Alternative Therapies, Wellbeing
Feeling exhausted despite “normal” blood tests? Low ferritin can cause fatigue, brain fog, hair shedding and poor exercise tolerance before anaemia appears.
It is one of the most common conversations I have in clinic.
A woman arrives exhausted, genuinely, deeply tired, having been told that her blood tests are “normal”. Her iron is fine. She is not anaemic. There is nothing to worry about.
And yet she is struggling to get through the day. Her hair is coming out in the shower. She cannot concentrate. She wakes unrefreshed despite sleeping for eight hours. She wonders whether it is menopause, depression, stress, or simply that she is not coping.
Very often, the answer is sitting there in the blood results but it has been missed.
The problem is usually ferritin.
What Is Ferritin?
Ferritin is the protein your body uses to store iron. Think of it as your iron warehouse.
Iron is needed for red blood cell production, energy, thyroid function, hair growth, muscle performance, and brain function. When ferritin is low, your body’s iron stores are depleted, even if your haemoglobin is still normal.
This is called iron deficiency without anaemia. It is well recognised clinically, but it is still commonly missed because many routine blood tests focus on haemoglobin rather than iron stores. Ferritin below 30 µg/L is widely recognised as confirming iron deficiency, but symptoms may occur before anaemia develops.
Ferritin is the warehouse, not the product. You can be iron deficient long before you become anaemic.
Why “Normal” Does Not Always Mean Optimal
Most laboratories only flag ferritin as low when it falls below around 12–15 µg/L. By that point, iron stores are severely depleted.
Many women are told their result is normal when their ferritin is 20, 30 or 40 µg/L. Technically, it may sit within the laboratory reference range, but clinically, it may not be enough for that woman to feel well.
Symptoms linked with low iron stores can include fatigue, poor concentration, reduced exercise tolerance, restless legs, hair shedding, dizziness, low mood, and reduced quality of life.
Why Women Are Particularly Vulnerable
Women are at higher risk of iron deficiency for several reasons:
Periods and heavy bleeding: Monthly blood loss is one of the most common causes of iron depletion. Heavy, prolonged or erratic periods in perimenopause can rapidly reduce iron stores.
Pregnancy and postnatal depletion: Iron requirements rise significantly during pregnancy and breastfeeding, and many women never fully rebuild their stores afterwards.
Plant-based diets: Iron from plant sources is less easily absorbed than haem iron from animal sources, so women following vegetarian or vegan diets may need closer monitoring.
Gut absorption issues: Coeliac disease, inflammatory bowel disease, gut surgery and some digestive conditions can reduce iron absorption.
Inflammation: Ferritin rises during inflammation because it is an acute-phase reactant. This means ferritin can look falsely reassuring if CRP is raised, which is why ferritin should be interpreted alongside inflammatory markers.
The Symptoms Nobody Joins Up
Iron deficiency symptoms often overlap with menopause, thyroid problems, depression, burnout and poor sleep.
Common symptoms include:
Extreme fatigue
Brain fog
Hair shedding or thinning
Poor concentration
Low mood
Breathlessness on exertion
Palpitations
Dizziness
Restless legs
Reduced exercise tolerance
Feeling cold
Waking unrefreshed
In midlife women, it is very easy for these symptoms to be blamed entirely on hormones. Sometimes hormones are part of the picture, but they are not always the whole story.
Understanding Ferritin Levels
Ferritin Level | What It May Suggest | How It May Feel |
Below 15 µg/L | Severely depleted iron stores | Profound fatigue, dizziness, breathlessness, palpitations |
15–30 µg/L | Iron deficiency without anaemia | Fatigue, brain fog, poor exercise tolerance, hair shedding |
30–50 µg/L | Low or suboptimal for some women | Persistent tiredness, low mood, reduced concentration |
50–70 µg/L | Low-normal | Some women may still be symptomatic |
70–100 µg/L | Often a useful clinical target range | Improved energy, clarity, hair health and resilience |
Above 100 µg/L | Needs interpretation | May reflect adequate stores, inflammation or iron overload |
Ferritin above 100 µg/L does not always mean iron overload. If inflammation is present, ferritin may be raised while functional iron deficiency still exists. Transferrin saturation below 20% can support a diagnosis of iron deficiency, particularly when inflammation complicates interpretation.
What a Proper Iron Assessment Should Include
A thorough assessment should not rely on ferritin alone. It should usually include:
Ferritin: The key marker of stored iron.
Full Blood Count: Checks haemoglobin, red cell size and whether anaemia is present.
Serum Iron, TIBC and Transferrin Saturation: Helps assess how much iron is available for use.
CRP: Checks inflammation, which can falsely raise ferritin.
B12 and Folate: Deficiencies can cause similar symptoms, including fatigue and brain fog.
Thyroid Function: Thyroid problems are common in midlife women and can mimic iron deficiency.
Vitamin D: Low vitamin D can worsen fatigue, low mood and musculoskeletal symptoms.
Treating fatigue without checking the full picture is like fixing one flat tyre on a car with three more punctures.
Being told your iron is “normal” does not always mean your iron stores are healthy.
If you are exhausted, losing hair, struggling with brain fog, feeling low, or finding exercise harder than usual, ferritin should be checked and interpreted properly, alongside inflammation, thyroid function, B12, folate and vitamin D.
For many women, especially in perimenopause and menopause, the issue is not that nothing is wrong.
It is that nobody has looked closely enough.
Take control of your health with fast, professional, and confidential results, book your advanced iron blood test today. Book here