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What is the thyroid and what does it do?

What is the thyroid and what does it do?

The thyroid is a butterfly shaped gland that sits in the front of the throat. This gland is often referred to as the “master gland” because it governs and controls so many functions in the body. One of the main roles of the thyroid is our metabolism and the speed at which the body’s internal systems function. The way that the thyroid does this is by releasing hormones: T3 and T4. These hormones fluctuate according to what the body needs at that moment in time. When the thyroid makes a lot of hormones the metabolism and bodily functions speed up and when the thyroid makes less hormones things slow down. While slight changes are normal as we go about our lives, we do want these hormones to remain somewhat stable.

What is hypothyroid?

A hypothyroid is when the thyroid hormones are consistently produced in low numbers, therefore making the thyroid underactive. When there are less hormones available for the body to use, it must slow down some of its functions. Hormones act like messengers in the body, bringing signals from the brain into our organs. Less messengers means less signals which means less tasks getting done. If you think of the body as a workplace, each organ works in a team that looks after a different job for the wellbeing of the collective. When one of the teams lags behind, it interrupts the productivity of the whole. This is why having an underactive thyroid for a prolonged amount of time can affect the whole body much more than just the momentary decrease in hormones we see from day to day.

The main symptoms felt when the thyroid is underactive are:

  • Fatigue

  • Weight gain or difficult losing weight

  • Thinning hair including the outer edges of eyebrows

  • Dry skin

  • Brain fog

  • Sore muscles and joints

  • Low appetite

  • Changes to menstrual cycle

  • Constipation

  • Intolerant to the cold

What is hyperthyroid?

Converse to a hypothyroid, a hyperthyroid is an increase in thyroid hormone production. When the body has an influx of thyroid hormones the metabolism and other body systems begin to speed up. The metabolism refers to the system in the body that turns incoming food into energy. Some people believe they have a fast metabolism, seemingly able to eat whatever they want and not put on weight. For most of these people, this is likely due to other factors outside of the metabolism such as the gut microbiome, insulin (another hormone in the body), or the type of food eaten. In overactive thyroids however, their metabolism has quickened, meaning they are processing incoming fuel much faster than the average person. As with the underactive thyroid, an overactive thyroid can affect many systems and organs in the body.

Some of the most common symptoms associated with an overactive thyroid are:

  • Losing weight or difficulty putting on weight

  • Heart palpitations

  • Increased sweating

  • Diarrhoea

  • Muscle weakness

  • Insomnia

  • Anxiety

  • Increased appetite

  • Sensitivity to heat

  • Bulging eyes

Causes of thyroid conditions?

In Australia the main cause of having a thyroid condition, both over and underactive is autoimmunity. An autoimmune condition is when the immune system targets the body’s own tissues, resulting in inflammation and potential “damage” to that tissue. When this happens in the thyroid it can result in thyroid function slowing down and becoming underactive, a disease called Hashimotos Thyroiditis. Less common but still prevalent in the general population, autoimmunity can also cause the thyroid to quicken into an overactive state, resulting in Graves Disease. Between 10-20% of the Australian population (that have been tested) have thyroid antibodies present, showing just how common these diseases are. The reasons why autoimmune diseases are on the rise are not conclusive, however, it is suspected that environmental toxins, less time outdoors, and the general western diet has played a role in this.

Diet for the thyroid

The human body is very intelligent, using intricate tools and resources to function. Some of these resources it makes itself and some it gets from the things we consume such as food, air and water. The thyroid relies on specific nutrients that we get from our food to get its job done. Some of those nutrients include iron, vitamin D, zinc, selenium, and iodine. Therefore, having a deficiency in these nutrients for long periods of time can lead to the impaired function of the thyroid. It is important for everyone, regardless of their thyroid function, to eat these nutrients including those with an overactive thyroid. Those with an underactive thyroid should pay special care to ensure they are consuming these nutrients at adequate levels, are able to absorb them by working on their gut health, or perhaps even supplementing under the supervision of a qualified practitioner.

Gluten is another important dietary factor to consider, particularly in those with Hashimotos or Graves disease. There is a strong link between coeliac disease (autoimmunity against gluten) and other autoimmune diseases, meaning those who are coeliac are at a great risk of developing conditions such as Hashimotos and Graves, and vice versa. It has been found that even non-coeliac autoimmune thyroid sufferers can benefit from a gluten free diet or from greatly reducing their gluten consumption.

Toxins and the thyroid

The thyroid is particularly susceptible to damage from toxins. In the aftermath of the 1986 Chernobyl disaster, there was a significant increase in thyroid cancer, particularly in children and young people due to their exposure to radioactive substances. Thankfully, most of us have not been and will never have that level of toxic exposure, however, that is not to discount the significance of regular low level exposure from our environment. Heavy metals such as mercury (found in fillings and seafood), aluminium (found in cookware, toiletries and vaccines), and cadmium (found in fertilisers, paint and batteries) are some of the most important to be mindful of. Tap water is another source of potential exposure to take into account. Fluoride and chlorine are found in the water here in Australia which can compete with the uptake of iodine in the thyroid, a nutrient that is especially important for efficient thyroid function. Plastics, cleaning products, skincare, fragrances, cigarettes and our food are some of our other major daily exposure sites. By filtering your water and switching to home-made, natural or organic products you can greatly reduce your toxic load.

Stress and the thyroid

Our thyroid is sent signals from the hypothalamus and pituitary gland in the brain along with our ovaries/gonads and our adrenals which also sit on the same feedback loop. Often when we see one of these glands tilt off balance, one or both of the others will follow. Our adrenals produce cortisol, a hormone that is needed for our body to deal with stress. Cortisol is not all bad, we need it to wake up in the morning and to get things done as well as to respond to danger or perceived stress. However, when cortisol is released at high levels for long periods of time, at unusual times of the day or just consistently from day to day the body remains in a continual state of fight or flight. This can impact our sleep, our mood, our digestion, our menstrual cycle, and of course our thyroid. Working on stress can make a huge improvement to the outcomes of those with thyroid conditions.

If you have already been diagnosed and are struggling, there are options out there for you. If you think you might have a thyroid condition and would like some help identifying some of your symptoms I recommend booking in an appointment where we can discuss the options for testing and support.

For more information, check out my podcast with Common Ground:

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