Underactive thyroid: when normal isn't optimal.

I want to begin this post with something personal.

Many winters ago, I found myself in a place so dark that I genuinely wondered whether feeling well was still possible for me. I questioned whether something inside me had broken beyond repair.

I was deeply anxious and low. Crying became my default setting, weight kept creeping up, the fatigue was crushing. Walking downstairs to the kitchen and back up to the bedroom felt like the achievement of the day. I was constantly cold, my knees, hips and fingers ached around the clock.

Of course I went to my GP.
Of course my blood results came back “normal”.

I was told to lose weight, to go to the gym, to eat less.

I say that with a gentle smile now. I know it was meant well.

But it completely missed the mark.

Today I want to talk to you about underactive thyroid and its many faces.

Because thyroid health is often far more relevant in midlife than we realise.

We blame our low energy on stress. On busy schedules. On fluctuating hormones. And yes, sometimes that is true. But overlooking the thyroid in the bigger picture of midlife health can be a costly mistake.

Especially in late perimenopause and menopause, when declining oestrogen can influence even a previously healthy thyroid.

Whenever a new client walks through my virtual door and fatigue is part of her story, thyroid function is one of the very first things I assess.

Persistent fatigue is a hallmark sign of hypothyroidism.

It is that feeling that no matter how much you rest, your battery never quite reaches 100 percent. And whatever charge you do have disappears far too quickly.

A quick fact for you. Hypothyroidism is eight to nine times more common in women than in men.

Other common symptoms include:

• Aching joints and muscles
• Gradual, stubborn weight gain
• Hair thinning and brittle nails
• Dry, itchy skin
• Low mood or anxiety, sometimes that dreadful sense of doom in the morning
• Constipation, especially if you are not going daily or you strain
• Feeling cold when everyone else feels fine
• Low libido

The list is longer and symptoms vary from woman to woman, but these are some of the more universal patterns I see.

And here is the frustrating part.

You go to your doctor. Blood tests are run. The results come back “normal”. You are sent home with reassurance and little else.

Most often only two markers are checked: TSH and T4.

There are two main problems with this approach.

First, those two markers alone are not enough to give a full picture of thyroid function.
Second, the reference ranges commonly used are wide and outdated.

So many women are told their thyroid is fine when in reality there is significant room for improvement.

To help with this, I created a simple cheat sheet. It shows current NHS reference ranges alongside more optimal ranges where women typically feel their best.

There is one very important addition to this conversation.

If your test shows thyroid antibodies, specifically TPO or TgAb, above 10, this indicates an autoimmune process affecting the thyroid. This is called Hashimoto’s, or autoimmune thyroid disease.

And it is something that should be addressed early.

So if you were told nothing is wrong and that it is “all in your head”, please know this. That is not necessarily true. It may simply mean you have not been tested thoroughly.

Two easy starting points in the UK are the Advanced Thyroid Function test by Medichecks or the Thyroid test by Thriva. Both are affordable home finger prick kits and a good place to begin.

Now let’s talk about why the thyroid struggles in the first place.

It is rarely just one thing. By midlife, our bodies have lived through stress, pregnancies, infections, emotional strain, nutrient depletion. It becomes a collection of factors.

Common contributors include:

• Chronic stress. Living in survival mode suppresses thyroid function.
• Low mineral levels, especially iron, magnesium, selenium and zinc. Iodine needs caution, particularly in autoimmune cases.
• Inadequate protein intake. Thyroid hormones are built from amino acids.
• Suboptimal vitamin D levels. Ideally we want them closer to 100 nmol/L or above.
• Liver health, which is crucial for converting thyroid hormones into their active form.
• Digestive function and gut health, which play a much bigger role than most people realise.

Let me pause on the gut for a moment.

Around 90 percent of underactive thyroid cases are linked to Hashimoto’s, an autoimmune condition where the immune system attacks the thyroid gland.

If you have been diagnosed with Hashimoto’s and are taking thyroxine or another thyroid hormone, please hear this clearly.

Your medication is essential. It provides the hormone your body needs. But it does not address the underlying immune imbalance.

Calming the immune system and reducing inflammation is key to slowing further thyroid damage and improving quality of life.

Autoimmune conditions cannot be “cured”, but they can absolutely be guided into remission. With the right support, many women feel dramatically better.

And once again, the gut is central.

Inflammation, increased gut permeability, infections, bacterial overgrowth, food intolerances and poor nutrient absorption all influence thyroid health. Particularly in Hashimoto’s.

The good news is that there is so much we can do.

Simple foundations around food, targeted supplementation, stress regulation and gut repair can transform how your thyroid functions and how you feel day to day.

So if you are reading this and quietly recognising yourself in these symptoms, here is my suggestion.

Do not guess. Guessing is often the longest and most expensive route.

Test properly. Compare your results with optimal ranges. Check for antibodies. If there is room for improvement, start with the fundamentals we have discussed.

And if it all feels overwhelming, you do not have to navigate it alone.

You are very welcome to book a free 30 minute discovery call with me. We can talk about your symptoms, your goals and what a clear, realistic plan could look like for you. There are different ways to work together, including options that are budget conscious.

Your fatigue is not a personality flaw.
Your weight gain is not a moral failure.
And your symptoms are not imaginary.

There is always a reason. And there is always a path forward.

In health,
Olga