Thyroid disorders are five to eight times more common in women than in men (Taylor et al., 2018). The trouble is that the symptoms, fatigue, weight change, a low mood, are so general that they get blamed on stress, menopause or a busy life. So an underactive or overactive thyroid can go unnoticed for years. Three blood values, TSH, free T4 and anti-TPO, usually give a first answer in a single measurement.
This is the overview article in our thyroid series. I notice that many women only think about their thyroid once the GP has ruled out everything else. That is understandable, but often late. Below you will read what the thyroid does, which symptoms fit which type, which values to measure and when a test genuinely adds something.
Where is your thyroid and what does it do?
Your thyroid is a small butterfly-shaped gland in your neck, just below your Adam's apple, in front of your windpipe. It produces the hormones T4 and T3, which regulate your metabolism: heart rate, body temperature, energy and digestion. Too little or too much thyroid hormone throws that whole system off balance.
Control runs through your brain. The pituitary makes TSH (thyroid-stimulating hormone), which tells the thyroid how much hormone to produce. That is why TSH is often the first value to drift, before you notice anything yourself. A TSH value is therefore the usual first step.
Recognising thyroid symptoms in women
Thyroid symptoms in women are often vague and develop slowly. An underactive thyroid slows your system down (tired, cold, weight gain); an overactive thyroid speeds it up (palpitations, weight loss, restlessness). Many women only realise afterwards how long the complaints had been building.
Complaints that fit an underactive thyroid (hypothyroidism):
- Persistent fatigue, even after enough sleep
- Weight gain without eating differently
- Feeling cold quickly, especially hands and feet
- Dry skin, brittle hair or hair loss
- A low or flat mood, slow thinking
- An irregular or heavier period
Complaints that fit an overactive thyroid (hyperthyroidism):
- Palpitations or a fast heartbeat at rest
- Unintended weight loss while eating normally or more
- Sweating easily, feeling hot, trembling hands
- Restlessness, irritability or poor sleep
- Needing the toilet more often, looser stools
- A lighter or skipped period
The overlap with other causes is large. Fatigue and weight change fit iron deficiency, menopause or depression just as well. So a symptom alone says little, and a blood value gives direction. See also which hormones you can test as a woman if you are unsure where your complaints come from.
Which thyroid value fits which symptom?
Not every symptom calls for the same value. The table below links common complaints to the blood value that usually says the most about them. Use it as a starting point for a conversation with your doctor, not as a diagnosis.
| What you notice | Value that gives insight | Why |
|---|---|---|
| Tired, cold, weight gain | TSH + free T4 | Points to a possibly underactive thyroid |
| Palpitations, weight loss, restlessness | TSH + free T4 | Points to a possibly overactive thyroid |
| Complaints plus thyroid disease in the family | Anti-TPO | Shows autoimmune involvement (Hashimoto) |
| Wish to conceive or pregnancy | TSH + anti-TPO | Thyroid affects fertility and pregnancy |
| Borderline TSH, yet symptoms | Free T4 + free T3 | Gives a fuller picture than TSH alone |
This table is an aid, not a replacement for medical advice. Which combination is useful for you depends on your complaints and history.
Underactive versus overactive thyroid: the difference
In an underactive thyroid the gland makes too little hormone. Your TSH then rises (your brain asks for more) and your free T4 falls. In an overactive thyroid it is the reverse: TSH falls and free T4 rises. That mirror image is the heart of the difference.
The most common cause of an underactive thyroid in the Netherlands is Hashimoto's autoimmune disease, where the immune system slowly slows the thyroid down (Chaker et al., 2017). For an overactive thyroid, Graves' disease is the best-known cause. Both are far more common in women, and often appear around hormonal transitions such as after childbirth or in the run-up to menopause.
Want to go deeper into one type? Read our separate articles on the underactive thyroid (hypothyroidism) and the overactive thyroid (hyperthyroidism).
Why does the thyroid affect women so often?
Women have a much higher risk of thyroid problems, partly through autoimmunity and partly through the interplay with their sex hormones. The risk rises around major hormonal moments: after a pregnancy and during menopause.
Oestrogen influences how much thyroid hormone is freely available in your blood. During menopause that balance shifts, and thyroid complaints are then easily mistaken for menopause complaints. They look strikingly alike: fatigue, mood swings, weight change. So it makes sense to include your thyroid when you have menopause complaints. Read more about which hormones to test around menopause.
After childbirth a temporary inflammation of the thyroid can occur (postpartum thyroiditis). It first causes fast, then slow complaints and often resolves on its own, but it deserves attention if the fatigue persists.
When is a thyroid test worth doing?
A test is mainly worthwhile if you have complaints that do not pass, or if you belong to a higher-risk group. A single measurement of TSH and free T4 then quickly gives direction: is your thyroid in balance, or not?
Consider a thyroid test if any of these apply:
- You have persistent fatigue, weight change or mood complaints
- You wish to conceive or are newly pregnant
- Thyroid or autoimmune diseases run in your family
- You recognise menopause complaints and want to rule out the thyroid
- You had an abnormal value before and want to follow it up
At Lunara you test your thyroid values without a referral. The Thyroid Complete measures TSH, free T4, free T3 and anti-TPO in one go, so you get a fuller picture than with TSH alone. If you want a simple baseline, the Thyroid Function looks at TSH and free T4.
Which values are measured?
A thyroid panel looks at a few core values. Together they tell you whether your thyroid is working too hard or too gently, and whether an autoimmune cause is involved.
- TSH is the regulator from your brain and usually the first value to change. A high TSH fits an underactive thyroid, a low one an overactive thyroid.
- Free T4 is the working storage hormone. It shows how much hormone your thyroid actually releases.
- Free T3 is the active form your cells use. It refines the picture, especially for an overactive thyroid.
- Anti-TPO are antibodies that point to an autoimmune process such as Hashimoto.
You always read a result alongside the reference range and your complaints. A value just outside the range does not automatically mean disease, and a normal value does not rule everything out. So discuss your result with a doctor.
Testing your thyroid through Lunara: how it works
You do not need a GP referral for a thyroid test. You order online, book a slot at a draw location near you (there are over 750 in the Netherlands) and have blood taken in the morning. You receive your result digitally, usually within a few working days.
Every result gets context from a BIG-registered doctor, per value. So you know not only what your TSH is, but what it means in your situation and whether a next step makes sense. For complaints involving hair or skin, see our article on hair loss and which hormones to test.
Read on in this thyroid series
Want to read further about a specific part? These articles go deeper into one theme:
- Underactive thyroid symptoms in women, for when your system runs too slowly.
- Overactive thyroid, with the symptoms and causes such as Graves.
- Thyroid values explained, what TSH, free T4 and anti-TPO mean.
- Thyroid testing, the difference between a self-test, home test and blood test.
- Thyroid and fatigue, when your thyroid is the cause of tiredness.
- Underactive thyroid and menopause, telling the two apart.
Frequently asked questions
Can I test my thyroid without a GP?
Yes. At Lunara you order a thyroid test without a referral and have blood taken at a location near you. You then discuss any abnormal result with your GP, who can refer you to an internist or endocrinologist if needed.
Which thyroid value matters most?
TSH is usually the first and most sensitive value, because it reacts first. For a fuller picture, TSH, free T4 and, when in doubt, anti-TPO are read together. One value alone rarely gives the whole picture.
Are thyroid complaints the same as menopause complaints?
They look very similar: fatigue, weight change and mood swings occur in both. That is why, with menopause complaints, it is useful to test the thyroid too, so you know which cause is involved.
How often should I have my thyroid checked?
That depends on your complaints, your history and earlier values. Discuss with your GP what suits your situation; a fixed frequency does not apply to everyone.
References
- NHG-Standaard Schildklieraandoeningen (M31). Nederlands Huisartsen Genootschap. Available via nhg.org.
- Chaker L, Bianco AC, Jonklaas J, Peeters RP. Hypothyroidism. Lancet. 2017;390(10101):1550-1562. PMID: 28336049.
- Taylor PN, Albrecht D, Scholz A, et al. Global epidemiology of hyperthyroidism and hypothyroidism. Nat Rev Endocrinol. 2018;14(5):301-316. PMID: 29569621.
Every blood test result through Lunara includes a professional assessment by a BIG-registered doctor. For treatment decisions, discuss your results with your GP.
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