Understanding Thyroid Disease

When Life Sucks the Energy out of You

If you're feeling persistently below par and not managing your usual workout, your mind sometimes works overtime on what the problem could be. And it might be many things - poor diet, stress, insufficient recovery time, illness, anaemia...the list is endless.

Somewhere on that list is "thyroid problems." This article is designed to help you understand the role of thyroid hormones in the energy equation - when you need to worry and when you don't.

Many of us are fairly health-conscious and energy aware. We know what affects our performance and how we're feeling.

When it was first discovered, the thyroid gland was thought simply to give the neck a nicer shape! It sits at the front of the throat and moves up and down a little when we swallow.

It only weighs about an ounce (25 grams) but is responsible for the normal metabolism and working of every cell in the body. This awesome task is done by a balance of hormones. The thyroid uses iodine from the diet and produces 2 of its own - thyroxin (T4) and T3 - and they are kept in the right proportions by feedback to the pituitary gland in the brain. The pituitary produces Thyroid Stimulating Hormone (TSH), which, as its name suggests, stimulates the thyroid to produce thyroxin and T3.

So what happens if this all goes awry?

Step 1


If there's too little thyroxin and T3 the clinical term is hypothyroidism. The gland itself may be under-active or there may be something wrong with the TSH-producing pituitary. It's more common in women but men suffer with it too.

Symptoms of hypothyroidism vary from person to person but may include the following:

  • Weight gain - although the appetite may be normal or reduced.
  • Sensitivity to the cold - patients find that they wear more layers of clothing and muscles may feel stiff, especially when it's cold.
  • Mental slowness - you may find it more difficult to concentrate, have a poor memory and that reactions are slower. Some people suffer depression.
  • Slow heart rate - Normal resting heart rate is about 60 to 70 beats per minute. In hypothyroidism it may slow to less than 30 to 40 beats per minute, although the very fit often have a slow resting rate.
  • Constipation - The gut slows down along with everything else. The bowel's muscular wave-like contractions are fewer and less powerful so the passage of its contents slow down.
  • Women have heavier periods.
  • Skin and hair become dry and flaky due to a lack of natural oils. Some people may find the skin appears pale and puffy.

Not everyone with an under-active thyroid will suffer all these symptoms, but any number of them may take you to your doctor.

The doctor will take a history of the symptoms and some blood tests including levels of TSH, thyroxin and T3. This helps determine whether the problem originates from the thyroid or pituitary. 

When the thyroid is under-performing the blood tests will show a high TSH level and low T3 and thyroxin. If the pituitary is faulty the TSH will be low and so will the thyroxin and T3 levels.

However in mild hypothyroidism TSH is slightly high and T4 may be slightly low or normal. About 5 to 20% of people will develop more severe disease and most doctors will treat these levels if they occur more than once.

Treatment is with thyroxin replacement in tablet form. Tablets come in 25, 50 and 100 microgram tablets. The doctor will prescribe a low dose and increase it gradually and monitoring with regular blood tests. When the levels are normal and symptoms improve the tablets will need to continue for life. You need annual blood tests to check that the levels are still okay.

The causes of hypothyroidism include treatment of a pituitary disorder (by surgery or radiation therapy) or over treatment of a previously over-active gland, or autoimmune diseases.

Autoimmune disorders occur when the body doesn't recognize its own tissues and shuts down the organ it doesn't like.

Step 2

Over-production of thyroxin

Over-production of thyroxin and T3 cause the body's cells to work much harder.  So the picture is the reverse of the one described above.

It is referred to as hyperthyroidism or thyrotoxicosis.

Here the cause might be a viral illness (thyroiditis), a goitre (swelling) of the thyroid producing extra hormone, or an autoimmune disease (often called Grave's Disease). 

Rarely, the pituitary gland may over-produce TSH.

Symptoms you might have if the gland is over-active include diarrhoea, mental irritability and lack of concentration. Also sensitivity and intolerance to heat, sweating more than usual, weight loss often with an increased appetite, which can include muscle loss in severe cases, fast heart rate. In women there are often menstrual disturbances.

Again the doctor will listen to your symptoms and this time blood tests will show a low TSH and high thyroxin and T3.

However treatment is more complex than in under-activity. You would probably be referred to a specialist (an endocrinologist) who will offer medicine or surgical options. 

Medicines aim to block the activity of the gland and then to replace it in a controlled way with artificial thyroxin - i.e. tablets. This is called the block-replace regimen. This is successful in about 50% of people; in others a relapse might occur.

Alternatively a special preparation of iodine is designed to concentrate in the gland and obliterate its function. Again a repeat dose may be needed in 50% of cases.

Surgical removal of the gland, or part of it, is the other option.

In all cases or hyperthyroidism it's difficult to gauge the treatment so that the thyroid returns to normal without the need for tablet treatment.

The specialist helps guide the patient to the best, informed decision for his type of disorder.

In both under- and over-active disease, treatment won't make you feel better instantly and follow up with your doctor is usually lifelong.

There are lots of things that cause energy to rise and fall. Sustained periods of symptoms shouldn't be ignored so consider a discussion with your physician to set your mind at rest.

There are lots of things that cause energy to rise and fall. Sustained periods of symptoms shouldn't be ignored so consider a discussion with your physician to set your mind at rest.


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