6 Signs your Thyroid is out
Tired all the time. Hair coming out in the shower drain. The number on the scale creeping up no matter what you do. Sound familiar?
It's easy to put these symptoms down to stress or hormones - and sometimes that's exactly what's going on. But these same symptoms are also classic signs of an underactive thyroid, and because they overlap with so many other conditions, thyroid dysfunction is often missed..
To make matters more complicated, the standard thyroid test — TSH — doesn't always tell the full story. Here are six signs your thyroid might be behind how you're feeling, and why it's worth digging deeper.
1. Hair Loss or Thinning
Thyroid hormone plays a direct role in the hair growth cycle. When thyroid function drops, hair follicles can shift into a resting phase prematurely, leading to thinning — often noticed at the crown, part line, or even the outer third of the eyebrows.
2. Fatigue That Doesn't Add Up
Not the "I need a coffee" kind of tired — the kind where a full night's sleep doesn't resolve it. Thyroid hormones help regulate how your cells produce energy, so when levels are low, fatigue can be constant, not matter how much rest.
3. Unexplained Weight Gain or Difficulty Losing Weight
If the scale is moving in the wrong direction — or refusing to move at all — despite consistent healthy eating and exercise, your thyroid could be part of the picture. An underactive thyroid slows metabolic rate, making weight loss an uphill battle.
4. Period Changes: Heavier Bleeds, Sore Breasts, Worsening PMS
Thyroid hormone and reproductive hormones are closely linked. Low thyroid function can lead to heavier or longer periods, increased breast tenderness, and worsening PMS symptoms - all of these symptoms are frequently mistaken for perimenopause.
5. Family History of Thyroid Disease or Autoimmunity
Thyroid conditions — particularly autoimmune ones like Hashimoto's Disease — tend to run in families. If a parent, sibling, or grandparent has a thyroid condition, or any other autoimmune disease, your own risk is higher. If you hold the gene to an autoimmune condition, your environment is the trigger, so the gene can become active at any point in your life Howver in women we see key times Hashimoto’s may become active such as during hormonal shifts such as pregnancy, postnatally, perimenopause and menopause; as well as high stress, infections or illness.
6. Your TSH Keeps Sitting on the High End
This is the sign most people (and some medical practitioners) overlook. A TSH that's repeatedly at the upper end of the "normal" range isn't nothing — it can be an early signal that your thyroid is working harder than it should to keep up. Our TSH is the ‘whip to make your bodies thyroid hormones’ so if the body is pumping out more TSH it means ‘more whip’ for a thyroid gland which is under functioning.
Why TSH Alone Isn't Enough
TSH is the standard first-line thyroid test, and it's a useful starting point — but it was never designed to be the whole picture.
Here's the problem: you can have subclinical hypothyroidism — a genuinely underactive thyroid — while your TSH still sits within the "normal" reference range. You can also have Hashimoto's Disease, the most common cause of hypothyroidism, for years before TSH rises high enough to flag it on a standard panel.
To get a true picture of thyroid health, it's worth looking beyond TSH to:
Thyroid antibodies (TPO and Tg) — to check for autoimmune activity like Hashimoto's
Full thyroid hormone panel (T3, T4, and rT3) — to see not just how much hormone is being produced, but how well it's being converted and used
Urinary iodine — since iodine is a key building block for thyroid hormone, and both deficiency and excess can affect function
If you're ticking off several of these signs and particularly if you have any family history of thyroid disease, it may be time for a more complete thyroid picture — not just a TSH result that comes back "normal."
Disclaimer: This content is for general educational purposes and isn't a substitute for personalised medical advice. Please speak with your doctor or healthcare provider about your individual symptoms and testing.
