Wellness . Symptoms guide
Iron Deficiency Symptoms and Testing
Quick answer
Iron deficiency is one of the most common nutritional deficiencies in the UK, particularly in women of reproductive age. Symptoms often appear before standard anaemia tests turn abnormal. Serum ferritin is the most sensitive marker of low iron stores, but because it is also an acute-phase reactant it can read falsely normal when inflammation or infection is present. A full iron study (ferritin, serum iron, total iron binding capacity, transferrin saturation) therefore gives a much clearer picture than ferritin or a full blood count alone.
This patient information is being clinically reviewed by our team. The factual content aligns with UK diagnostic frameworks, drawing on NHS primary care pathways, NICE clinical knowledge summaries on iron deficiency anaemia, and British Society for Haematology guidelines.
What this might be
- Dietary insufficiency. Especially in vegan or vegetarian patients.
- Heavy menstrual bleeding. Common in women of reproductive age.
- Increased demand. Pregnancy, breastfeeding, endurance training.
- Malabsorption. Coeliac disease, gastric surgery.
- Occult GI bleeding. Always considered in men and postmenopausal women.
When to seek urgent advice
If any of the following apply, please contact your GP or NHS 111 rather than waiting for private bloodwork.
- Black, tarry stools
- Visible blood in stool
- New or unexplained iron deficiency in any man or postmenopausal woman. In the UK, this is a high-priority clinical flag that mandates an urgent, fast-track NHS 2-Week Wait referral to investigate potential occult gastrointestinal blood loss. Do not delay this vital medical evaluation to wait for private test results.
Common features that suggest this
- Fatigue, especially with exertion
- Hair shedding
- Brittle nails
- Breathlessness on stairs
- Restless legs
- Pica (craving ice or unusual substances)
Recommended tests
Same-day appointments at our Harley Street clinic, results clinician-reviewed.
Need a marker not in these panels? Build a custom panel and a GMC-registered clinician will design one for you.
Markers your clinician will commonly look at
These are the individual blood markers in the recommended panels above. Click any to read what it measures, its UK reference range, and what high or low values mean.
Testing advice
No fasting. Avoid iron supplements for at least 24 hours before testing if you want a true baseline.
Common questions
What is a healthy ferritin level?
Current NICE CKS guidance uses below 30 micrograms per litre as the diagnostic threshold for iron deficiency (some laboratories still report below 15 as their lower limit). For hair shedding and fatigue, some clinicians prefer to see ferritin comfortably within range rather than at the lower end, but a single target value is not set by NICE. Full iron studies (ferritin plus serum iron, TIBC and transferrin saturation) and clinical context interpret the result better than ferritin alone.
Can I just take iron supplements?
Supplements help correct deficiency but do not address the cause. Persistent unexplained iron loss needs investigation, especially in men and postmenopausal women.
Related symptoms
Sources and further reading
This page provides general information only and is not a substitute for medical advice. A GMC-registered clinician will review your results and tailor any recommendations to you personally.