Simply Explained: What is Hypothyroidism?

Originally published on 5th March 2016
Last updated on 10th June 2024

Hypothyroidism, also called an underactive thyroid or thyroid disease, is a condition where the thyroid gland (a butterfly-shaped gland in the neck) does not create enough thyroid hormone. 

The five hormones a healthy thyroid produces are: T1, T2, T3, T4 and Calcitonin. The most important are T3 and T4, with T3 being the most active.

Note: T1 and T2 may be made outside of the thyroid gland (debated).

What Are Thyroid Hormones Used For?

Thyroid hormones are needed for every process, every cell and every function within the body, so when they go wrong, i.e. are too low, a lot of other stuff can go wrong too!

This can include:

• metabolic function
• sensitivity to heat
• cold intolerance
• muscle aches and pains
• fatigue, adrenal problems
• vitamin deficiencies..
• hair loss

the list goes on. See a full list of symptoms here.

The main purpose of thyroid hormones, produced by the thyroid gland, is to ensure the metabolism is running properly.

The metabolism’s job is to produce heat and fuel. Heat to keep us warm and fuel to give us energy.

However, if we don’t have enough of those hormones, our metabolism won’t work properly and cannot provide us with adequate heat and fuel.

How Does Hypothyroidism Affect People?

People with an hypothyroidism, often have a slow metabolism, with symptoms associated with a slow metabolism, such as cold intolerance (from the lack of heat made) and extreme tiredness and weight gain (from the lack of calories burned to make energy). 

If left untreated for a long time or non-optimally treated, other on-going symptoms include those listed here and other health conditions it can cause or contribute to are shown here.

Hypothyroidism is classed as a chronic health condition or ‘chronic illness’.

Hypothyroidism affects its hosts differently, as some people report taking their medication each day and feeling fine, whereas other patients report that their medication does not help them, or that it did at one time, but not anymore.

The Issue of Treatment

This can be made worse by doctors not listening to their thyroid patients’ worries and suggestions about links to other health conditions.

Signs that their medication isn’t working well can include on-going fatigue, muscle aches, mental health issues such as depression, postnatal depression, anxiety, adrenal problems, vitamin deficiencies and diagnoses of fibromyalgia and chronic fatigue syndrome, to name just a few.

Ultimately, once thyroid levels are optimal it tends to mean that the hypothyroidism is being optimally treated, so most symptoms should start to disappear, but support for other possible problems like vitamin deficiencies and adrenal issues will need to be in place until they recover, too.

Ongoing monitoring to maintain good thyroid levels are important, which should also help keep vitamin levels and adrenal health in check, too, along with any other associated conditions.

Many thyroid patients feel their GP isn’t sympathetic enough, or willing to run all the tests they need to properly check and monitor their thyroid levels, so some turn to ordering their own additional tests.

Some thyroid patients also report their doctors being unhelpful in regards to considering other medication options, if standard T4-only medication doesn’t help them, as well as considering the fact that many other problems or health conditions can be linked to low thyroid function, especially if it’s inadequately treated.

Where To Turn for More Support?

You can find lots more, more-detailed posts on my blog about the many other areas of being hypothyroid, but this post is the general overview!

See this page too, if you’re new to the diagnosis of hypothyroidism and there is also my book, aimed at those who are new to understanding their hypothyroidism, underactive thyroid or Hashimoto’s Be Your Own Thyroid Advocate: When You’re Sick and Tired of Being Sick and Tired.

You can click on the hyperlinks in the above post to learn more and see references to information given

See also:

You, Me and Hypothyroidism: When Someone You Love Has Hypothyroidism, a book for those who know someone with hypothyroidism.

A Book for Our Children:

Thyroid Superhero: A Kid’s Guide To Understanding Their Grown-up’s Hypothyroidism, which helps children to understand their caregiver’s thyroid medication, flare days, symptoms and much more.