Hashimoto's thyroiditis (hypothyroidism)

Hashimoto's thyroiditis or Hashimoto's disease (also known as chronic lymphocytic thyroiditis) is an autoimmune disease affecting thyroid function, where the body's immune system creates antibodies that attack and inflame the thyroid.

Hashimoto's thyroiditis is the most common cause of hypothyroidism (or underactive thyroid or low thyroid) in the United States. Hypothyroidism is an endocrine disorder in which the thyroid gland does not produce enough thyroid hormone called T4 (thyroxine), which is used to help the body use energy as well help maintain function of the brain, heart, muscle, and other organs.

Hashimoto's thyroiditis is found in an estimated 17% - 20% of ME/CFS patients.

Signs and symptoms
Symptoms of an underactive thyroid (hypothyroidism) due to Hashimoto's include:
 * Weight gain
 * Hair loss (or thinning)
 * Fatigue
 * Sensitivity to cold
 * Constipation
 * Joint pain and muscle pain
 * Excessive or prolonged menstrual bleeding
 * Depression

Causes
There are many risk factors and potential causes for thyroid disease. Hashimoto's is the number one cause of hypothyroidism in the United States.

Causes of hypothyroidism include:
 * Hashimoto's thyroiditis, which is an acquired form of thyroiditis
 * Congenital hypothyroidism, which is when a person is born with hypothyroidism
 * Thyroid surgery that removes all or part of the thyroid
 * Past radiation treatment of the thyroid
 * Other causes include certain medicines, too much or too little iodine in the diet, or pituitary disease (which is another endocrine disease).

Hashimoto's thyroiditis
The exact cause of Hashimoto's thyroiditis is unknown. Many researchers and physicians believe genetics and/or a virus could play a role in the development of this autoimmune disease.

Cellular hypothyroidism
Some patients may exhibit Hashimoto's hypothyroid symptoms, yet display normal ranges in their thyroid blood tests. This could be an indication of “cellular or peripheral hypothyroidism”, where there's a deficiency at the cellular level. While thyroid hormone production may be functioning properly, the transportation of thyroid hormone into cells will be hindered if there is mitochondrial dysfunction.

Mitochondrial dysfunction has been implicated countless times, not only as a contributor to, but often cited as the immediate cause of ME/CFS symptoms.

Viral triggers
Viruses are common triggers of Hashimoto's thyroiditis, and hypothyroidism. Epstein-Barr virus (EBV) and Human Herpesvirus 6 (HHV-6) are perhaps two of the most common viral triggers for Hashimoto. Others include Herpes Simplex 1 and 2 (HSV), Cytomegalovirus (CMV), Enterovirus, and Parvovirus B19.

ME/CFS
An estimated 17%-20% of ME/CFS patients are believed to also have Hashimoto's thyroiditis.

A 2001 Swedish study of 219 chronic fatigue patients (90% women), used fine-needle aspiration (FNA) cytology to test thyroid function. 87 of 219 (40%) were diagnosed with cytological lymphocytic thyroiditis.

Studies linking viruses to Hashimoto's and ME/CFS
Studies suggesting a viral trigger for Hashimoto's thyroiditis and autoimmune thyroiditis (AIT) that are also viruses commonly associated with ME/CFS.

Sleep apnea
Hashimoto's thyroiditis (HT) and sleep apnea can both result in extreme fatigue. New evidence suggests a connection between Hashimoto's and obstructive sleep apnea (OSA). In fact, the association could be bi-directional, where either condition could potentially develop as a consequence of the other.

HLA risk alleles
Variations in several human leukocyte antigen (HLA) complex family of genes have been studied as possible risk factors for Hashimoto thyroiditis. Associations have been found between Hashimoto's disease and the following HLA alleles:
 * C*07:04
 * DQB1*03:03
 * DRB1
 * DRB1*04:10

ME/CFS and Hashimoto's genetics
In a large 2020 study, CFS patients with Human Leukocyte Antigen (HLA) risk alleles (C*07:04 and DQB1*03:03) were found to share the following autoimmune diseases, ordered by frequency:
 * 1) Hashimoto's thyroiditis
 * 2) Psoriasis
 * 3) Rheumatoid arthritis
 * 4) Alopecia areata
 * 5) Crohn’s disease or ulcerative colitis

Diagnosis
Hashimoto's thyroiditis is usually diagnosed based on multiple examinations, often beginning with hypothyroid symptom evaluation. This can be accompanied by blood tests and ultrasound.

Blood tests indicating Hashimoto's disease include elevated levels of thyroperoxidase antibodies (TPO), and elevated levels of thyroid stimulating hormone (TSH). Other lab testing can include Thyroglobulin antibodies (Tg), Free thyroxine (T4), or Free triiodothyronine (T3).

This might be followed by an ultrasound to confirm an enlarged thyroid gland, and other features of Hashimoto's thyroiditis.

Hormone Replacement
Levothyroxine - If you are found to have a thyroid hormone deficiency, resulting in elevated TSH levels, your doctor might prescribe hormone replacement therapy. Levothyroxine is a synthetic thyroid hormone used to normalize TSH and hormone levels, leading to hypothyroid symptom improvement.

Target Infection
Antivirals - If your Hashimoto's was triggered by a bacterial or viral infection, then suppressing the infection using antiviral treatment might improve symptoms.
 * Epstein-Barr virus treatment
 * HHV-6 treatment

Supplementation
Selenium - Selenium has been shown to decrease thyroperoxidase (TPO) antibody levels and improve overall symptoms associated with Hashimoto's Thyroiditis. A 2017 study demonstrated that the combination of Selenium and Myo-inositol had an even greater effect.

Supplements most commonly used to treat Epstein-Barr Virus (EBV) triggered Hashimoto's include:
 * Olive leaf extract
 * Lauricidin/Monolaurin
 * Licorice root (glycyrrhizic acid)
 * St. John’s wort
 * Echinacea
 * Vitamin C
 * Vitamin D

Immunomodulator
Low-dose naltrexone (LDN) - LDN is an immunomodulating medication that many claim has improved their Hashimoto's symptoms. However, there is a lack of scientific studies to back up this claim.

Learn more

 * Hashimoto's - Thyroid UK