Thyroid Deficiency and Menopause: Symptoms, Testing, and Treatment Guide

Hot flushes, fatigue, brain fog, stubborn weight-are they menopause, or is your thyroid slowing down too? When oestrogen levels shift in your 40s and 50s, the classic signs can blur. Miss the thyroid piece and you can chase symptoms for years. Here’s a clear, practical way to spot the difference, get the right tests, and manage both with confidence.

What overlaps, what’s different: a quick read and what you’re really trying to do

TL;DR

• Menopause and hypothyroidism share fatigue, low mood, poor sleep, and weight gain. Hot flushes and night sweats are more menopause; cold intolerance and constipation lean thyroid.
• Ask your GP for TSH and free T4. If TSH is high with low free T4, that’s overt hypothyroidism and usually needs treatment. Mild (subclinical) cases often need a second reading and a discussion.
• If you start oral HRT, your levothyroxine dose may need a small bump because oestrogen raises thyroid-binding proteins. Transdermal HRT is less likely to change your dose.
• Time levothyroxine well: empty stomach, same time daily, away from iron, calcium, and coffee. Re-test TSH 6-8 weeks after any dose or HRT change.
• If your main symptoms are vasomotor (hot flushes/night sweats) and thyroid labs are normal, HRT can help; thyroid tablets won’t fix hot flushes.

What are you actually trying to get done here? Most women landing on this page want to:

• Work out whether their symptoms are menopause, thyroid deficiency, or both.
• Know exactly which blood tests to ask for and when.
• Understand how HRT interacts with thyroid medication.
• Decide when to treat subclinical hypothyroidism rather than just watch and wait.
• Use day-to-day tactics (diet, timing, supplements) that actually make a difference.

A quick word on evidence and where this guidance comes from: diagnosis and treatment points here align with UK sources such as NICE guidance on thyroid disease (NG145, updated 2023), the British Thyroid Association’s statements on levothyroxine/liothyronine, and the British Menopause Society’s guidance on HRT. Screening notes reflect the USPSTF stance that there’s insufficient evidence to screen everyone without symptoms. I’ll flag where these matter.

How to get the right diagnosis: symptoms, tests, and a simple decision path

Menopause symptoms tend to fluctuate over months to years, especially in perimenopause. Thyroid symptoms build slowly and can be mistaken for “just getting older.” The fastest way to clarity is to combine a targeted symptom review with the right labs.

Symptoms that point more towards menopause:

• Hot flushes and night sweats
• Vaginal dryness and discomfort with sex
• Cycle changes (early perimenopause) and sleep disruption
• Sudden mood swings and brain fog that wax and wane

Symptoms that lean thyroid (hypothyroidism):

• Feeling cold when others are comfortable
• Constipation that’s hard to shift
• Dry skin, coarse hair, outer eyebrow thinning
• Hoarse voice, slowed reflexes, puffy face

Of course, both can cause fatigue, low mood, weight gain, and poor sleep. That’s why labs matter.

Core tests to ask your GP for in the UK:

• TSH (thyroid-stimulating hormone): the most sensitive first test
• Free T4: to confirm if the thyroid hormone level is actually low
• Consider thyroid peroxidase antibodies (TPOAb) if your TSH is borderline high or you have a strong family/personal autoimmune history; positive antibodies suggest Hashimoto’s risk

Timing and prep tips that make results clearer:

• No need to fast. Morning or afternoon is fine.
• Stop biotin supplements 48-72 hours before bloods; biotin can skew thyroid assay results.
• If you already take levothyroxine, do your blood test before your morning dose for consistency.
• Recent illness can nudge labs. If you’ve had a bad virus, consider waiting a couple of weeks unless symptoms are severe.

How to read the results (with your GP):

• Overt hypothyroidism: TSH high (often >10 mU/L) and free T4 low. Treatment with levothyroxine is usually recommended.
• Subclinical hypothyroidism: TSH above the lab range but free T4 in range. Consider repeating in 6-12 weeks, especially if TSH is only mildly raised or you just started/stopped oestrogen.
• Normal thyroid function: TSH and free T4 in range. Look to menopause management (HRT and lifestyle) for symptom relief.

Simple decision path:

1. If you have classic vasomotor symptoms and normal thyroid labs → Discuss HRT and lifestyle.
2. If your TSH is high and free T4 is low → Start levothyroxine; recheck TSH in 6-8 weeks and adjust.
3. If your TSH is mildly high but free T4 is normal → Repeat labs in 6-12 weeks; check TPO antibodies; treat if TSH persistently elevated, symptoms are significant, or there are risk factors (e.g., positive TPOAb, goitre, high lipids).
4. If you start or switch HRT → Recheck TSH 6-8 weeks later; oral oestrogen often nudges the needed thyroxine dose upward.

When to test in the first place:

• Persistent fatigue, cold intolerance, constipation, or weight gain lasting more than 6-8 weeks
• New depressive symptoms without an obvious trigger
• Goitre (enlarged thyroid) or a family history of thyroid disease
• Autoimmune history (type 1 diabetes, coeliac, pernicious anaemia)
• Medications that affect thyroid (lithium, amiodarone)
• Post-pregnancy thyroid changes (postpartum thyroiditis) if you’re in your 40s

Screening note: there isn’t a UK policy to screen all midlife women. The USPSTF also says there’s not enough evidence to screen everyone without symptoms. That’s why symptom-driven testing is sensible.

Treating both: meds that actually work, smart HRT choices, and everyday tactics

Levothyroxine (T4) is the standard treatment for hypothyroidism. It replaces what your thyroid can’t make, normalising TSH and relieving symptoms over weeks to months. Most people feel gradual improvement by 6-8 weeks once they’re on the right dose.

How to take levothyroxine for best effect:

• Take it on an empty stomach with water, same time daily.
• Wait 30-60 minutes before coffee or breakfast, or take it at bedtime at least 3-4 hours after your last meal.
• Keep it away from iron, calcium, multivitamins, soy supplements, and antacids by at least 4 hours; these block absorption.
• Be consistent with brand/formulation if you can; small differences can affect TSH.
• Recheck TSH 6-8 weeks after any dose change or if you start/stop HRT.

What about liothyronine (T3) or combination therapy? In the UK, the British Thyroid Association advises levothyroxine as first-line. A small subset who remain symptomatic with a normal TSH may be considered for a carefully monitored trial of combination therapy in specialist care. It’s not the starting point, and it’s not a menopause fix.

Now, HRT. Oestrogen helps hot flushes, sleep, mood, and bone health. For women with thyroid disease, HRT is usually fine. Two practical points matter:

• Oral oestrogen (tablets) raises thyroxine-binding globulin, which can lower free thyroid hormone levels and push TSH up. Your levothyroxine dose may need a tweak upward.
• Transdermal oestrogen (patch, gel, spray) has less effect on binding proteins, so your levothyroxine dose often stays the same.

Progestogen choice (for women with a uterus): micronised progesterone (capsules) often has a calmer sleep profile compared with some synthetic progestins. Your thyroid dosing isn’t usually affected by progestogen type.

Targets and timing:

• Most feel best with TSH in or near the lower half of the lab range (roughly 0.4-2.5 mU/L) when not pregnant. In older adults or those with heart disease, a slightly higher target may be safer-your GP will individualise.
• Don’t chase symptoms with rapid dose changes. It takes weeks for TSH and tissues to equilibrate.

Risks to watch for:

• Overtreatment with levothyroxine (TSH suppressed) can increase bone loss and atrial fibrillation risk-especially relevant after menopause. If you’re on the edge, talk to your GP about small dose adjustments.
• Untreated hypothyroidism raises LDL cholesterol and can worsen cardiovascular risk. If your TSH is high, it’s not just about fatigue.

Nutrition and supplements-what actually helps:

• Iodine: UK diets are usually adequate, but strict vegan diets can be low. Avoid high-dose kelp. If you take a supplement, keep iodine around 150 micrograms daily. Too much can backfire in autoimmune thyroiditis.
• Selenium: 55-200 micrograms/day has been studied in autoimmune thyroiditis; evidence is mixed. Don’t exceed 200 micrograms without medical advice.
• Vitamin D: common deficiency in the UK, affects bone and mood. Worth checking and replacing if low, especially if you’re choosing HRT for bone protection.
• Protein and fibre: aim for 1.0-1.2 g/kg/day of protein and 25-30 g fibre to support weight, muscle, and bowel regularity.
• Alcohol and caffeine: moderate them if sleep and flushes are rough; caffeine also interferes with levothyroxine if taken too soon after dosing.

Exercise and recovery:

• Two strength sessions a week protect muscle and bone; add brisk walking or cycling for 150 minutes/week if joints allow.
• Don’t overdo it while under-replaced; being underactive thyroid and hammering HIIT is a recipe for burnout. Build slowly as your TSH normalises.

Mood and brain fog:

• Thyroid replacement can lift low mood if it was thyroid-driven, but it won’t treat vasomotor insomnia. If sleep is fragmented by night sweats, HRT can be the missing piece.
• Short-term CBT for insomnia (CBT-I), daylight exposure, and consistent bed/wake times compound the benefits.

Checklists, examples, and answers to the questions you’ll likely ask next

Quick symptom cross-check:

• Mostly hot/cold? Hot and sweaty at night → menopause. Chilled, blanket-hunting → thyroid.
• Skin/hair? Dry skin and coarse hair happen in both; loss of the outer eyebrows leans thyroid.
• Gut? Bloating is common in perimenopause; slow, hard stools that don’t shift suggest thyroid.
• Sleep? Night sweats wake you up → menopause. Sleeping long but never refreshed → think thyroid.

Appointment prep checklist:

• Three-week symptom diary with timing (day vs night), severity, and triggers
• List of meds and supplements (note biotin, iron, calcium, PPIs)
• Family history of thyroid or autoimmune disease
• Recent infections, pregnancies, or medication changes
• Specific ask: “Could we check TSH, free T4, and TPO antibodies if my TSH is borderline?”

Levothyroxine timing cheat-sheet:

• Take on waking with water → wait 30-60 minutes for coffee/food.
• Or take at bedtime → 3-4 hours after your last meal.
• Separate by 4 hours from iron, calcium, multivitamins, and antacids.
• Keep it consistent; set a phone alarm if needed.

Decision cues for subclinical hypothyroidism (when TSH is up, free T4 normal):

• Consider treatment if: TSH persistently >10 mU/L, significant symptoms, positive TPO antibodies, goitre, high cardiovascular risk, or if you’re trying to conceive.
• Reasonable to watch and recheck in 6-12 weeks if: TSH is only slightly raised and you’re otherwise well.

Real-life scenarios

• You start oral HRT and feel great for hot flushes but energy dips again after a month. Recheck TSH; you may need a small levothyroxine increase. If you’d prefer to avoid a dose change, discuss switching to a transdermal oestrogen route.
• TSH 6.8 mU/L, normal free T4, TPO antibodies positive, and you’re exhausted. A time-limited trial of low-dose levothyroxine plus a recheck in 6-8 weeks is reasonable in discussion with your GP.
• TSH normal, hot flushes every hour, poor sleep, low libido. Thyroid tablets won’t fix that pattern; HRT, vaginal oestrogen if needed, and sleep strategies are the focus.

Mini-FAQ

• Does menopause cause thyroid disease? Not directly, but autoimmune thyroid issues often show up in midlife. The timing overlaps, which is why the mix-up happens.
• Will HRT treat hypothyroidism? No. HRT helps vasomotor symptoms, mood, and bone health. Hypothyroidism needs levothyroxine.
• Can thyroid tablets replace HRT? No. Levothyroxine won’t stop hot flushes or vaginal dryness if your thyroid is normal.
• Is thyroid disease a reason to avoid HRT? Usually not. If you’re on stable thyroid meds, you can use HRT; just recheck TSH after starting oral oestrogen.
• Do I need iodine supplements in the UK? Often not. If you’re vegan or avoid dairy/eggs/fish, consider a modest iodine supplement (around 150 micrograms daily). Avoid kelp and mega-doses.
• What about weight? Treating hypothyroidism helps, but it’s not a silver bullet. Expect modest changes once TSH is normal; pair with protein, strength training, and sleep.
• How fast will I feel better on levothyroxine? Energy and mood often pick up within 2-6 weeks once your dose is right; hair/skin changes take longer.

Next steps

• Perimenopausal with mixed symptoms: Book TSH and free T4. If normal, consider HRT for flushes and sleep; revisit thyroid testing if symptoms change.
• Already on levothyroxine and considering HRT: Prefer transdermal oestrogen if you want to minimise dose changes; if you choose oral, plan a TSH check 6-8 weeks after starting.
• Borderline TSH rise (subclinical): Repeat labs in 6-12 weeks and check TPO antibodies. Agree with your GP on criteria for a trial of treatment.
• High cholesterol in midlife: If your LDL is up, rule out hypothyroidism before starting or adjusting lipid therapy.
• Supplements: Pause biotin 48-72 hours before labs; keep iodine moderate; separate iron and calcium from your thyroid tablet by 4 hours.

Troubleshooting

• Still exhausted with a normal TSH: Check sleep quality, iron/ferritin, B12, vitamin D, depression/anxiety, and medication side effects. Not every low-energy day is thyroid or menopause.
• TSH keeps bouncing: Confirm you’re taking levothyroxine away from food, coffee, and supplements. If still unstable, ask about malabsorption, coeliac screening, or switching formulation.
• Palpitations after a dose increase: Talk to your GP; you may need a smaller step up or a slower titration, especially if you have heart disease.
• Bone health worries: If you’ve been over-replaced for a while (TSH suppressed), consider a bone density scan and discuss dose reduction; HRT may also support bone if appropriate for you.

Key sources used when shaping this guide: NICE NG145 (thyroid disease: assessment and management), British Thyroid Association and the Society for Endocrinology statements on levothyroxine and liothyronine, British Menopause Society guidance on HRT, and the USPSTF position on thyroid screening in asymptomatic adults. If your situation is complex-heart disease, long-term suppressed TSH, or persistent symptoms despite a normal TSH-ask for an endocrinology referral. You don’t have to guess your way through this.