Tag: hypothyroid

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Health

What causes hypothyroidism?

What causes hypothyroidism? Why is hypothyroidism more common in women than men? Several hours of research into these questions did not yield all the answers I was looking for, but here is some interesting information I found about possible causes for this all too common condition.

  • Autoimmune disease, where the body’s immune system mistakenly attacks the thyroid gland, is cited as the most common cause of hypothyroidism, a decreased production of the essential thyroid hormone. Hashimoto’s Thyroiditis, the most common type of autoimmune thyroiditis, was discussed in an earlier blog. Click here to read this article.

  • Surgery, removing part or all of the thyroid, (for example, to remove thyroid nodules or cancer), can leave the thyroid with reduced ability to produce hormone, depending on the amount of gland removed.

  • Radiation of the head, neck or upper chest to treat cancer or overactive thyroid can cause loss of part or all thyroid function.

  • Thyroiditis, inflammation of the thyroid gland, is usually caused by an autoimmune attack or viral infection. The inflamed thyroid can release stored thyroid hormone initially, causing temporary hyperthyroidism, followed by reduced function and hypothyroidism.

  • Medications, for example, lithium (to treat bipolar illness), amiodarone (for heart arrhythmias), interferon alpha and interleukin-2, can prevent the thyroid gland from being able to make hormone normally. Medications are more likely to trigger hypothyroidism in those with a genetic tendency.

  • Iodine deficiency or excess – The thyroid needs iodine to make thyroid hormone, but too much can worsen hypothyroidism. The recommended daily intake is 150 mcg in adults but amounts greater than this are generally well tolerated. Authorities recommend a maximum of 1,100 mcg daily but there is controversy around this, with amounts as high as 40 mg daily being used to treat iodine deficiency in some countries.

    • Iodine is contained in various foods, such as seafood, eggs, dairy products, sea weed/sea vegetables (kelp and dulse, for example), and it is added to regular table salt. The amount of iodine in vegetables will vary, depending on how much iodine was in the soil they where they were grown.

    • Because low iodine can be a cause of severe mental retardation, as well as thyroid dysfunction, the mineral is added to table salt. However, for those with salt restricted diets, of course I this is no longer a source.

  • Genetic factors may play a role; if close family members have developed hypothyroidism, you are likely at greater risk of developing it also.

  • Pregnancy – The increase in risk is thought to be due to increased antibody production during pregnancy. Often, thyroid problems during pregnancy resolve after the birth, but the mother remains at increased of developing hypothyroidism again later in life. Note that low thyroid during pregnancy can increase the risk of miscarriage and birth defects.

Some, more controversial causes have been suggested, as researchers look for explanations for increases in occurrence of thyroid diseases:

  • Increased exposure to chlorine and fluorine (fluoride)

    • Chlorine, fluorine and iodine are in the same family of elements, and are prone to react in a similar manner. Some have suggested that ingesting chlorinated/fluorinated water might prevent iodine absorption or proper function. Sounds like the idea might hold water, but I didn’t find any studies to support this theory. I expect other factors would also need to be present to see this effect.

  • Stress may exacerbate an underlying thyroid condition (EndocrineWeb.com; Pharmacy conference)

    • Stress causes an increase in release of the stress hormone, cortisol.

      • Cortisol interferes with thyroid hormone production.

    • Production of reverse-T3 thyroid (which is inactive) rather than active T3 as a genetic response to stress is theorized to occur in dependants of populations who survived famine. This mechanism would have enabled increased chance of famine survival by slowing the metabolism and reducing need for food.

      • Today’s stresses rarely involve a lack of food, but those with this genetic trait are thought to react to modern stress as their ancestors did to the stress of famine.

    • When stressed, humans are considered more vulnerable to autoimmune disease (e.g. Hashimoto’s Thyroiditis)

    • Treating stress may help improve thyroid function, according to EndocrineWeb.com:

      • Mind/body techniques (relaxation, medication, yoga)

      • Exercise (helps reduce the effects of cortisol)

      • Sleep (helps cope with stress)

  • X-rays – If radiation treatment damages the thyroid, can low-level radiation used in x-rays cause damage over time?

    • Experts say, probably not: most radiation goes where intended. The rest of the body is exposed only to “scatter radiation”. One study (Mayo Clinic.org) estimated scatter radiation to the thyroid from a standard mammogram to be equivalent to 30 minutes of natural background radiation in the environment.

    • Repeated dental x-rays performed before 1970, when higher levels of radiation were emitted, increased risk for thyroid cancer later in life (risk of hypothyroidism was not mentioned). X-rays are safer now but the American Dental Association still stresses the need to shield the thyroid during dental x-ray examination.

    • Most mammogram clinics have thyroid guards but, generally, you need to ask for this protection. Mayoclinic.org states that thyroid guards can sometimes interfere with getting good images, so discuss this option with your doctor and/or x-ray technician.

So, what are the risk factors for developing hypothyroidism?

  • Being a woman and over age 60

    • One site suggested that women’s endocrine systems were “more sensitive”. This was the best explanation I found for why women developed hypothyroidism more often than men (doesn’t really explain much!)

  • Any autoimmune disease (for example, rheumatoid arthritis, inflammatory bowel disease)

  • Having a family history of thyroid problems

  • Treatment with radioactive iodine or anti-thyroid medications (for overactive thyroid)

  • Radiation treatment to the head, neck or upper chest

  • Thyroid surgery with partial or complete thyroid removal (amount of function will depend on how much gland was removed)

  • Pregnancy or birth within the past 6 months

How do you know if your thyroid is under performing? Here are some symptoms of hypothyroidism:

  • Fatigue

  • Dry skin

  • Constipation

  • Weight gain

  • Decreased body temperature

  • Intolerance to cold

If you have these symptoms, talk to your doctor. S/he will likely order a blood test to check your thyroid function:

  • Thyroid hormone (levothyroxine or T4) – will be below normal

  • Thyroid Stimulating Hormone (TSH) – will be elevated

    • This is the hormone that tells your thyroid to make more hormone so it increases when thyroid is low, trying to stimulate the gland to make more.

    • If too much thyroid, TSH production will be low. Tests for TSH are also used to check whether you are taking the correct dose of thyroid replacement.

    • “Normal” TSH values vary in different countries:

      • USA – 0.3 to 3.0

      • Canada – 0.5 to 4.5 or 5

      • Some authorities suggest we feel best when TSH is around 1 but in many areas anything in the “normal” range is considered fine.

      • Since excess thyroid hormone can create risk for heart disease and osteoporosis, some doctors intentionally undertreat hypothyroidism slightly.

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Book review Health

Dealing with Hashimoto’s Disease (Autoimmune Thyroiditis)

Hashimoto’s Disease is the cause of 90-95% of cases of hypothyroidism, or low thyroid. Also known as Hashimoto’s Thyroiditis, it is an autoimmune disease where specific antibodies produced in the body attack the thyroid gland, damaging it and blocking it from producing the thyroid hormones all cells in our bodies need to produce energy.

People who have Hashimoto’s generally have symptoms of low thyroid – fatigue, weight gain, feeling cold, joint and muscle pain, constipation, dry skin and hair, slow heart rate, and more – and they often have other autoimmune diseases as well, such as Type 1 diabetes, rheumatoid arthritis, inflammatory bowel disease or Celiac disease too. In addition to the typical hypothyroid symptoms, patients with Hashimoto’s may have acid reflux, nutrient deficiencies, anemia, intestinal permeability, gut dysbiosis (“bad” gut bacteria), impaired digestion, and inflammation. These symptoms suggest something more is going on…

With Hashimoto’s, as the thyroid gland is destroyed and stored thyroid hormone is released, some people will also experience transient symptoms of high thyroid – sweating, rapid heart beat, nervousness, weight loss, heat intolerance creating confusion and misdiagnoses. Hashimoto’s is the main cause of low thyroid, accounting for 90-95% of cases of hypothyroidism. The thyroid hormone replacement medication, Synthroid (synthetic levothyroxine or T4), is generally the only treatment offered and this medication is one of the most prescribed drugs in North America.

Hashimoto’s disease is diagnosed by doing blood tests. These tests will show an elevated TSH (thyroid stimulating hormone, produced in the pituitary gland in the brain, that pushes the thyroid to produce more thyroid hormone), and the thyroid hormones, T4 and T3, will be normal initially as the thyroid responds to the increased TSH. As the autoimmune damage to the thyroid progresses, levels of these thyroid hormones will start to decrease. The key diagnostic test, though, is for TPOab (anti-Thyroid Peroxidase antibodies), the antibodies that attack Thyroid Peroxidase enzyme, causing damage to the thyroid gland and disrupting production of thyroid hormones.

So far, the only standard treatment offered is replacement of the missing thyroid hormones after the disease has progressed. There is debate whether starting replacement before thyroid hormones actually start to decrease may be beneficial. While replacing thyroid hormone can help make you feel better, it does not address the underlying problem with the immune system or the cause of the disease. Wouldn’t it make more sense to determine what is causing production of antibodies, treat the cause and prevent the damage, rather than simply replace thyroid hormone for the rest of your life?

The causes are elusive, but some of the additional symptoms of Hashimoto’s, over and above those of simple low thyroid, give us some clues. With Hashimoto’s, nutrient deficiencies, food sensitivities, adrenal dysfunction (impaired ability to handle stress), impaired ability to clear away toxins and intestinal permeability are also commonly seen.

Gastroenterologist and autoimmune researcher, Dr. Alessio Fasano, suggests there are three root causes of autoimmunity, and that all three need to be present for autoimmunity to develop:

  1. Genetic predisposition (genes that increase susceptibility)

  2. Exposure to an antigen (a substance that acts as a trigger)

  3. Intestinal permeability (or leaky gut)

You can’t change the genes you inherited, but you can remove triggers or decrease intestinal permeability by improving your gut health. The problem is, the triggers and causes of intestinal permeability are not the same for everyone, making it a challenge to find the root cause.

Triggers that start the autoimmune process could be infection, severe stress, or something that causes an allergic reaction. Reviewing your past to match events with worsening symptoms is one way to identify your trigger; testing for allergens, intestinal parasites or infection is another. Making lifestyle or diet changes, such as eliminating common allergy-causing foods like gluten or dairy, switching to a Paleo diet, or doing a parasite cleanse (consult a healthcare practitioner!) and noting whether your symptoms improve can also be helpful – just keep in mind that it can take 3 to 6 months for these changes to show results. A decrease in TPOab or reduction in the required dose of thyroid supplement would also suggest you are on the right track.

Addressing digestive issues can work to decrease intestinal permeability: ensuring healthy gut bacterial flora, avoiding foods you are allergic or sensitive to, and adding the supplement, L-glutamine (2.5g twice daily increasing gradually to as high as 10g twice daily) and sometimes adding digestive enzymes are often recommended to promote healing of the gut lining.

In my research for this article, I came across a website/blog that appears very complete and well-researched: http://www.thyroidpharmacist.com . It is written by Dr. Izabella Wentz, a pharmacist with Hashimoto’s disease, who treated it successfully with lifestyle and diet changes, and now writes about her experiences, both personal and with patients she has subsequently treated. She emphasizes that it is often difficult to find and remove triggers for the disease, and to correct digestive problems, as the causes can vary from person to person. She warns readers that it can take years, but encourages them to keep experimenting until they find the solutions that improve their health.

She has written a book about her experiences and strategies to find solutions: Hashimoto’s Thyroiditis: The Root Cause. Her blog also discusses many aspects of the development of Hashimoto’s and approaches to correct the underlying immune dysfunction with good explanations of the reasons for her recommendations.

For example, there is a strong association between development of Hashimoto’s and Celiac diseases, and the two will often occur together, although sometimes without overt symptoms. Absorption of the mineral, selenium, is impaired in Celiac disease and selenium is important in thyroid function. Selenium is also needed for the conversion of low-activity T4 thyroid into T3 thyroid, a form that is 4 times more active. It also protects thyroid cells from oxidative damage caused by hydrogen peroxide that is produced during the normal production of thyroid hormones. So, two of her recommendations to try initially are a gluten free diet to prevent the Celiac process and supplementation with selenium to protect the thyroid gland cells and improve thyroid activity.

Much more research remains to be done in this area and finding the interventions that work for you can take several years, but these changes are safe to try and have the potential to reverse the autoimmune process. I would encourage you to seek a proper diagnosis if you have the symptoms described above, to educate yourself further about options, to consult with a knowledgeable healthcare professional and to work for as long as it takes to improve your health.