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Hashimoto’s Thyroiditis vs. Graves’ Disease: A comparison of the two main autoimmune thyroid disorders 

Hashimoto’s Thyroiditis vs. Graves’ Disease: A comparison of the two main autoimmune thyroid disorders 

Hashimoto’s Thyroiditis vs. Graves’ Disease: A comparison of the two main autoimmune thyroid disorders
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The thyroid gland, a butterfly-shaped organ in your neck, plays a big role in regulating your body’s energy metabolism through the release of thyroid hormones, thyroxine (T4) and triiodothyronine (T3). However, when the immune system, your body’s natural defense system against foreign substances in the body, mistakenly targets this gland, it can lead to a condition generally known as autoimmune thyroid disease (AITD)

AITD presents clinically in two main forms—Hashimoto’s thyroiditis and Graves’ disease. Hashimoto’s thyroiditis is named after Dr. Hakaru Hashimoto, the Japanese physician who first described the condition in 1912. Grave’s disease, on the other hand, is named after the Irish doctor Robert James Graves, who first described the condition in 1835. Although a similar description was independently made by the German physician Karl Adolph von Basedow in 1840, the condition became widely known as Graves’ disease mainly in English-speaking countries, while in other parts of the world, such as mainland Europe (especially Germany) and Japan, it is often referred to as Basedow’s disease.

Despite their similarities in being thyroid-related autoimmune diseases, the impacts of Hashimoto’s thyroiditis and Graves’ disease on the body, their symptoms, and their treatments differ significantly. In this article, we will highlight the differences, and in some cases, similarities between these two diseases.

What is Hashimoto’s Thyroiditis?

Hashimoto’s thyroiditis, also known as Hashimoto’s disease or chronic lymphocytic thyroiditis, is the leading cause of hypothyroidism (underactive thyroid) in regions without iodine deficiency. It occurs when the immune system attacks the thyroid gland, causing chronic inflammation of the thyroid (a condition known as thyroiditis), gradually destroying the thyroid tissue and reducing the gland’s ability to produce hormones. This disease is more common in women than in men, and although the exact underlying cause of the autoimmune attack on the thyroid remains unknown, scientists believe genetics and environmental factors are involved.

Antibodies involved in Hashimoto’s Thyroiditis

In people with Hashimoto’s disease, the immune system produces antibodies against thyroid peroxidase (TPO) and thyroglobulin (Tg). The main antibodies involved are: 

  • Thyroid Peroxidase Antibodies (TPOAb): These are the most common antibodies found in Hashimoto’s thyroiditis. They target the enzyme thyroid peroxidase which is needed for making thyroid hormones T4 and T3.
  • Thyroglobulin Antibodies (TgAb): These antibodies target thyroglobulin, a protein involved in the storage of thyroid hormones.

The detection of these antibodies in the blood can help diagnose Hashimoto’s thyroiditis, even before symptoms become obvious.

Symptoms of Hashimoto’s Thyroiditis

  • Fatigue and sluggishness
  • Increased sensitivity to cold
  • Constipation
  • Slowed heart rate 
  • Pale, dry skin and hair loss
  • A puffy face
  • Weight gain
  • Muscle weakness, aches, and stiffness
  • Depression

What is Graves’ disease?

Graves’ disease is the opposite of Hashimoto’s in terms of thyroid function. It is the most common cause of hyperthyroidism (overactive thyroid). This disease occurs when the immune system produces antibodies that attach to the thyroid cells, stimulating them to produce excessive amounts of thyroid hormones. Like Hashimoto’s, Graves’ disease is more prevalent in women and can be influenced by genetic factors. Other risk factors identified by researchers are smoking and emotional stress.

Antibody involved in Graves’ Disease

In people with Graves’ disease, the immune system produces a specific type of antibody known as the Thyroid-Stimulating Immunoglobulin (TSI). TSI mimics the action of the thyroid-stimulating hormone (TSH), which is normally produced by the pituitary gland to regulate thyroid activity. When TSI binds to the thyroid cells, it stimulates the gland to produce excessive amounts of thyroid hormones. TSI is a subset of a broader category of antibodies known as Thyrotropin Receptor Antibodies (TRAb), which include both stimulating and blocking antibodies.

TSI can also affect tissues in the eyes and skin, leading to the distinctive eye symptoms (Graves’ ophthalmopathy) and, in some cases, pretibial myxedema, which involves swelling and thickening of the skin on the shins.

Symptoms of Graves’ Disease

  • Anxiety and irritability
  • Tremor in hands or fingers
  • Rapid or irregular heartbeat 
  • Heat sensitivity and an excessive perspiration (sweating)
  • Weight loss, despite normal eating habits
  • Enlargement of the thyroid gland (goiter)
  • Change in menstrual cycles
  • Erectile dysfunction or reduced libido
  • Frequent bowel movements
  • Bulging eyes (also the main symptom of thyroid eye disease)

Diagnosis and Treatment

The diagnoses for both conditions involve a thorough clinical evaluation. Before you’re diagnosed, your doctor will order some blood tests to measure levels of thyroid hormones and thyroid-stimulating hormone (TSH), as well as the antibodies associated with each condition. Imaging tests, such as an ultrasound of the thyroid, may also be used to examine the structure and size of the gland. For Graves’ disease, a radioactive iodine uptake test can also be a helpful diagnostic tool. While your symptoms can be useful in the assessment of your condition, doctors do not solely rely on them to make a diagnosis because thyroid symptoms often resemble symptoms of many other conditions.

Treatment for Hashimoto’s Thyroiditis

The primary treatment for Hashimoto’s thyroiditis is hormone replacement therapy with levothyroxine, a synthetic form of the thyroid hormone thyroxine (T4). This medication helps to normalize thyroid hormone levels and manage symptoms of hypothyroidism.

Treatment for Graves’ Disease

Treatment options for Graves’ disease include anti-thyroid medications, radioactive iodine therapy, and surgery. These treatments aim to reduce thyroid hormone production or remove the thyroid gland, respectively. Beta-blockers might also be prescribed to manage some symptoms associated with hypothyroidism, such as anxiety, heat intolerance, tremors, and increased heart rate.

A summary of the comparison between Hashimoto’s Thyroiditis and Graves’ Disease

Here’s a table highlighting the key differences (and similarities) between Hashimoto’s disease and Graves’ disease:

Feature

Hashimoto’s Thyroiditis 

Graves’ Disease

Type of Thyroid Dysfunction

Hypothyroidism (Underactive Thyroid)

Hyperthyroidism (Overactive Thyroid)

Primary Cause 

Immune system attacks thyroid, reducing hormone production

Immune system stimulates excess thyroid hormone production

Antibodies

Thyroid Peroxidase Antibodies (TPOAb), Thyroglobulin Antibodies (TgAb)

Thyroid Stimulating Immunoglobulin (TSI)

Symptoms

Fatigue, weight gain, cold sensitivity, constipation, depression

Anxiety, weight loss, heat sensitivity, irritability, bulging eyes (in Graves’ ophthalmopathy)

Sex Prevalence

More common in women

More common in women

Diagnosis

Blood tests for TPOAb, TgAb, TSH, and thyroid hormones

Blood tests for TSI, TSH, and thyroid hormones; possibly ultrasound or radioactive iodine uptake test

Treatment

Hormone replacement therapy (Usually Levothyroxine)

Anti-thyroid medications, radioactive iodine therapy, surgery, beta-blockers (for symptom management)

Potential Complications

Heart problems, myxedema (severe hypothyroidism)

Heart problems, osteoporosis, Graves’ ophthalmopathy, thyrotoxic crisis (severe hyperthyroidism)

 

Key takeaways

  • In autoimmune diseases, the body’s immune system mistakenly targets and attacks normal cells. In the case of Hashimoto’s and Graves’ diseases, the immune system targets the thyroid gland.
  • While both Hashimoto’s and Graves’ diseases are autoimmune conditions that affect the thyroid gland, their overall impact on the body is opposite. 
  • Hashimoto’s disease results in a decrease in thyroid hormone production, leading to hypothyroidism, while Graves’ disease increases hormone production, causing hyperthyroidism. 
  • The presence of these thyroid autoantibodies can be detected through blood tests, which is necessary for the diagnosis of both Hashimoto’s  and Graves’ diseases. For Hashimoto’s, TPOAb and TgAb levels are tested for, while for Graves’, measuring the levels of TSI is needed to make a diagnosis.
  • If you’re concerned about your thyroid function, talk to your doctor. With early diagnosis and treatment, you can manage your thyroid condition and live a full and healthy life. 

Disclaimer

At ThyForLife, we do our utmost to provide accurate information. For detailed medical information regarding diagnosis, treatment, and general practices please consult your healthcare professional. Always listen to the advice of your healthcare provider.
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