What else could be behind your perimenopause symptoms?
Registered Nutritionist Limerick, Cork and ONLINE Nutritionist Claire Russell MSc. BSc. DipNT MNTOI MICIP – an Evidence-based guide for women in Ireland — with practical next steps and testing options
Fatigue. Anxiety. Brain fog. Heavy periods. Broken sleep. Weight. More body fat, less energy. Does this sound Familiar? These symptoms are commonly felt and discussed during the perimenopause transition — yet fluctuating hormones are not the only possible cause. The same symptoms can be driven by iron deficiency, thyroid dysfunction, and insulin resistance. When symptoms overlap, it’s easy to assume “this is just perimenopause” and adopt this as a new normal. However our Bodies rarely speak in absolutes; they speak in signals. If we take the time to listen and Read those signals correctly, then the path to relief becomes clearer. (NICE)
The overlap problem, and why it matters
When a symptom resolves after correcting a non-hormonal driver (for example, restoring iron stores), then hormones were not the primary cause of that symptom. That distinction matters, because treating the driver (not just the label) is key to how to get lasting results. NICE guidance supports assessing the wider picture — not only menopause care, but also heavy menstrual bleeding, anaemia, thyroid function, and metabolic risk. (NICE)
One glance comparison: common symptoms and likely contributors
| Symptom | Perimenopause (oestrogen/progesterone shifts) | Iron deficiency / IDA | Thyroid dysfunction | Insulin resistance / blood sugar dysregulation |
|---|---|---|---|---|
| Fatigue | Very common | Very common | Very common (especially hypo) | Common |
| Anxiety / palpitations | Common | Reported in ID/IDA studies | Common (hyper > hypo) | Can fluctuate with dysglycaemia |
| Brain fog / poor concentration | Common | Reported (attention, processing speed) | Common (hypo) | Common with glycaemic variability |
| Heavy, frequent, or flooding periods | Can occur early in transition | Consequence → worsens ID | Classic in hypothyroidism | Indirect |
| Poor sleep / night sweats | Very common (vasomotor) | Possible (restlessness) | Common | Common (esp. nocturnal dysglycaemia) |
| Weight gain / central adiposity | Body fat redistribution at midlife | — | Possible (hypo) | Key feature |
Evidence snapshots: NICE recommends HRT as first-line for troublesome vasomotor symptoms; the Heavy Menstrual Bleeding guideline emphasises assessing anaemia; hypothyroidism is linked with menstrual irregularities; the menopause transition is associated with increasing central adiposity and metabolic risk. (NICE, Nature)
Three of the most frequently missed drivers
1) Iron deficiency, with or without anaemia
Why it matters: Low iron impairs oxygen transport and neurotransmitter synthesis, and is associated with fatigue, cognitive changes, and mood symptoms. Ferritin, your iron stores, is the key biomarker; in inflammation this can often look “normal,” so the context and additional indices (e.g., transferrin saturation) really matter. (Iris, World Health Organization, BSH)
Clues: Heavy periods, both presently and / or historically, flooding, very frequent cycles, long-term dieting or under-eating, low- or no-meat diets, little or not red meat, endurance training, and pregnancy history all raise risk. A Full Blood Count is advisable in situations of history of heavy menstrual bleeding, specialist guidelines outline when to check ferritin and transferrin saturation. (NICE, BSH)
Cognition & mood: Reviews and also meta-analyses link iron deficiency/ anaemia with impaired attention and processing speed and with higher odds of cognitive impairment; Several studies report associations with anxiety-spectrum symptoms. Correction of iron status improves performance in iron-deficient women. (PMC, BioMed Central, ScienceDirect)
Nutrition note for practical guidance: Vitamin C enhances non-haem iron absorption; tea/coffee and polyphenol-rich beverages markedly reduce it when consumed with meals. Separating these drinks from iron-rich meals or supplements can make a tangible difference. (NCBI, Cambridge University Press & Assessment, PMC)
2) Thyroid dysfunction: both hypothyroidism or hyperthyroidism
Why it matters: Thyroid hormones regulate metabolism, temperature, mood, menstruation, and cognition. Hypothyroidism commonly presents with fatigue, weight gain, cold intolerance, and can increase menstrual bleeding; hyperthyroidism can drive anxiety, palpitations, sleep disruption, and weight loss. NICE provides clear testing and management recommendations. (NICE)
Clues: Marked changes in cycle heaviness, persistent fatigue unresponsive to sleep / nutrition changes, constipation / low mood (hypo) or tremor / heat intolerance (hyper). Evidence links hypothyroidism with heavy or irregular bleeding patterns. (PMC, ScienceDirect)
What to test: TSH as first-line; follow with free T4 (± free T3) and thyroid antibodies where indicated — and treat per guideline thresholds. (NICE)
3) Insulin resistance and midlife metabolic change
Why it matters: During the menopause transition, body fat distribution shifts towards the abdomen and insulin sensitivity can decline — even without major weight change — increasing risk for dysglycaemia and type 2 diabetes. (Nature)
Clues: Increasing waist circumference, mid-afternoon energy crashes, carbohydrate cravings, family history of type 2 diabetes, gestational diabetes history, and poor sleep. Longitudinal studies and reviews (including SWAN and EMAS guidance) show central adiposity and insulin resistance rise around this life stage. (swanstudy.org, ScienceDirect)
What to test: Fasting glucose, HbA1c the diagnostic threshold ≥6.5%, and in the right context only fasting insulin or an OGTT. Use your GP’s diagnostic criteria and retest/confirm abnormal findings. (Diabetes Journals, Iris)
When hormones are the primary driver
Hormone therapy (HRT/MHT) is the most effective intervention for vasomotor symptoms : hot flushes/night sweats, and often improves sleep and quality of life. NICE recommends offering HRT for troublesome vasomotor symptoms, and also supports menopause-specific CBT as an option, either as an adjunct or where HRT isn’t appropriate or preferred. (NICE)
There is also credible evidence that clinical hypnosis can reduce vasomotor symptom burden in appropriate candidates — including RCTs in both postmenopausal women and breast cancer survivors. This can be integrated alongside nutrition and psychological strategies. (PMC)
A precise, step-by-step way to investigate your symptoms
- History & pattern mapping
Track symptoms (timing, triggers, cycle relation), bleeding volume/frequency, sleep, energy dips, and foods/caffeine near meals or supplements. (This often reveals iron-related patterns and glycaemic swings.) - Core laboratory checks (via your GP or consultant):
- Full Blood Count; serum ferritin (consider transferrin saturation if inflammation is possible). Treat iron deficiency/anaemia per guideline. (NICE, BSH)
- TSH → reflex free T4 (± free T3) and TPO antibodies if indicated. Manage per NICE NG145. (NICE)
- HbA1c (diagnosis ≥6.5%); consider fasting glucose ± OGTT in borderline or discordant cases. (Diabetes Journals, Iris)
- If vasomotor symptoms are dominant and investigations are otherwise unrevealing, discuss HRT (benefits, risks, and route) with your prescriber, aligned with NICE NG23. (NICE)
- Nutrition & daily-life adjustments while you wait for results:
- Pair non-haem iron foods with vitamin C-rich foods; leave tea/coffee 60–120 minutes away from iron-rich meals or supplements. (NCBI, Cambridge University Press & Assessment)
- Structure meals to reduce glycaemic swings (protein and fibre anchors; evenly spaced meals).
- Prioritise consistent sleep–wake times; address night-time hot flushes via evidence-based therapies (HRT where suitable, CBT strategies, clinical hypnosis). (NICE, The Lancet, PMC)
How my integrated clinical approach helps ONLINE across Ireland, and in-person in Adare, Newcastle West Limerick, Abbeyfeale, Midleton, Youghal, Cork & Dungarven
As a Registered Nutritionist, Clinical Medical Hypnotherapist, Clinical Hypnotherapist, Psychotherapist/Counsellor, and Advanced RTT-qualified practitioner, I work at the intersection of biochemistry, behaviour, and nervous-system regulation to address the real drivers of your symptoms — not just the surface label.
- Thorough assessment: I review your symptom map, bleeding history, dietary pattern, sleep, stressors, and medications/supplements, then advise targeted labs in line with your GP, NICE and specialty guidelines. (NICE)
- Evidence-based nutrition: Iron-replete menu design, absorption strategy (what to pair/what to separate), and metabolic meal structuring tailored to your preferences (including low- or no-meat diets if you choose). (NCBI, Cambridge University Press & Assessment)
- Targeted therapeutics: Collaboration with your GP/consultant, contact your GP for HRT discussions where appropriate; We can offer non-pharmacological supports including menopause-specific CBT strategies with Counselling, Psychotherapy and clinical medical hypnosis for vasomotor symptoms, anxiety and sleep. (NICE, The Lancet, PMC)
- Measurable outcomes: We track symptoms and biomarkers so you can see progress — for example, ferritin repletion with symptom improvement, stabilised sleep, and reduced vasomotor episodes.
You do not have to accept feeling “not quite right.” When symptoms are treated as feedback, they become a roadmap. Whether your driver is iron, thyroid, insulin, hormones — or a combination — there is a structured path forward.
What to do next?
- If heavy or very frequent periods (or flooding) are part of your story, ask your GP for FBC + ferritin (and discuss treatment if low). (NICE)
- If anxiety, palpitations, or marked fatigue have escalated unexpectedly, include TSH (± free T4/T3) in your bloods. (NICE)
- If weight and waist are creeping up or you have energy crashes, add HbA1c (± fasting glucose). (Diabetes Journals)
- If vasomotor symptoms dominate, book a consultation to discuss HRT suitability and/or evidence-based psychological options (CBT, clinical hypnosis). (NICE, The Lancet, PMC)
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References:
- NICE. Menopause: identification and management (NG23). https://www.nice.org.uk/guidance/ng23
- NICE. NG23 Recommendations (Vasomotor, CBT, HRT). https://www.nice.org.uk/guidance/ng23/chapter/recommendations
- NICE. Heavy menstrual bleeding: assessment and management (NG88). https://www.nice.org.uk/guidance/ng88/chapter/recommendations
- NICE. NG88 Full Guideline (PDF). https://www.nice.org.uk/guidance/ng88/resources/heavy-menstrual-bleeding-assessment-and-management-pdf-1837701412549
- NICE. Thyroid disease: assessment and management (NG145). https://www.nice.org.uk/guidance/ng145
- NICE. NG145 Guideline (PDF). https://www.nice.org.uk/guidance/ng145/resources/thyroid-disease-assessment-and-management-pdf-66141781496773
- WHO. Guideline on use of ferritin concentrations to assess iron status (2020). https://www.who.int/publications/i/item/9789240000124
- British Society of Gastroenterology. Guidelines for the Management of Iron Deficiency Anaemia in Adults (2021) (PDF). https://gut.bmj.com/content/gutjnl/70/11/2030.full.pdf
- BSH. Good Practice Paper: Laboratory diagnosis of iron deficiency in adults (2021). https://b-s-h.org.uk/guidelines/guidelines/good-practice-paper-for-the-laboratory-diagnosis-of-iron-deficiency-in-adults-excluding-pregnancy-and-children
- Jáuregui-Lobera I. Iron deficiency and cognitive functions. Nutr Hosp. 2014. (PMC) https://pmc.ncbi.nlm.nih.gov/articles/PMC4235202/
- Kung WM et al. Anemia and risk of cognitive impairment: updated meta-analysis. Front Neurol. 2021. (PMC) https://pmc.ncbi.nlm.nih.gov/articles/PMC8231247/
- Pişkin E et al. Iron Absorption: Factors, Limitations, and Improvement Methods. ACS Omega. 2022. (PMC) https://pmc.ncbi.nlm.nih.gov/articles/PMC9219084/
- Hurrell RF et al. Inhibition of non-haem iron absorption by polyphenolic-containing beverages. Br J Nutr. 1999. (PDF) https://www.cambridge.org/core/services/aop-cambridge-core/content/view/5CFF5FF58F6CBA86D3646981A7DF0418/S0007114599000537a.pdf/inhibition-of-non-haem-iron-absorption-in-man-by-polyphenolic-containing-beverages.pdf
- StatPearls. Dietary Iron. Updated 2024. https://www.ncbi.nlm.nih.gov/books/NBK540969/
- Lee J et al. Coffee/green tea consumption and iron status (Pre-menopausal women). Nutrients. 2023. (PMC) https://pmc.ncbi.nlm.nih.gov/articles/PMC10040266/
- Lovejoy JC et al. Increased visceral fat with menopause: longitudinal study. Int J Obes. 2008. (PDF) https://www.nature.com/articles/ijo200825.pdf
- Nature Reviews Endocrinology. Interplay between diabetes mellitus and menopause (Review). 2022. (PDF) https://www.nature.com/articles/s41574-022-00708-0.pdf
- Diabetes Care (ADA). Diagnosis & Classification of Diabetes — Standards of Care 2025. https://diabetesjournals.org/care/article/48/Supplement_1/S27/157566/2-Diagnosis-and-Classification-of-Diabetes
- WHO. Use of HbA1c in the diagnosis of diabetes (policy brief). (PDF) https://iris.who.int/bitstream/handle/10665/70523/WHO_NMH_CHP_CPM_11.1_eng.pdf
- Diabetes Care. Longitudinal Changes in SHBG and Diabetes Risk across the Menopause Transition. 2024. https://diabetesjournals.org/care/article/47/4/676/154202/Longitudinal-Changes-in-Sex-Hormone-Binding
- Elkins GR et al. Randomized trial of a hypnosis intervention for hot flashes (breast cancer survivors). J Clin Oncol. 2008. (PMC) https://pmc.ncbi.nlm.nih.gov/articles/PMC2652097/
- Elkins GR et al. Clinical hypnosis for postmenopausal hot flashes: RCT. Menopause. 2013. (PMC) https://pmc.ncbi.nlm.nih.gov/articles/PMC3556367/
- British Menopause Society & Women’s Health Concern. Recommendations on HRT in menopausal women (2023 update) (PDF). https://thebms.org.uk/wp-content/uploads/2023/10/02-BMS-ConsensusStatement-BMS-WHC-2020-Recommendations-on-HRT-in-menopausal-women-SEPT2023-A.pdf
- NICE. NG23 PDF (Diagnosis & Management). https://www.nice.org.uk/guidance/ng23/resources/menopause-diagnosis-and-management-pdf-1837330217413
- NICE. Exceptional surveillance & evidence updates for NG23 (context on non-HRT options). https://www.nice.org.uk/guidance/ng23/resources/2021-exceptional-surveillance-of-menopause-diagnosis-and-management-nice-guideline-ng23-pdf-11992026533317
Professional Nutritionist note & safety guidance
This guide is educational and does not in any way replace individual medical advice. Always review personal results and treatment decisions with your GP, consultant, or prescribing clinician. The references above align with Irish and UK practice and current international standards where applicable.
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If you’d like a targeted assessment and plan that unpacks your symptom drivers — with a combined approach of nutrition, psychology, Clinical Medical Hypnotherapy / RTT, and if requested or required coordinated medical support. I offer ONLINE Nutrition and Medical Hypnotherapy appointments throughout Ireland and in-person Nutrition and Clinical Medical Hypnotherapy in Adare, Newcastle West Limerick, Abbeyfeale, Midleton, Youghal, Cork, and Dungarven.
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