Low ferritin in women: what the new iron deficiency guidance means
If you have been told your iron levels are normal while still feeling exhausted, it can be difficult to know what to make of the result. New guidance from the American Society of Hematology brings attention to a distinction that can get lost in that conversation: iron deficiency can exist before you become anaemic, and a ferritin result needs to be understood alongside your symptoms and health history.
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What's changed
In September 2026, the American Society of Hematology published new guidance on diagnosing iron deficiency, with or without anaemia. Its recommended ferritin thresholds include 30 micrograms/L or below for adults, including menstruating and pregnant individuals, and 50 micrograms/L or below for certain higher risk groups, including people with heavy menstrual bleeding and pregnant individuals with anaemia. These are diagnostic thresholds for particular groups, rather than targets everyone should aim to reach.
For those of us in the UK, the adult threshold of 30 is not a new discovery. UK clinical guidance already recognises ferritin below 30 micrograms/L as indicating low iron stores, while below 15 indicates absent stores. However, in clinic here at Urban Wellness, we often see clients whose low iron stores have gone unrecognised or untreated, even though ferritin should be interpreted alongside their symptoms and the wider clinical picture. The hope is that the US update strengthens the emphasis on recognising deficiency, so that fewer people are left living with depleted iron stores.
Iron deficiency and anaemia are different
When we talk about low iron, it is easy to assume that being iron deficient and being anaemic mean the same thing, although they describe different stages of what can happen when your body does not have enough iron. Your body keeps some iron in reserve, rather like a supply cupboard that it can draw on when needed, and ferritin gives us an idea of how much is left in that cupboard. Haemoglobin is the protein in your red blood cells that carries oxygen around your body, and you need iron to make it.
If you are losing more iron than you are taking in or absorbing, your body can draw on those reserves to keep making haemoglobin, so your stores may be running low while your haemoglobin result still looks normal. If the shortage continues, haemoglobin can eventually fall too, which is when iron deficiency has progressed to iron deficiency anaemia. This means that being told you are not anaemic can be reassuring, but it does not necessarily mean you have enough iron in reserve, which is why we need to look at ferritin as well as haemoglobin.
Low iron can be associated with tiredness, difficulty concentrating, dizziness, hair loss and restless legs, although these symptoms have other possible causes too. If they sound familiar, the useful next step is a clinical review rather than assuming that iron explains everything, or dismissing the symptoms because one result looks reassuring.
Why symptoms and context matter
A laboratory reference range and a diagnostic threshold serve different purposes, which is why the printed range cannot provide the whole answer. Your GP should consider ferritin alongside your full blood count, symptoms, menstrual history, diet, medicines and possible blood loss, with further tests where needed.
Inflammation adds another complication because it can raise ferritin, masking iron deficiency. Transferrin saturation, which helps assess circulating iron availability, and inflammatory markers can be useful when the ferritin result is difficult to interpret. A normal or raised ferritin therefore needs context too.
These cut-offs help clinicians recognise when iron stores are low, although they do not tell us exactly where everyone’s ferritin should end up after treatment. For example, a threshold of 30 does not mean that getting your result just above 30 will necessarily replenish your iron stores or resolve your symptoms. This is why we take a functional medicine approach at Urban Wellness, looking at your blood results alongside your symptoms and health history, rather than treating a number in isolation. If your iron stores are low, we also want to understand what caused the deficiency and how you are responding to treatment, so that any decision about further iron takes the whole picture into account.
Low ferritin after menopause
Low ferritin turns up again and again in women over 50 in our clinic, often well past the point where periods could explain it. The usual assumption is that once bleeding stops, iron deficiency should resolve itself, but for a lot of women it doesn't.
During perimenopause, heavier periods can increase iron loss, so changes in bleeding are an important part of the conversation. Once periods have stopped, unexplained iron deficiency still needs medical assessment, particularly if anaemia is also present, because menstrual loss can no longer explain it. Possible causes include low intake, reduced absorption and gastrointestinal blood loss.
One pattern we see repeatedly is a history of chronic stress or earlier trauma sitting alongside stubbornly low ferritin. That's not a coincidence, as long-term stress keeps inflammatory signalling switched on, and that raises a hormone called hepcidin, the master regulator of how much iron your gut actually lets through. When hepcidin stays high, your body holds iron back in storage rather than making it available, so ferritin can stay low even with a reasonable diet and consistent supplementation.
This is exactly why we don't treat low ferritin as a simple "eat more iron" problem in postmenopausal women, particularly where stress or trauma has been part of the picture. The full story is often about what's driving the inflammation, not just what's on the plate.
What to do with your result
If your ferritin was previously between 15 and 30 micrograms/L and you were told it was normal, ask your GP to review it alongside your symptoms and the rest of your blood results. You can ask whether you have iron deficiency without anaemia, what might be contributing to it and whether further testing or treatment would be appropriate.
Where treatment is needed, replacing iron and understanding the cause can happen together, with follow-up blood tests to check the response. Iron tablets can often cause side effects, such as constipation, which is why we always recommend iron bisglycinate as it is a lot gentler on digestion.
At Urban Wellness, we look at blood results alongside how you are feeling, your health history and your nutrition, helping you make sense of the wider picture and identify questions to take to your GP. If you have been told your results are normal but still feel depleted, get in touch and we can explore that picture together.
More on iron and ferritin
This post is part of a wider series on iron in midlife. You might also want to read:
