Hypothyroidism vs Hyperthyroidism: Differences, Symptoms, & Treatments

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Hypothyroidism and hyperthyroidism are both severe thyroid disorders. In hypothyroidism, the thyroid doesn’t produce enough thyroid hormone, whereas in hyperthyroidism, an overactive thyroid produces too much hormone.

About 1% of American adults experience hyperthyroidism, while approximately 5% of American adults experience hypothyroidism. More than half of thyroid disease patients may not know they have a thyroid problem.

The thyroid is a butterfly-shaped gland located in your neck, responsible for releasing T4 (a thyroid hormone) throughout the day. Your body cannot survive without it. 

Both of these disorders can be caused by autoimmune disorders. Graves’ disease can trigger hyperthyroidism, and Hashimoto’s disease can trigger hypothyroidism.

If you’re looking for a fresh perspective on treating thyroid disorders, schedule a free phone consultation with PrimeHealth experts. We will listen to your concerns and use our years of experience treating immune system disorders, like thyroid conditions, to make a plan for you.

What is the difference between hyperthyroidism and hypothyroidism?

The difference between hyperthyroidism and hypothyroidism is whether or not the thyroid gland is overactive or underactive. “Hyper” means “over,” and “hypo” means “under.” 

Both hyper- and hypo-thyroid conditions, if left untreated, can be dangerous and lead to heart disease, enlarged goiter, constant fatigue, and even death in severe cases.

Do you gain weight with hypothyroidism or hyperthyroidism? You typically gain weight with hypothyroidism. An underactive thyroid leads to excess accumulation of water and salt in the body and without the proper amount of thyroid hormone, your body does not burn calories as fast as it should. 

Can you gain weight with hyperthyroidism? You can gain weight with hyperthyroidism due to an increased appetite, but most people lose weight when they develop hyperthyroidism. 

What is hyperthyroidism?

Hyperthyroidism is when your thyroid gland produces too much thyroxine (T4), a thyroid hormone. This can increase your metabolism, leading to unintended weight loss, irregular heartbeat, anxiety, and sweating. “Hyper” is the Greek stem for “over.”

The most common cause of hyperthyroidism is the autoimmune condition Graves’ disease. Your antibodies overstimulate your thyroid to produce thyroid hormone in excess when you have Graves’ disease.

Treatment for hyperthyroidism includes medications and radioactive iodine. In severe cases, thyroid surgery may be necessary.

A functional medicine approach is extremely beneficial to both hypothyroidism and hyperthyroidism patients. In a published case of remission of Grave’s Disease (autoimmune hyperthyroidism), using lifestyle changes alone allowed a patient to normalize her thyroid markers in 6 months. 

What is hypothyroidism?

Hypothyroidism is an underactive thyroid. “Hypo” is the Greek stem for “under.”

An underactive thyroid can be caused by any of the following:

  • Primary Hypothyroidism — The disorder originates in the thyroid, with low production of thyroid hormones (T4/thyroxine and T3/triiodothyronine)
  • Secondary Hypothyroidism — The pituitary gland doesn’t produce enough thyroid-stimulating hormone (TSH), which leads to underproduction of thyroid hormones
  • Tertiary Hypothyroidism — The hypothalamus doesn’t produce enough thyrotropin-releasing hormone (TRH), often due to a mass or tumor near the hypothalamus

The most common cause of hypothyroidism is the autoimmune disorder Hashimoto’s disease. Hashimoto’s can be triggered by:

  • Hormone imbalance — If your hormone levels are not within a normal range (not just your thyroid hormone levels), Hashimoto’s thyroiditis can flare up. Thyroid hormone replacement therapy may help solve thyroid hormone deficiencies, but won’t necessarily balance your other hormones.
  • Infections Tick-borne infections (like Lyme disease) and viral infections (like Epstein-Barr) may lead to Hashimoto’s disease and, therefore, hypothyroidism.
  • Food sensitivities — Food allergens have also been known to trigger Hashimoto’s disease. Celiac disease, a gluten allergy, has been linked to an increased risk of autoimmune diseases.
  • Nutrient deficiency — Iron, vitamin A, selenium, and possibly zinc are all nutrients that interact with iodine. Deficiencies in these micronutrients may then lead to iodine deficiency, commonly associated with hypothyroidism.
  • Toxin exposure — Harmful toxins wreak havoc on your health, especially your thyroid. Heavy metal exposure, mold toxins, and exposure to chemicals like pesticides and other industrial chemicals can trigger Hashimoto’s thyroiditis.
  • Leaky gut — When the lining in your gut is chronically inflamed, the tight junction proteins in your intestinal wall may weaken and allow toxins, microbes, and food particles into the bloodstream. Leaky gut syndrome is both a cause and a symptom of Hashimoto’s. 

Which thyroid condition is more severe: hypothyroidism or hyperthyroidism?

Neither hyperthyroidism nor hypothyroidism is worse than the other, however, hypothyroidism is 5 times more common than hyperthyroidism.

Each thyroid condition, both hyper and hypo, can have uncomfortable symptoms that interfere with your quality of life, and (in severe cases) lead to death.

Hypothyroidism can lead to confusion and drowsiness, which, left untreated, can progress into a myxedema coma. There is also the risk of high blood pressure, decreased cardiac output, irregular heartbeat, and heart failure when underactive thyroid issues are not addressed.

Hyperthyroidism can also have serious heart implications. Heart palpitations and atrial fibrillation from too much thyroid hormone increase the risk of stroke and congestive heart failure.

A life-threatening condition called a thyroid storm is caused by overactive thyroid function in the body.  If you experience the following conditions, please seek out medical attention immediately:

  • Rapid heartbeat
  • Fever
  • High blood pressure 
  • Agitation and confusion
  • Loss of consciousness

Causes of Hyperthyroidism

  • Graves’ disease
  • Thyroid nodules
  • Plummer’s disease
  • Over-treatment of hypothyroidism
  • Inflammation of the thyroid (thyroiditis)
  • Toxic adenoma
  • Toxic multinodular goiter

Causes of Hypothyroidism

  • Hashimoto’s thyroiditis
  • Iodine deficiency
  • Over-treatment of hyperthyroidism
  • Thyroid surgery
  • Radiation therapy
  • Pituitary disorder
  • Thyroid cancer
  • Pregnancy

Symptoms of Hypothyroidism vs. Hyperthyroidism 

The symptoms of hyperthyroidism and hypothyroidism are opposites in most situations. Although not often, some symptoms overlap. 

Symptoms of Hyperthyroidism

  • Fatigue
  • Sensitivity to heat
  • High body temperature
  • Unintentional weight loss
  • Increased appetite
  • Anxiety
  • Irritability
  • Tremors
  • Sweating
  • More frequent bowel movements
  • Muscle weakness
  • Sleep disruptions
  • Brittle hair
  • Goiter (enlarged thyroid gland)
  • Serious eye problems
  • Menstrual changes
  • Irregular heartbeat
  • Palpitations
  • Heart disease

Hypothyroidism Symptoms

  • Fatigue
  • Sensitivity to cold
  • Low body temperature
  • Constipation
  • Weight gain
  • Muscle weakness
  • Muscle aches
  • Joint pain
  • Hoarseness
  • Dry skin
  • Thinning hair
  • Slow heart rate
  • Elevated cholesterol levels
  • Depression
  • Memory impairment
  • Goiter (enlarged thyroid gland)
  • Irregular menstrual periods
  • Myxedema coma
A Venn diagram comparing the symptoms of hyperthyroidism and hypothyroidism
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How to Treat Hyperthyroid vs. Hypothyroid Conditions

Autoimmune diseases can’t be cured, but there are treatment options to reverse the symptoms. Is hypothyroidism or hyperthyroidism easier to treat? Hypothyroidism is generally easier to treat than hyperthyroidism. 

Hyperthyroidism Treatments

Hypothyroidism Treatments

Check out our article on levothyroxine side effects to help you figure out if it’s right for you.

Diagnosing Thyroid Conditions

If you are experiencing symptoms of a thyroid disorder, you can get a diagnosis from a healthcare provider or endocrinologist. The doctor will take a medical history and perform an exam. Blood tests can be ordered to check your hormone production and TSH levels.

Autoimmune disorders that cause thyroid dysfunction use thyroid antibody tests to help make a diagnosis.

Outlook for Thyroid Disorder

According to the American Thyroid Association, there is no cure for thyroid function problems. However, our healthcare experts have personal experience with endocrine issues and success in reversing symptoms.

At PrimeHealth, we have worked with hundreds of patients dealing with thyroid disorders, especially hypothyroidism and Hashimoto’s thyroiditis. When conventional doctors say it’s incurable, we often find ways to treat and even reverse hypothyroidism permanently.

We believe in a science-based mixture of conventional and integrative medicine, as well as an individualized approach to treatment options. No one-size-fits-all plans here.

Live in the Denver area? Get a FREE in-person consultation with a member of our medical staff! Schedule your appointment today.


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