Hypothyroidism and Hyperthyroidism: What's the Difference?

We all hear about the thyroid gland and that our metabolism takes a hit if it isn't functioning well. But do we really know what that means?

The thyroid is a small, butterfly-shaped gland right below the Adam’s apple and just above the collarbone. It produces two very important hormones that affect almost every aspect of your metabolism, which is how your body operates or runs.

Thyroid hormones maintain how fast your body burns fats and carbohydrates, control your body temperature, influence your heart rate, and help regulate your body’s production of proteins.

So you heard it right! This crucial gland does have a huge impact on your metabolism and your health.

The thyroid can malfunction in various ways. The most common terms we hear when it comes to its diseases are “hyperthyroidism” and “hypothyroidism”. These two can easily get mixed up, however they are completely different conditions.

Let’s find out what these diseases really mean, how you can become aware of the symptoms, and the available treatment options out there that can make you feel better.

Hyperthyroidism

This condition occurs when your thyroid gland produces too much of its hormones, making you feel nervous, shaky, agitated and irritable. Hyperthyroidism can make you sweat more, cause your heart to beat faster, and make your hands and fingers tremble.

Additional symptoms include difficulty sleeping, fatigue, muscle weakness, lighter and less frequent menstrual cycles. You may also experience increased appetite, and unexplained and sudden weight loss.

The initial symptoms of hyperthyroidism can be mistaken for other things, such as too much stress or too little sleep. However, if you can’t seem to shake off these symptoms, you should consult your doctor and ask if you might be suffering from a thyroid condition.

Paying attention to these symptoms and taking initiative is important, because if left untreated, hyperthyroidism can lead to some severe health conditions.

Hyperthyroidism can interrupt your bones' uptake of calcium and cause brittle bones (osteoporosis). You may experience problems with your eyes or your heart, or develop red, swollen skin on your shins and feet.

You could even have a condition called thyrotoxic crisis, which is a sudden worsening of the disease accompanied by fever, fast pulse, restlessness, agitation, as well as decreased awareness and even mental clarity.

More than 70 percent of hyperthyroidism cases are caused by an autoimmune disorder called Graves’ disease. Autoimmune diseases cause your immune system to attack your own body.

With Grave’s, immune system cells stimulate the thyroid to produce more of its hormones, leading to hyperthyroidism. Grave’s is most common among young women and can also run in families.

It may affect the eyes, pushing them forward and making them appear bulged. It causes them to be dry, red, swollen, and uncomfortable.

Hyperthyroidism can also occur due to a nodule or lump on your thyroid, or an infection that inflames the thyroid gland, causing it to release more of its hormones.

Your doctor can diagnose hyperthyroidism by examining the thyroid and looking for rapid pulse, changes in your eyes, and a slight shaking of your hands.

A blood test can also measure the amount of thyroid hormones in your body. If the results come back positive, your doctor will do a thyroid scan to see if you have Grave’s diseases or any hyperactive nodules or lumps on your thyroid.

Based on your physical condition, age, and cause of hyperthyroidism, your doctor will choose the most appropriate treatment for you. You might be prescribed radioactive iodine, which is a substance that gets absorbed by the overactive thyroid cells and decreases the production of thyroid hormones.

This treatment can diminish your symptoms in three to six months.

Antithyroid medicine can also be prescribed. These pills block the gland’s ability to produce hormones, improving your symptoms in 6-12 weeks. The treatment usually lasts a year.

Your doctor might also recommend surgery and remove a big part of your thyroid gland to prevent excess hormone production.

These treatments might suppress the production of thyroid hormones to the point where there is an inefficient supply of thyroid hormones in your body, which is what hypothyroidism actually means.

Hypothyroidism can be corrected with a thyroid hormone supplement.

In addition to your treatment, your doctor may also prescribe beta blockers to slow down your heart rate, nervousness and tremors until your hormone levels get back to normal.

Hypothyroidism

Hypothyroidism occurs when your thyroid gland is not making enough hormones to keep your body up and running at normal speed. Women, especially those older than 60, are more likely to experience this condition.

It may take a number of years for symptoms to emerge. Initial symptoms, such as fatigue and weight gain, can be barely noticed, or may simply be attributed to aging.

But as your metabolism continues to slow down, more serious symptoms can occur. You may experience constipation, dry skin, aches and stiffness, muscle weakness and depression. Your face can become puffy, your hair may thin, your heart rate may decrease, and your memory could become impaired.

You may suffer from an increased sensitivity to cold. Your cholesterol levels may rise. Your joints could become painful and swollen. Your menstrual periods can become heavier or irregular.

Constant stimulation of your thyroid gland to produce more hormones can also cause it to become enlarged. This condition is called a goiter.

It is important to be on the lookout for these symptoms and never underestimate them. Talk to your doctor if you are experiencing unexplained fatigue, sudden weight gain, or any of the described symptoms above.

You may be at increased risk for hypothyroidism if you have an autoimmune disorder or if you have previously been treated for hyperthyroidism.

Having thyroid surgery, where all or a large portion of your thyroid has been removed, or receiving radiation therapy to your head or upper chest can also cause hypothyroidism.

Certain drugs such as lithium may also cause this condition, so ask your doctor about the effects of the medication that you are taking may have on your thyroid gland.

The good news is that hypothyroidism can be tested and diagnosed with a thyroid function test, and safely and effectively treated with a synthetic thyroid hormone.

With this medication you will start to feel less tired in one to two weeks, your cholesterol levels will gradually decrease, and you will start losing the extra weight.

The treatment usually lasts a lifetime. Your doctor will find the right dose for you and may change it from time to time based on your annual thyroid function tests.

Your doctor might recommend annual thyroid hormone tests if you are above a certain age, but it is always important to listen to your body and be aware of suspicious changes.

Always be proactive and consult your doctor if you notice any of these symptoms. Your thyroid might be asking for help!

Sources:

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JR Reid, J. R., Wheeler, S. F. Hyperthyroidism: Diagnosis and Treatment. American Family Physician. 2005, Aug; 72(4):623-630.
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Reviewed February 3, 2015
by Michele Blacksberg RN
Edited by Jody Smith