Low Thyroid Or Hypothyroidism: Symptoms, Causes, Solutions

Do you eat like a bird and still gain weight? Feel depressed and exhausted even though you eat well and sleep enough? Do you have high cholesterol? It might be low thyroid, also known as hypothyroidism.

Low thyroid affects one in seven people, five to eight times as many women as men, probably because women are more likely to get tested than men are.

It’s more common than most of us realize. Here’s the symptoms, causes, and some effective solutions.

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The Thyroid Hormones

Your thyroid gland sits on the front of your throat. Its primary role is to regulate metabolic rate.

The hormones include:

  • thyroid-stimulating hormone
  • thyroxine (T4)
  • triiodothyronine (T3)
  • reverse T3
  • thyroid peroxidase (TPO) antibodies.

Technically, thyroid peroxidase is an enzyme, and the test looks for antibodies to that enzyme. It’s not a hormone. However, it’s usually measured with your hormones.

Thyroid-Stimulating Hormone (TSH)

Your pituitary gland produces and secretes thyroid-stimulating hormone as means of notifying your thyroid gland to produce hormones. TSH is usually the first (and unfortunately, sometimes only) thyroid-related hormone doctors measure. TSH stimulates the thyroid gland to produce T3 and T4, the hormones that act on your cells.

Elevated TSH levels indicates your T3 and T4 may be too low. Low TSH suggests they may be too high.

When doctors test only TSH, they make assumptions about your thyroid function.

The only way to know whether your levels are optimal is to test T4 and T3.

The main difference between T3 and T4 is that T3 has three iodine molecules, and T4 has four molecules. Interestingly, almost all the body’s iodine is bound to these thyroid hormones, making iodine a critical nutrient for thyroid function.

Thyroxine (T4)

Between T3 and T4, T4 is the weaker of the two. But it is 30-100 times more concentrated in the body than T3. Even though it isn’t as powerful, there’s so much more T4 than T3 that T4 has the most significant impact on metabolism.

Free T4 is the T4 available for use by the body.

Triiodothyronine (T3)

T3 is the more potent. Some T3 is produced directly by the thyroid gland, and some is converted from T4.

Reverse T3 (rT3)

As a way to remove excess T4, the body converts T4 to rT3. Reverse T3 increases during excessive stress, chronic calorie restriction, or illness, which helps conserve energy.

Thyroid Peroxidase (TPO) Antibodies

Thyroid peroxidase is an enzyme necessary for proper thyroid function. When antibodies are present, it is a sign that your immune system is attacking TPO. Left unmanaged, you can destroy your thyroid gland. The most common thyroid-related autoimmune disease is Hashimoto’s Thyroiditis.

HormoneNormal Levels of Thyroid Hormones
Thyroid-Stimulating Hormone (TSH)0.45-4.21 mIU/L (optimal: 0.45-2.3 mIU/L)
Thyroxine (T4)0.93-1.71 ng/dL
Triiodothyronine (T3)2.3-4.2 pg/dL
Reverse T39.2-24.2 ng/dL
Thyroid Peroxidase (TPO)<34 IU/mL

The American Thyroid Association says that 12% of U.S. citizens will develop a thyroid condition during their lifetime. They also say 20 million Americans have some type of thyroid disease. If you don’t have an issue, you probably know someone who does.

The first stage of hypothyroidism is called “Subclinical Hypothyroidism.” In this stage, you have elevated TSH, but T3 and T4 are normal.

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Your thyroid regulates the speed of your muscle contraction, thinking, digestive system, energy and heat production, and most other metabolic processes. When you’re hypothyroid, you feel like you’re living in slow motion.

Hypothyroidism shares some symptoms with other conditions. You’ll even notice some symptoms as similar to symptoms of low testosterone or adrenal fatigue. The following are the most common signs and symptoms of hypothyroidism:

  • Reduced body temperature
  • Cool skin
  • Cold hands & feet
  • Dry skin
  • Reduced appetite
  • Weight gain
  • Constipation
  • Reduced muscle strength and stamina
  • Puffiness of skin, especially in the face
  • Depression
  • Rapid hair loss
  • Elevated cholesterol, and sometimes triglycerides
  • Vitamin B12 deficiency, often due to autoimmune disease
  • In women, ovaries become polycystic, which contributes to PCOS

Did you notice the bullet point about cholesterol? I’m amazed by how many patients get a prescription for statins to lower their cholesterol, yet their doctor never tests their thyroid! Medication, when used for hypothyroid patients with elevated cholesterol, consistently improves lipid levels.

Read also: Testosterone: What men, women, and parents need to know.

What Causes Hypothyroidism?

The following are common causes of hypothyroidism. These probably aren’t the only causes, but they are well-known contributors to low thyroid today.

  1. Calorie restriction: Low-calorie diets are a destructive way to lose weight. They cause massive reductions in metabolic rate, break down muscle, and are rarely effective long-term. Your body is smart. The worst part is your metabolic rate may not return to normal after you go off your diet.
  2. Insufficient dietary protein: A low-protein diet affects your body like a low-calorie diet. If you don’t eat enough protein, you can still sabotage your levels even if you eat enough calories. I almost always encourage people to eat a high-protein diet.
  3. Chronic carbohydrate restriction: A ketogenic diet offers numerous health benefits when used short-term. But, over time, keto may lead to hypothyroidism. You can probably avoid the decline by eating a healthy amount of carbs once per week.
  4. Gluten sensitivities and allergies: Gluten reduces the absorption of essential micronutrients, which causes an exaggerated immune system response. Also, gluten and thyroid peroxidase are so similar that if the immune system attacks gluten, it often attacks the enzyme in the gland.
  5. Hashimoto’s thyroiditis: Hashimoto’s is the most common cause of hypothyroidism. With Hashimoto’s, the body attacks its thyroid tissue. Eventually, when it destroys enough thyroid tissue, you can no longer produce thyroid hormone. While it is inconvenient, Hashimoto’s is not a death sentence, as you can take thyroid medication to regain normal levels.
  6. Iodine deficiency: Extreme iodine deficiency causes goiter. While goiter isn’t common in the United States, it is prevalent throughout the world. 
  7. Selenium insufficiency: Inadequate intake of selenium is also associated with low thyroid production. However, most high-quality multivitamins contain enough selenium that it shouldn’t be an issue, provided you take it every day.
  8. Goitrogens: Goitrogens are compounds found in some grains and cruciferous vegetables like broccoli and Brussels sprouts. These vegetables are great for detoxification and help remove excess estrogen from the body. But, when eaten raw, an excessive amount can block the formation of T3 and T4.
  9. Vitamin D deficiency: Low vitamin D levels are associated with autoimmune conditions. Get your vitamin D levels tested regularly, and supplement with enough vitamin D. Most people need 5000-10,000 IU per day to maintain optimal vitamin D.
  10. Genetics: Some people are born with a genetic propensity toward low thyroid production.
  11. Environmental Toxins: Environmental toxins such as heavy metals and polychlorinated biphenyls (PCBs) disrupt thyroid production. Some of the most common PCBs include phthalates, brominated flame retardants, and perfluorinated chemicals.
  12. Cancer treatment: Treatment for childhood cancer can cause hypothyroidism later in life. Radiation and medications can damage the thyroid, although symptoms may not appear until long after treatment ends. Radiation therapy for breast cancer can also damage the thyroid and cause hypothyroidism. If you receive radiation for breast cancer, be sure the radiology technician adequately shields your neck.
  13. Lithium: Doctors often prescribe lithium for severe mood disorders, and one of its possible side effects is hypothyroidism.
  14. Stress: Chronically high cortisol reduces the absorption of nutrients needed for thyroid production. Elevated cortisol also lowers TSH, reducing the production of T4 and T3. Then, low thyroid levels increase cortisol, creating a cycle of higher cortisol and lower thyroid production. 

How do you support normal thyroid function?

I always encourage people to find doctors who first try to resolve their patients’ health problems through diet, lifestyle, and supplement options, resorting to medication only when necessary. You can do a lot to support thyroid function, but many people still need a prescription, myself included.

  1. Eat some carbohydrates: With long-term use, low-carb diets decrease thyroid production in some people. A simple fix is to eat some carbs once a week. 
  2. Go gluten-free: If you have Hashimoto’s, you can’t be “mostly gluten-free” and avoid symptoms. You’re either in or out. The smallest amount can trigger an immune response, and some experts believe the reaction can last weeks to months.
  3. Follow a well-designed strength training program: The two forms of exercise I recommend for those with hypothyroidism are heavy weight training and walking.
  4. Sleep at least seven hours every night: By getting regular, quality sleep, you help your body maintain a normal circadian rhythm, enabling it to produce hormones on an expected cycle.
  5. Support your thyroid with specific supplements: Assuming you already take the Foundational Five, consider using some of the following supplements:
    • Black Cumin (also known as Fennel Flower or Nigella sativa): People with Hashimoto’s thyroiditis took a daily dose of 2 grams. The supplement lowered their TPO and TSH levels. It improved the markers of the autoimmune condition and improved thyroid function.
    • Cysteine: You’ll find it in supplements as l-cysteine, l-cysteine HCl, and n-acetylcysteine. L-cysteine is used to build glutathione, the body’s primary antioxidant. If cysteine levels drop, you can’t make glutathione, which means oxidative stress increases, lowering thyroid production.
    • Glandulars: You probably don’t eat the pituitary, thyroid, adrenals, or any other glands of beef, pork, lamb, or other meats very often. Like the glands in humans, the glands of animals provide the building blocks of hormones.
    • Adaptogens: Adaptogens are herbs and extracts that help maintain normal cortisol levels. They help bring hormones and metabolism back into balance. Some of the most potent and popular adaptogens include ashwagandha, astragalus root, cordyceps mushroom, eleutherococcus senticosus, holy basil, licorice root, Panax ginseng, rhodiola rosea, and tribulus terrestris.
    • Antioxidants and essential oils: Because oxidative stress affects thyroid function, other antioxidants may help with squelching free radicals, reducing their negative effect on thyroid function. Eat antioxidant-rich foods (i.e. blueberries, Chinese Wolfberries, dark chocolate), and consider supplementing with antioxidant-rich essential oils and botanicals.
    • N-acetyl l-carnitine: Thyroid hormone increases the excretion of l-carnitine, an amino acid essential for fat metabolism. Hypothyroid patients who begin using thyroid medication may experience a deficiency of l-carnitine, contributing to fatigue.

In a 12-week study of hypothyroid patients taking Synthroid, those who supplemented with 1980 mg of n-acetyl l-carnitine per day eliminated feelings of fatigue.

Medication Considerations

Synthroid and Armor Thyroid are the two most common medications. Synthroid is the brand name of levothyroxine, a synthetic form of T4. It’s also sold as Tirosint, Levoxyl, Levothroid, Unithroid, and Novothyrox.

Taking T4 increases T4 levels. Most people can also convert T4 to T3, so taking T4 alone may help correct T4 and T3 levels. However, some doctors find their patients do not see an improvement of T3 while taking levothyroxine. In these cases, the patients probably have an issue converting T4 to T3, so this medication may not be the most effective.

Armor Thyroid is desiccated thyroid extract. It’s like taking a glandular, except that it’s manufactured to standardize each tablet’s thyroid hormone.

Some argue that this makes it a superior form of medication. I use Armor myself.

From the research I’ve read on the two options, I don’t know that one is significantly better. Both medications improve metabolic rate, heart rate, body weight, and fluid levels. That said, a good physician will consider changes in a patient’s lab work and changes in how they feel. It may be that one type of medication helps someone feel better than another, even though both may help the thyroid levels improve.

One final thing to note…Your thyroid hormones act in partnership with many other hormones in the body.
Sometimes, low thyroid levels aren’t the issue. It’s something else.

Adrenal fatigue and hypothyroidism often go hand in hand. An experienced integrative doctor looks at all possible causes of someone’s symptoms before prescribing medication. Your job as a consumer is to select the best practitioner.


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