Ferritin is normal, haemoglobin is normal, but I'm exhausted. Could inflammation be masking iron deficiency?
Hello! This will probably be a bit of a long one, so apologies in advance!
I’m 36F living in Scotland. Some potentially relevant medical context: I have multiple sclerosis (MS) and started an anti-CD20 medication called Kesimpta (ofatumumab) in May 2026. I understand this can affect B-cell levels, although I’m not sure how relevant it is to my current symptoms or blood results.
I was previously diagnosed with iron deficiency in November 2023 and took iron tablets for around three months. Since then, I’ve been taking a daily iron gummy containing 19 mg of iron.
Over the last few months, I’ve been experiencing increased tiredness and brain fog. I’ve also had intermittent heart flutters/palpitations since Boxing Day 2025. These come and go: sometimes I can go a long time without experiencing them, but I had a week in September when they were happening quite persistently. They’ve since settled down again.
I started wondering whether my iron levels might be low again, particularly as I’ve been eating less meat recently.
My GP arranged blood tests to investigate the tiredness, including iron/ferritin, B12, folate, vitamin D and thyroid function. I have attached pictures of the results, but the main findings were:
Haemoglobin: 129 g/L (reference range 115–165)
Ferritin: 115 ng/mL (reference range 14–186)
MCV: 81.6 fL (reference range 80–100)
MCH: 27.3 pg (reference range 27–32)
CRP: 18 mg/L (reference range below 6)
Lymphocytes: 0.8 × 10⁹/L (reference range 1.0–4.0)
B12: 986 pg/mL (high; I take a B12 supplement)
Folate: above 20 ng/mL
TSH: 2.01 and free T4: 14.4, both within range
The rest of my full blood count, kidney function, liver function, electrolytes and HbA1c were within the laboratory reference ranges.
My GP said the results were generally fine, apart from the raised CRP, and has asked me to repeat the blood test in two weeks.
I realise my haemoglobin and ferritin are both within the laboratory reference ranges, so I’m not assuming I have iron-deficiency anaemia. However, I’ve read that inflammation can raise ferritin, and my CRP is elevated. I also noticed that my MCV and MCH are towards the lower end of their reference ranges.
For additional context, I remember having raised CRP results of around 14–15 back in 2021/2022, when my MS was being investigated. I don’t know whether this is relevant or whether there could be an ongoing reason for the inflammation.
I’m particularly interested in whether iron deficiency without anaemia, or iron deficiency that might be harder to identify because of inflammation, is something worth discussing with my GP. Would tests such as transferrin saturation or other iron studies provide any additional useful information in this situation?
I’m also trying to work out what might be contributing to the fatigue and brain fog, given that most of my blood results are reassuring. I appreciate that MS and my medication could potentially be relevant, but I don’t want to assume they’re the cause.
Has anyone had a similar experience, particularly with a normal-range ferritin alongside an elevated CRP? I’d be grateful to hear about your experiences or anything you think would be worth discussing with my GP.
Thank you for reading this far!