The thyroid gland is responsible for controlling our metabolism, and as such, it is often blamed for causing all manner of weight loss difficulties. Heck, I had my own thyroid hormone levels checked a few years back when my dieting wasn’t producing the results I expected. In reality, though, only about 10% of women (and 1% of men) have low thyroid problems (or hypothyroidism). So it’s not likely to be the primary cause of weight loss challenges, though it’s important to diagnose and treat when present.

What do we mean by “metabolism” you might ask? It’s the rate at which your body uses fats and carbohydrates, controls your body temperature, influences your heart rate, and regulates the production of protein. When your metabolism is slow, you tend to store food as fat rather than using it for energy.

What are the symptoms of hypothyroidism?
Honest-to-goodness low thyroid hormone can cause any or all of the following symptoms:
Fatigue, weakness, weight gain or increased difficulty losing weight, dry skin and hair, hair loss, increased cold sensitivity, hoarse throat, muscle cramps, joint pains, increases in “bad” cholesterol levels (LDL), constipation, depression, memory loss, irritability, and abnormal menstrual cycles. In severe cases of low thyroid hormone production, heart failure, coma, and death can occur.

Now you’ll notice that many of these symptoms are fairly vague (and can be caused by many different things, including simple winter weather), which is why hypothyroidism often goes undiagnosed. It is reasonable, and fairly inexpensive, to check thyroid hormone levels if you are experiencing a number of these symptoms.

What causes hypothyroidism (low thyroid)?
The thyroid gland is located in your neck, just below the Adam’s apple (or windpipe), and it can be damaged by inflammation, cysts or lumps (nodules), and (rarely) cancer. Autoimmune (or Hashimoto’s) thyroiditis is the most common cause of thyroid gland damage. It is suspected that this happens during a viral or bacterial infection where the body is fighting off an invader, and in the process accidentally attacks the thyroid gland too. When the thyroid gland is damaged, it produces less (or no) thyroid hormone, resulting in a decrease in the metabolic rate of cells throughout the body.

What causes hyperthyroidism (high thyroid)?
In the opposite case, the thyroid gland may produce too much hormone. Inflammation caused by autoimmune disease (Grave’s disease), infections, and non-cancerous nodules can all trigger the gland to produce too many hormones. This can results in feelings of anxiety, nervousness, sweating, bulging eyes, trembling, rapid heart rate, skin changes and irritability.

The confusing thing is that inflammation of the thyroid gland can cause either high or low hormone output. And sometimes, the gland responds at first with high output and then eventually “burns out” and ends up not producing much hormone at all. In addition – procedures aimed at treating overactive thyroid (such as radioactive iodine or surgery) can overshoot, resulting in low thyroid hormone levels in the long run.

Not to confuse you further, but thyroid hormone levels are also regulated inside the body by two other glands located in the brain (the pituitary gland and hypothalamus). If something goes wrong with either of those two glands (or their messaging systems), it can disturb the delicate metabolic balance of the entire body.

Now one last thing I have to mention – thyroid hormone production depends on iodine. Iodine is found in our diet in the form of seafood, beans, and certain fruits and vegetables. In the United States we supplement table salt with iodine, which has virtually solved the low iodine problem for us. However, 40% of the world’s population is at risk for iodine deficiency, which can cause normal thyroid glands to be unable to produce their hormones. This results in goiters (enlarged, but non-functional thyroid tissue).

How do I keep my thyroid healthy?
The truth is, outside of getting enough iodine in your diet, there isn’t much you can do to prevent thyroid problems. Autoimmune diseases and infections, adenomas (hormone-producing lumps in the thyroid gland), and cancer can’t readily be avoided. Genetics and “luck” are generally the determinants of thyroid health (though exposure to neck radiation – from previous cancer treatment for example – is a risk factor as well). That being said, though, if you have symptoms of an overactive or underactive metabolism, it is easy enough to check your thyroid hormone levels with blood tests. The good news is that thyroid hormone can be taken in pill-form if you are in short natural supply. If you have an overactive thyroid, surgery and/or radiation can be curative.

If you find a lump in your neck (in the area of your thyroid gland) see your doctor to have it checked out. Most of the time (about 90%), these lumps are not cancerous, but are capable of over-producing thyroid hormone. Ultrasound tests, observation, or needle biopsy may be recommended for further evaluation.
In my clinical experience with patients, thyroid hormone replacement can be tricky and frustrating. Even though we can correct low thyroid hormone levels with supplements (such as Synthroid or levothyroxine) so that blood tests look “normal,” patients often tell me that they are still fatigued and are not feeling themselves. Some patients respond better to brand-name (rather than generic) thyroid drugs. In these cases I often refer them to a thyroid specialist (endocrinologist) who can further assist with medication optimization. Thyroid hormone levels (and the body’s internal control of them through the pituitary gland and hypothalamus) are actually really complicated – so if you have thyroid disease that you don’t feel is being adequately managed by your primary care physician or thyroid surgeon, don’t be shy to seek help from an endocrinologist. I do it for my patients all the time!

Now that you’ve had a health tip introduction to most of the major body parts and systems – you are ready to ask questions! If you have any more questions just Ask Hanna, our health advisors are here to help.

References
http://www.mayoclinic.org/diseases-conditions/hypothyroidism/symptoms-causes/dxc-20155382
http://www.mayoclinic.org/diseases-conditions/hyperthyroidism/basics/causes/con-20020986
https://www.thyroid.org/iodine-deficiency/#table1
http://www.cancer.net/cancer-types/thyroid-cancer/risk-factors
https://www.cancer.org/cancer/thyroid-cancer/about/what-is-thyroid-cancer.html

Image: ©Shutterstock / Emily frost