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Women's Health Guide

Thyroid Health

Why women's thyroid problems get missed

1 in 20
women in the UK have a thyroid condition - many without knowing it
⚠
Medical disclaimer

This page provides general health information. It is not a substitute for personalised medical advice, diagnosis, or treatment. Every person's situation is different. If you have concerns about your health, please speak to your GP or a qualified healthcare professional.

The thyroid is a small butterfly-shaped gland in the neck that produces hormones regulating metabolism, energy, mood, temperature, heart rate and much more. When it is not working properly, the effects ripple through the whole body. Women are five to ten times more likely than men to develop thyroid disease, and the condition becomes even more common during and after pregnancy and around the menopause transition.

The two main thyroid conditions are hypothyroidism (an underactive thyroid, where not enough hormone is produced) and hyperthyroidism (an overactive thyroid, where too much is produced). Both are most commonly caused by autoimmune conditions - Hashimoto's thyroiditis in the case of hypothyroidism, and Graves' disease in the case of hyperthyroidism. Both are very treatable once diagnosed.

The problem is that thyroid symptoms are non-specific and overlap significantly with other conditions common in women - including perimenopause, iron deficiency, depression, and anxiety. This means thyroid disease is routinely missed or misattributed, sometimes for years. A simple blood test is all it takes to check.

Symptoms to know

Fatigue and low energy (hypothyroidism)
A persistent, heavy tiredness that does not improve with sleep. One of the most common presenting symptoms of an underactive thyroid, and one of the most commonly dismissed.
Weight gain or difficulty losing weight (hypothyroidism)
The thyroid regulates metabolic rate. An underactive thyroid slows metabolism, making weight gain common and weight loss disproportionately hard. This is a physiological mechanism, not a lifestyle failing.
Low mood, depression and brain fog (hypothyroidism)
Thyroid hormones directly affect neurotransmitter function and brain metabolism. Hypothyroidism can cause or worsen depression, slow thinking, and poor memory. These symptoms often improve significantly with treatment.
Feeling cold, dry skin and hair loss (hypothyroidism)
Classic signs of an underactive thyroid. Feeling cold when others are comfortable, coarse or dry skin, and diffuse hair thinning (particularly loss of the outer third of the eyebrows) are all recognised features.
Anxiety, palpitations and tremor (hyperthyroidism)
An overactive thyroid accelerates body systems. Heart palpitations, a tremor, anxiety, and feeling hot or sweaty are hallmark symptoms of hyperthyroidism and can be mistaken for panic disorder or anxiety.
Weight loss despite normal or increased appetite (hyperthyroidism)
The metabolic acceleration of hyperthyroidism can cause unexpected weight loss despite eating normally or more than usual. Combined with palpitations and anxiety, this picture should prompt thyroid testing.
Irregular periods
Thyroid dysfunction in either direction can disrupt the menstrual cycle - causing periods to become heavier, lighter, irregular or absent. Thyroid function should be checked as part of any investigation into menstrual irregularity.

What actually helps

Ask for a full thyroid panel, not just TSH
TSH (thyroid stimulating hormone) is the standard screening test and is appropriate as a first step. However, if TSH is normal but symptoms are strongly suggestive, or if TSH is abnormal, free T4 and free T3 should also be checked. Some people feel unwell with TSH levels within the 'normal' range - the interpretation of thyroid results should always be done in the context of symptoms, not numbers alone.
Ask for thyroid antibodies if autoimmune disease is suspected
Hashimoto's thyroiditis (the most common cause of hypothyroidism) and Graves' disease (the most common cause of hyperthyroidism) are autoimmune conditions. Thyroid peroxidase antibodies (TPO-Ab) and thyroglobulin antibodies confirm Hashimoto's; TSH receptor antibodies confirm Graves'. Knowing the cause matters for long-term management.
Levothyroxine works - but the right dose matters
Hypothyroidism is treated with levothyroxine (synthetic T4). Most people feel well on it once the right dose is established. However, getting the dose right can take time - TSH should be rechecked 6-8 weeks after any dose change. Some people feel better on a combination of T4 and T3, though this is specialist territory. Do not self-medicate with over-the-counter thyroid supplements.
Hyperthyroidism has several treatment options
Hyperthyroidism caused by Graves' disease can be treated with antithyroid medications (carbimazole or propylthiouracil), radioiodine, or thyroid surgery. The right choice depends on the severity of disease, the cause, future pregnancy plans, and patient preference. This should be managed by an endocrinologist. Beta-blockers can help control symptoms (palpitations, tremor) while definitive treatment is established.
Thyroid disease and pregnancy need specialist management
Thyroid hormones are essential for foetal brain development, particularly in the first trimester before the foetal thyroid is functional. Both hypothyroidism and hyperthyroidism in pregnancy carry risks and require careful monitoring and dose adjustment. If you have a thyroid condition and are planning pregnancy, discuss this with your clinician before conceiving. Levothyroxine requirements typically increase in early pregnancy.
Selenium and iodine matter for thyroid health
The thyroid requires adequate iodine and selenium to function. Iodine deficiency is rare in the UK but can occur in those who avoid all dairy and fish. Selenium supports thyroid hormone conversion and has been shown in some studies to reduce antibody levels in Hashimoto's. A balanced diet covering these micronutrients is sensible; supplementation should only be considered under guidance, as excessive iodine can worsen some thyroid conditions.

Myths worth busting

Myth
“A normal TSH means your thyroid is fine”
TSH is a sensitive screening test but it is not the complete picture. Some people have symptoms of hypothyroidism with TSH levels at the lower end of the normal range, particularly if their free T4 or T3 is also low-normal. Results should always be interpreted in the context of the whole clinical picture. If symptoms are significant and TSH is borderline, a repeat test and assessment of free T4 and antibodies is reasonable.
Myth
“Thyroid conditions only cause weight gain”
Hypothyroidism can cause weight gain; hyperthyroidism typically causes weight loss. But both conditions affect many body systems simultaneously - mood, energy, heart rate, menstrual cycle, hair, skin and temperature regulation. Thyroid disease is a multisystem condition, not a metabolic switch.
Myth
“Hashimoto's thyroiditis doesn't need treatment if TSH is normal”
If TSH is normal and symptoms are absent, monitoring may be appropriate initially. However, Hashimoto's is a progressive autoimmune condition - thyroid function should be checked at least annually, and women with Hashimoto's who are planning pregnancy may need treatment even with a normal TSH, as recommendations for TSH targets in pregnancy are tighter than in the general population.
Myth
“You should avoid gluten if you have a thyroid condition”
There is a genuine association between Hashimoto's thyroiditis and coeliac disease - the two autoimmune conditions co-occur more than would be expected by chance, and testing for coeliac disease at diagnosis of Hashimoto's is reasonable. However, a gluten-free diet has not been shown to improve thyroid function in people without coeliac disease or non-coeliac gluten sensitivity.

Frequently asked questions

What are the symptoms of an underactive thyroid in women?
The most common symptoms of hypothyroidism (underactive thyroid) are persistent fatigue, weight gain or difficulty losing weight, feeling cold, low mood or depression, brain fog, dry skin, hair loss or thinning, constipation, and irregular periods. Because these symptoms are so non-specific and overlap with many other conditions, hypothyroidism is often missed for years. A TSH blood test is all that is needed to screen for it.
How is thyroid disease diagnosed?
Thyroid function is assessed with a blood test measuring TSH (thyroid stimulating hormone), usually alongside free T4. If TSH is elevated (high), this suggests hypothyroidism; if TSH is suppressed (low), this suggests hyperthyroidism. Thyroid antibodies (TPO-Ab for Hashimoto's; TSH receptor antibodies for Graves') help identify the underlying cause. A thyroid ultrasound may be arranged if there is a goitre or nodule.
Can thyroid problems cause irregular periods?
Yes. Both hypothyroidism and hyperthyroidism can disrupt the menstrual cycle. Hypothyroidism is more commonly associated with heavy or irregular periods; hyperthyroidism can cause lighter or absent periods. Thyroid function testing is recommended as part of any investigation into menstrual irregularity, alongside other hormonal tests.
Can I get pregnant if I have a thyroid condition?
Yes, with appropriate management. Both hypothyroidism and hyperthyroidism affect fertility to some degree, but with treatment most women conceive without difficulty. If you have a thyroid condition and are planning pregnancy, ensure your thyroid function is optimised beforehand and discuss the management plan with your clinician. TSH targets in pregnancy are tighter than outside of it.
What is Hashimoto's thyroiditis?
Hashimoto's thyroiditis is an autoimmune condition where the immune system attacks the thyroid gland, causing progressive damage and, over time, reduced thyroid hormone production (hypothyroidism). It is the most common cause of hypothyroidism in the UK. It is diagnosed by finding elevated TPO antibodies alongside low-normal or elevated TSH. It tends to run in families and is associated with other autoimmune conditions including type 1 diabetes, coeliac disease and vitiligo.
Do I have to take thyroid medication for life?
For most people with hypothyroidism, levothyroxine is a lifelong medication because the underlying thyroid damage does not reverse. However, it is a simple, well-tolerated daily tablet with minimal side effects at the right dose. For hyperthyroidism, some people achieve remission with a course of antithyroid medication, particularly in milder Graves' disease. Others require radioiodine or surgery for more definitive treatment.

Sources & references

All clinical claims on this page are grounded in current evidence and published guidelines. Links open external websites.

  1. NICE CKS: Hypothyroidism
  2. NICE CKS: Hyperthyroidism
  3. British Thyroid Foundation: Patient information
  4. NHS: Underactive thyroid (hypothyroidism)
  5. NHS: Overactive thyroid (hyperthyroidism)

Last reviewed: July 2026. This page will be updated as guidelines change. If you spot an error or an outdated reference, please get in touch.

Dr Hiba Sher Khan
© 2026 Dr Hiba Sher Khan · drhiba.co.uk