What’s It All About …?
An estimated 1 in 4 people throughout the world have some form of thyroid disease, a risk that increases with age and for those with a family history of thyroid problems. More than half are being left without a diagnosis and therefore are not being prescribed any treatment for their condition.
Frequently misunderstood, and too often overlooked and misdiagnosed, thyroid disease affects almost every aspect of our health, so understanding more about the thyroid, and the symptoms that occur when something goes wrong with this small gland, can help you protect or regain your good health.
Women are at the greatest risk, developing thyroid problems seven times more often than men. However, it is interesting to note that more and more men over the past 6 years are joining TPAs online Thyroid Support Group.
What Does the Thyroid Do?
Most doctors will tell you it controls metabolism, which maybe sounds complicated, so well do our best to actually explain the working of the thyroid gland.
Where is the Thyroid Located?
The thyroid gland is located in the neck, just below the Adams apple. Its fairly flat, so you cant feel it (unless theres a problem). The main job of the thyroid is to secrete the thyroid hormones thyroxine (T4) and triiodothyronine (T3), which are a pair of chemicals that float through the bloodstream and, you guessed it, control metabolism. The normal thyroid gland secretes approximately 85% of the mainly inactive T4, and approximately 13% of the active thyroid hormone T3. It is T3 that every cell in your body and brain needs to make them function not T4.
What Is the Pituitary Gland?
The thyroid isnt as smart a gland as you might believe; it doesnt know how much thyroid hormone to secrete to control the metabolism at least, not on its own. That job is the duty of the tiny (pea-sized) pituitary gland, which is located at the bottom of your brain. The pituitary gland is the control centre for many glands besides the thyroid. This is covered in a later article.
How Do the Thyroid and Pituitary Work Together?
The pituitary controls the thyroid by secreting a hormone called thyroid stimulating hormone (TSH). The pituitary recognises when there are insufficient levels of thyroid hormone in the blood, so it secretes TSH to tell the thyroid to start secreting more hormones. If the body needs a lot of thyroid hormone, the TSH level goes up, and if the body has enough, the TSH level goes down.
Thats a really important thing to remember, because it gets many people confused. A high TSH means there isnt enough thyroid hormone, whereas a low TSH means theres too much. Its much like an automatic thermostat that is switched on to tell the boiler to get hot when the house is cold, and to cool down when the house is hot.
What Regulates the Pituitary?
The pituitary gland is regulated by another gland, known as the hypothalamus. Again, the hypothalamus is part of the brain and produces TSH Releasing Hormone (TRH) which tells the pituitary gland to release TSH to stimulate the thyroid gland to release more hormones. One might imagine the hypothalamus as the person who regulates the thermostat, since it tells the pituitary gland at what level the thyroid should be set.
What Do Thyroid Hormones Do?
The best analogy to explain this is: your car needs fuel to run; most cars use petrol as their fuel. Fuel gets burned in the engine and turns the wheels of the car so you can drive wherever you want to go.
The speed of the car depends on how much fuel is burned in the engine. The more fuel, the more the engine revs. The carburettor, or the fuel injectors, are the parts of the car that control the amount of fuel going to the engine, telling the engine how high to rev.
In the same way, the body needs fuel for you to function properly, like getting out of your car and going shopping. It also needs energy to keep the heart beating, the lungs breathing, and the other hormone glands working. The burning of energy to do all of these things is called the metabolism. Thyroid hormone is much like the carburettor. Low thyroid hormone levels make the body burn less energy, whereas high levels make the body burn more energy.
How Does the Thyroid Affect Metabolism?
That doesnt mean that high thyroid levels help you run fast, but it does mean that people with over-active thyroid glands tend to have higher heart rates; their muscles and hands may shake, they can lose weight, and they are nearly always hot. This is called hyperthyroidism. People with under-active thyroid glands (underlined for a specific reason and you will read and learn more about this in a later chapter) are more likely to have slower heart rates, are frequently fatigued, often gain weight, and may feel cold. Children use much of their energy to grow, so children with hypothyroidism dont grow well. That is called hypothyroidism.
I am sure there are people suffering with hypothyroidism thinking, I wish I had hyperthyroidism so I could lose weight. Dont envy them. Hyperthyroidism is actually a much more serious problem than hypothyroidism, which can be controlled with the correct thyroid hormone replacement.
What are Thyroid Tests?
Thyroid blood tests are extremely confusing to both doctors and patients. There are three main levels of thyroid hormones that are important: The TSH level, which we know the pituitary gland releases, and levels of two hormones secreted by the thyroid itself, known simply as T3 and T4. To make things more confusing, there are two types of T3 and T4 found in the blood. The majority of thyroid hormone is bound to protein and is inactive; the active portion is present in very low concentrations and is called the free T3 and free T4. Standard tests for T3 and T4 can test for the total T3 and total T4, but it is more important to test the free hormone concentrations (fT4 and fT3). Learn more about thyroid function TESTS in a later chapter.
What are the Causes of Thyroid Disease?
There are a variety of factors that can contribute to the development of thyroid problems:
- Exposure to radiation, such as occurred after the Chernobyl nuclear accident
- Radioactive iodine treatment (RAI) for Graves’ disease and hyperthyroidism typically leave patients hypothyroid
- Radiation treatment for tonsils, adenoids, lymph nodes, thymus gland problems, or acne. Nasal Radium Therapy which took place during the 1940s to 1960s, as a treatment for other ailments, or as a military submariner and/or pilot who had trouble with drastic changes in pressure
- Autoimmune Diseases of the Thyroid i.e. Hashimoto’s thyroiditis, atrophic thyroiditis, and postpartum thyroiditis
- Over-consumption of isoflavone-intensive soy products, such as soy protein, capsules, and powders
- Over-consumption or shortage of iodine in the diet can also trigger some thyroid problems. (This also applies to iodine-containing supplements, such as kelp and bladderwrack)
- Some drugs, such as lithium, amiodarone, phenytoin and carbamazepine. Certain antidepressants may cause hypothyroidism, although this is rare Interferons and interleukins used for treating hepatitis, multiple sclerosis, and other conditions. Evidence suggests that these drugs increase antibodies that put patients at risk for hypo- or hyperthyroidism. Some drugs used in cancer chemotherapy, such as sunitinib (Sunent) or imatinib (Gleevec), can also cause or worsen hypothyroidism
- A number of medical conditions can involve the thyroid and change the normal gland tissue so that it no longer produces enough thyroid hormone. Examples include haemochromatosis, scleroderma, and amyloidosis
- Failure of the pituitary gland to produce TSH (usually due to a tumour). When this happens, secondary hypothyroidism occurs
- Over consumption of uncooked “goitrogenic” foods, such as Brussels sprouts, broccoli, rutabaga, turnips, kohlrabi, radishes, cauliflower, African cassava, millet, babassu, cabbage and kale
- Surgical treatments for thyroid cancer, goitre, or nodules, in which all or part of the thyroid is removed
- Subacute Thyroiditis (temporary)
- Thyroid Dysfunction Syndromes
You have a higher risk of developing thyroid disease if, among a variety of factors:
- You have a family member with a thyroid problem
- You have another pituitary or endocrine disease
- You or a family member have another autoimmune disease
- You’ve been diagnosed with Chronic Fatigue Syndrome
- You’ve been diagnosed with Fibromyalgia
- You’re female
- You’re over 60
- You’ve just had a baby
- You’re near menopause or menopausal
- You’re a smoker
- You’ve been exposed to radiation
- You’ve been treated with lithium
- You’ve been exposed to certain chemicals (i.e., perchlorate, fluoride)
Understanding the above will help you and your medical practitioner to reach a diagnosis and, hopefully, to find the best form of treatment that will give you back your optimal health.
You might find that as well as the information in this Guidebook, it might help you even more if you join the TPA Online Thyroid Help and Support Forum.