What else could be behind your perimenopause symptoms?

Fatigue, anxiety, brain fog, heavy periods, poor sleep, weight gain, more body fat, less energy… These are widely recognised during the perimenopausal years. Oestrogen and progesterone fluctuations matter—but they’re not the only story. Many of the same symptoms can also be driven by iron deficiency, thyroid dysfunction, and insulin resistance / pre-diabetes. When signals overlap, it’s easy to assume “it’s just hormones” and put up with feeling sub-par. Your body isn’t speaking in absolutes; it’s sending signals. Interpreting those signals—carefully and scientifically—opens the door to specific, fixable causes and lasting relief. (HSE.ie)

Symptoms overlap

Below is a high-level map of how commonly reported symptoms cluster across perimenopause and three highly prevalent, often-missed drivers. A tick (✓) indicates the symptom is typically reported; a star (★) flags symptoms that strongly warrant testing for that condition as well.

Symptom Perimenopause Iron deficiency (± anaemia) Thyroid dysfunction Insulin resistance / pre-diabetes
Fatigue ✓ ✓★ ✓★ ✓
Anxiety / low mood ✓ ✓ ✓ ✓
Brain fog / poor focus ✓ ✓ ✓ ✓
Heavy or frequent periods ✓★ ✓★
Sleep disturbance ✓ ✓ ✓ ✓
Palpitations ✓ ✓ ✓★
Heat or cold intolerance ✓ (hot flushes) ✓ (hot/overactive; cold/underactive)★
Weight gain / increased central adiposity ✓ ✓ (underactive) ✓★
Acanthosis nigricans (velvety dark skin in folds) ✓★

Why the table matters: if fatigue, brain fog and palpitations improve after correcting iron deficiency, that wasn’t “just perimenopause”—it was iron deficiency present during perimenopause. Likewise, thyroid and glucose issues are common in midlife and can magnify symptoms attributed to the transition. (NICE, PMC, nhs.uk, HSE.ie)

How to tell what’s really driving your symptoms

Start with checking patterns and your history

  • Bleeding pattern: very heavy bleeding, flooding, clots or frequent periods increases the likelihood of iron deficiency. Addressing heavy menstrual bleeding is a medical priority in its own right. (NICE)
  • Cycle change + vasomotor symptoms (hot flushes/night sweats): point strongly to perimenopause; diagnosis is largely clinical (based on symptoms and age), not a single blood result—especially if you’re over 45. (NICE)
  • Skin clues: dark, velvety patches at the neck, armpits or groin (acanthosis nigricans) raise suspicion for insulin resistance. (nhs.uk, CDC)

Targeted testing, evidence-based and focused approach

Iron status

  • Full blood count, ferritin, transferrin saturation (TSAT). Ferritin <30 µg/L is supportive of iron deficiency in many settings; higher cut-offs apply with inflammation. Treating iron deficiency with or without anaemia is recommended because symptoms can be substantial. (PMC)

Thyroid function

  • TSH with reflex free T4 (± free T3 if indicated) and thyroid antibodies where appropriate. To follow NICE guidance for thresholds, treatment and monitoring. Symptoms of underactive thyroid (tiredness, weight gain, feeling cold) and overactive thyroid (anxiety, heat intolerance, palpitations, poor sleep) substantially overlap with perimenopause. (NICE, nhs.uk)

Glucose metabolism

  • HbA1c and/or fasting plasma glucose; oral glucose tolerance test (OGTT) in selected cases. In Ireland, HSE classifies pre-diabetes as HbA1c 42–47 mmol/mol; ADA additionally defines impaired fasting glucose at 5.6–6.9 mmol/L (100–125 mg/dL). (HSE.ie, American Diabetes Association)

Hormones for perimenopause?

  • Routine serum hormone testing to “diagnose perimenopause” is not usually indicated in women over 45 because levels are highly variable; clinical assessment is generally preferred. Testing therefore may be useful in specific situations (younger age, atypical symptoms, contraception masking cycles, POI suspicion). (NICE, The BMS)

Practical pathway you can use now

  1. Document symptom timeline + menstrual pattern,  include heaviness / flooding, cycle length, missed cycles.
  2. Screen for red flags (please see below).
  3. Test iron, thyroid, and glucose first when symptoms overlap, fatigue, anxiety, brain fog, palpitations, weight change, then we tailor next steps based on results.
  4. Tackle drivers in parallel: e.g., manage heavy bleeding (to reduce further iron loss), optimise your iron stores, treat thyroid disease per guideline, and improve insulin sensitivity with nutrition, strength training and sleep strategies. (NICE, PMC)

Effective, evidence-based care with Claire Russell Registered Nutritionist & Medical Hypnotherapy Limerick Cork and ONLINE

I combine Registered Nutritionist Services (to correct deficiencies and stabilise glucose), Counselling & Psychotherapy (to reduce anxiety, improve sleep and coping), Clinical Hypnotherapy / Clinical Medical Hypnotherapy and Advanced RTT (to reduce vasomotor symptom burden and stress-reactivity), plus a functional medicine approach to testing and root-cause planning. Randomised controlled trials show clinical hypnosis can meaningfully reduce hot flush frequency and severity and improve sleep and mood; Counsellling, Psychotherapy with CBT approaches also reduce the impact of vasomotor symptoms—useful whether or not you choose HRT. (PMC)

I provide ONLINE consultations nationwide and in-person support in Adare, Newcastle West Limerick, Abbeyfeale, Midleton, Youghal, Cork and Dungarven. Care is coordinated with your GP/consultant as needed,  for example  for HRT discussion or investigations for heavy bleeding etc.

Red flags —please get prompt medical assessment if you are experiencing:

  • Very heavy bleeding, flooding or bleeding that causes dizziness, shortness of breath, or iron deficiency—assessment and management are recommended. (NICE)
  • Post-menopausal bleeding (any bleeding ≥12 months after your final period). (HSE.ie)
  • Palpitations with chest pain, fainting, or breathlessness, or new rapidly worsening anxiety/tremor/heat intolerance (possible thyroid overactivity). (nhs.uk)

Targeted Actions:

If heavy periods feature:

  • Ask your GP about treatment options to reduce blood loss and test iron stores; dietary iron plus appropriate supplementation should be timed away from tea/coffee and taken with food; vitamin C–rich foods can aid non-haem iron absorption. (NICE, HSE.ie, nhs.uk)

If fatigue/brain fog dominate:

  • Check iron, thyroid and glucose; each can independently cause fatigue and cognitive difficulties. Correcting the driver often improves symptoms significantly. (PMC, NICE)

If weight gain and energy dips are new:

  • Midlife is associated with unfavourable body-composition shifts (more fat, less lean mass) around the final menstrual period; resistance training and protein-forward meals support metabolic health. (PMC)

If flushes and sleep disruption persist:

  • Discuss HRT appropriateness with your GP (it remains the most effective option for vasomotor symptoms); non-hormone options exist. Behavioural therapies—including structured hypnotherapy protocols and CBT—have peer-reviewed evidence for reducing symptom burden. (The Menopause Society, PMC)

Book a Consultation Now

Ready for a clear, evidence-led plan?

  • ONLINE across Ireland
  • In-person: Adare • Newcastle West  Limerick • Abbeyfeale • Midleton • Youghal • Cork • Dungarven
    We’ll review your symptoms, map likely drivers, order targeted tests (via your GP/consultant or private labs), and build a step-by-step plan integrating nutrition, Counselling & Psychotherapy, Hypnosis/Hypnotherapy, Clinical Medical Hypnotherapy and RTT.

Book a Consultation Now → Reply here and we will arrange your first appointment.

Scientific references (open-access or official guidance; exact URLs)

  1. HSE. Menopause symptoms. https://www2.hse.ie/conditions/menopause/symptoms/ (HSE.ie)
  2. NICE NG23. Menopause: identification and management. https://www.nice.org.uk/guidance/ng23 (NICE)
  3. NICE QS143 (Quality Statement 1). Diagnosing perimenopause and menopause. https://www.nice.org.uk/guidance/qs143/chapter/quality-statement-1-diagnosing-perimenopause-and-menopause (NICE)
  4. NAMS 2022. Hormone Therapy Position Statement. https://menopause.org/wp-content/uploads/professional/nams-2022-hormone-therapy-position-statement.pdf (The Menopause Society)
  5. NAMS 2023. Nonhormone Therapy Position Statement. https://menopause.org/wp-content/uploads/professional/2023-nonhormone-therapy-position-statement.pdf (The Menopause Society)
  6. BMS. Menopause Practice Standards (diagnosis & testing summary). https://thebms.org.uk/wp-content/uploads/2022/07/BMS-Menopause-Practice-Standards-JULY2022-01D.pdf (The BMS)
  7. Al-Naseem A, et al. Iron deficiency without anaemia: a diagnosis that matters. Br J Gen Pract. https://pmc.ncbi.nlm.nih.gov/articles/PMC8002799/ (PMC)
  8. British Society of Gastroenterology. Guidelines for iron deficiency anaemia in adults (2021). https://pmc.ncbi.nlm.nih.gov/articles/PMC8515119/ (PMC)
  9. NICE NG88. Heavy menstrual bleeding: assessment and management. (PDF) https://www.nice.org.uk/guidance/ng88/resources/heavy-menstrual-bleeding-assessment-and-management-pdf-1837701412549 (NICE)
  10. HSE. Iron deficiency anaemia: causes & care. https://www2.hse.ie/conditions/iron-deficiency-anaemia/ (HSE.ie)
  11. NHS. Iron deficiency anaemia—symptoms. https://www.nhs.uk/conditions/iron-deficiency-anaemia/ (nhs.uk)
  12. NICE NG145. Thyroid disease: assessment and management. (PDF) https://www.nice.org.uk/guidance/ng145/resources/thyroid-disease-assessment-and-management-pdf-66141781496773 (NICE)
  13. NHS. Underactive thyroid (hypothyroidism)—symptoms. https://www.nhs.uk/conditions/underactive-thyroid-hypothyroidism/ (nhs.uk)
  14. NHS. Overactive thyroid (hyperthyroidism)—symptoms. https://www.nhs.uk/conditions/overactive-thyroid-hyperthyroidism/ (nhs.uk)
  15. ADA. Diabetes—Diagnosis & Tests (prediabetes thresholds). https://diabetes.org/about-diabetes/diagnosis (American Diabetes Association)
  16. HSE. Pre-diabetes: diagnosis (HbA1c 42–47 mmol/mol). https://www2.hse.ie/conditions/pre-diabetes/ (HSE.ie)
  17. HSE/ICGP. Practical Guide to Integrated Type 2 Diabetes Care (diagnostic criteria). (PDF) https://www.hse.ie/eng/services/list/2/primarycare/east-coast-diabetes-service/management-of-type-2-diabetes/diabetes-and-pregnancy/icgp-guide-to-integrated-type-2.pdf (HSE.ie)
  18. Greendale GA, et al. Changes in body composition and weight during the menopause transition (SWAN). https://pmc.ncbi.nlm.nih.gov/articles/PMC6483504/ (PMC)
  19. NHS. Acanthosis nigricans. https://www.nhs.uk/conditions/acanthosis-nigricans/ (nhs.uk)
  20. CDC. Diabetes & your skin—acanthosis nigricans. https://www.cdc.gov/diabetes/signs-symptoms/diabetes-and-your-skin.html (CDC)
  21. Elkins GR, et al. Clinical hypnosis for vasomotor symptoms—RCT (Menopause, 2013). https://pmc.ncbi.nlm.nih.gov/articles/PMC3556367/ (PMC)
  22. Elkins GR, et al. Hypnosis for hot flashes among breast-cancer survivors—RCT (J Clin Oncol, 2008). https://pmc.ncbi.nlm.nih.gov/articles/PMC2652097/ (PMC)
  23. Hunter MS, et al. Is cognitive behaviour therapy an effective option for vasomotor symptoms? https://pmc.ncbi.nlm.nih.gov/articles/PMC8453849/ (PMC)
  24. NHS. Vitamins & minerals—iron (dietary sources). https://www.nhs.uk/conditions/vitamins-and-minerals/iron/ (nhs.uk)

Final thought to Remember

Your Symptoms are feedback, not your fate, you are not stuck with them. When we treat the right root cause and driver—iron deficiency, thyroid disease, insulin resistance, perimenopausal hormone change, or a combination—people can stop “putting up with it” and start feeling themselves (or even better!!)again. If you’d like a solution focused, evidence-led plan tailored to you, I’m here to help you today online or in person across Limerick, Adare, Newcastle West, Abbeyfeale, Charleville, Midleton, Fermoy, Youghal Cork and Dungarven.