Spotting the signs of an underactive thyroid

Elisabeth Carlsson
By Elisabeth Carlsson,
updated on May 12, 2023

Spotting the signs of an underactive thyroid

An expert look at how to help the furnace of the body function effectively

Crushing fatigue, brain fog, the inability to wake-up properly, feeling cold (especially in your hands and feet), low mood, and feeling a bit ‘blah’ – do these symptoms sound familiar? You might just find a number of reasons as to why you feel like this, whether it’s due to cold weather and a lack of sun, a busy job, or stressful mornings getting kids ready for school. Maybe you also have issues with poor memory, digestion, high cholesterol and blood pressure, and have noticed your hair seems to be falling out. Is it just living a typical busy life, or perhaps something else?

What if I told you these complaints might be signs of a low thyroid function, and could be improved by making changes to your lifestyle and nutrition?

According to the NHS patient information site, one to two people in 100 are suffering from low thyroid function in the UK, with it also being 10 times more common in women, and many of the symptoms explained above are signs that your thyroid needs some attention. But what many experiencing these symptoms struggle with is that they sound quite general, so it can be brushed off as part and parcel of modern living, and therefore tricky to diagnose.

What is the thyroid?

The thyroid is a butterfly-shaped gland, which is part of your endocrine system, and sits at the base of your neck. It controls your metabolism, or at what rate the body burns food for energy. The thyroid also controls many other bodily functions, including your heart rate, body temperature, weight, menstrual cycle, muscle strength, and nervous system, through producing and releasing hormones into your bloodstream, so you can see why so many functions of your body start to slow down when your thyroid is not operating efficiently. In essence, the thyroid hormone is necessary for all forms of organised biology.

What to expect when seeking support for your thyroid

If you’re concerned about your symptoms, reaching out to your doctor is an important first step. However, it’s worth being aware that getting a diagnosis isn’t always straightforward. If your GP does a thyroid test, the results can often come back as normal, which can feel deflating by not giving you an answer. But one issue with UK lab tests is that they can be limited in what they test, and feature narrow ranges, resulting in an unsatisfactory understanding of why a person might be experiencing hypothyroid symptoms, as noted by charity Thyroid UK.

Without getting too technical, some tests can focus on the specific hormone levels, and not take into account if your cells have a reduced sensitivity to the thyroid hormone, meaning you could be more resistant to it. In the past, high cholesterol was a diagnostic tool for hypothyroidism, and could be a warning sign of thyroid issues, suggesting that thyroid tests should be run if high cholesterol shows up in tests, as documented in the journal JAMA Internal Medicine.

How should your thyroid work?

The thyroid uses two primary thyroid hormones, T3 and T4, which reach almost every cell in your body, and when they are out of balance it can lead to many of the problems already discussed. The thyroid and the brain work together, communicating constantly in a feedback loop. If more T3 or T4 is needed, your brain will send chemical messages to get the process started to produce more. At least, this is how it’s supposed to work.

What factors can affect your thyroid function?

Unfortunately, the feedback loop between the thyroid and the brain is easily disrupted if you don’t get enough specific micronutrients, such as iodine, selenium, and A and B vitamins. Also, too many refined carbs and not enough protein can interfere with the conversion of T4 to T3, and, beyond nutrition, your environment and stress can have a major influence, too.

However, even though micro nutrients are important, I find that it’s equally important to look at the right type and level of macronutrients, i.e. fats, carbohydrates, and protein, which can also make dietary choices easier.

How to better support your thyroid function at home

Protein: This is essential for thyroid function, and in most cases people don’t eat enough. Adequate animal protein is required for the production of the thyroid hormone, and for the conversion of T4 to T3. The type of protein is important, so, for example, muscle meat is higher in some amino acids that, while important, could have a thyroid suppressing effect. Focus more on nose to tail eating, including organ meats like liver and try gelatinous cuts of meat to make the dish osso bucco, for example. Fish and seafood are all good choices especially as they contain so many important minerals like selenium and iodine. And for non-meat eaters, you could focus on plant proteins such as tofu, tempeh, lentils, or spirulina.

Carbohydrates: Glucose is needed by the liver cells to produce the active T3 thyroid hormone. So when carbohydrates are restricted, or the body is under stress, it needs to get its energy from muscle tissue. This leads to an increase in stress hormones like cortisol and adrenaline to compensate for the deficiency of energy, glucose, and oxygen. This is why long-term restrictive dieting can have such negative effects on metabolism. Focus on easily-digested carbohydrates like root vegetables, squashes, ripe fruits, and fresh fruit juices.

Fats: Saturated fats like butter are more stable, and animal sources tend to be higher in pro thyroid nutrients like vitamin A and K2. Extra virgin olive oil and coconut oil are also good choices, with the latter containing butyric acid, which helps thyroid hormone move into the brain by increasing T3 uptake by glial cells.

Stress reduction: Focusing on stress reduction should also be a cornerstone for anyone who wants to improve their thyroid health. Do things like gentle exercise, getting out in nature, and focusing on getting a good night’s sleep. The production of cortisol is a life-saving response, but in a hypothyroid person, it occurs abnormally in an attempt to keep blood sugar up. Cortisol is released when our bodies are under stress, so it’s important to look at diet and stress levels.

Check your metabolism: When your cells produce energy, they also produce heat, and so a simple test was created by Dr Broda Barnes. Simply check your basal temperature, so first thing in the morning you should be seeing temperatures around 36.7oC/98oF, and after eating and as the day goes by this should increase to around 37oC/98.6oF. Please note that women’s basal temperature will increase during ovulation, and that it’s a good indicator but not a definite test.

If you are experiencing any of the things mentioned in the article, do remember that there are lots of things you can do, so don’t be disheartened if you struggle to feel heard or get a clear diagnosis initially. Instead, use this knowledge to ask for the right tests, and seek help, because so many health issues can be resolved at the root cause by restoring thyroid function.

Find out more at Nutritionist Resource.

Join 100,000+ subscribers

Stay in the loop with everything Happiful

We care about your data, read our privacy policy
Our Vision

We’re on a mission to create a healthier, happier, more sustainable society.