iron, and the small amount in the blood reflects how much iron you have in reserve. When stores fall, ferritin falls first. Haemoglobin, the measure of anaemia, usually drops only later, so low ferritin is an early warning.
What counts as low
Laboratory ranges vary, but a ferritin below about 30 micrograms per litre is generally taken as a sign of iron deficiency in adults. Values between 30 and 50 can still be low for someone with symptoms. Your report shows the range the laboratory uses.
Common symptoms
Tiredness and low energy, poor concentration, breathlessness on stairs or exercise, hair shedding, brittle nails, restless legs and feeling cold. Some people have no symptoms at all.
Common causes
Heavy periods, pregnancy and breastfeeding, a diet low in iron or a plant-based diet without planning, frequent blood donation, endurance sport, and conditions that reduce absorption such as coeliac disease. Blood loss from the gut is an important cause that has no obvious symptoms.
When to see a GP
Low iron without a clear reason should always be investigated, particularly in men and in women after the menopause, because it can be the first sign of bleeding from the gut. See your GP promptly if low ferritin comes with a change in bowel habit, blood in your stool, weight loss or indigestion.
A high ferritin does not always mean high iron
Ferritin also rises with inflammation, infection, liver problems and alcohol, so a normal or high result can hide low iron in someone who is unwell. That is why ferritin is read alongside iron, transferrin saturation and CRP.
At Omnia
Ferritin with full iron studies is included in Omnia Essential Plus (£109), Tired All The Time (£165), Sports Performance and the Randox Everyman and Randox Everywoman. We explain your result, and if it points to a GP referral, we give you the report to take with you. See every test and price.