This autoimmune disorder is the most common cause of hypothyroidism.
By Jenny Ewen, BA, NREMT
Hashimoto’s disease (also known as Hashimoto’s thyroiditis) is classified as an autoimmune disorder since it’s caused by the immune system attacking the thyroid to the point where it becomes damaged. The thyroid is a small butterfly shaped gland located at the base of the neck, and creates hormones that help regulate how the body uses energy (such as calories burned, how fast your heart beats, temperature regulation).
Hashimoto’s disease is the most common cause of hypothyroidism (an underactive thyroid), which is a condition that is treatable with medication, but left untreated it causes many symptoms. In the United States alone, about five out of every 100 people have Hashimoto’s disease.
More women than men tend to develop Hashimoto’s disease (it’s about eight times more common in women); and while it can develop in younger women, it typically appears between ages 40-60, and is a genetic condition. Having another autoimmune disease can increase the risk of developing Hashimoto’s disease.
Signs and Symptoms
The disease starts slowly in the body, and no symptoms may appear for a while. Often the first symptom is when the thyroid gets larger (called a goiter) and causes the neck to appear swollen. It can sometimes feel full in the throat, but typically there’s no pain. After the thyroid becomes more damaged (over years) the goiter will shrink down to a normal thyroid size.
The chronic thyroid damage causes the amount of thyroid hormone levels in the blood to lower. From there, the signs and symptoms of hypothyroidism begin to appear as a result of an underactive thyroid gland. Early on in the progression of the disease, the hypothyroidism may have minimal symptoms, but more symptoms will appear if it goes untreated.
Signs and symptoms of hypothyroidism include:
- Fatigue and feeling sluggish
- Increased sensitivity to cold (and difficulty tolerating the cold)
- Pale and dry skin
- Weight gain
- Dry and thinning hair
- Memory problems
- Slower heart rate
- Muscle weakness and joint pain/stiffness
When hypothyroidism is left untreated, it can lead to heart problems since high levels of LDL cholesterol can occur, which leads to an enlarged heart and heart failure. It can also cause myxedema, which is a rare condition in which profound lethargy leads to a coma and requires an immediate medical intervention.
Women with hypothyroidism can experience irregular or heavy periods, and may experience difficulty getting pregnant. If a woman does become pregnant and has untreated hypothyroidism, there’s a higher risk of birth defects - these children can be more likely to have developmental and intellectual issues.
Typically, people will end up going to see a doctor due to experiencing signs and symptoms as a result of Hashimoto’s disease. The diagnosis is based on signs and symptoms and the results of blood tests, which check the level of thyroid hormones and thyroid-stimulating hormone (TSH) that are produced in the pituitary gland. An antibody check can also be performed from a blood test, and it can confirm the presence of antibodies against thyroid peroxidase (TPO - an enzyme in the thyroid gland that helps produce thyroid hormones). Most people diagnosed with Hashimoto’s disease have TPO antibodies present in their blood.
When in the past doctors couldn’t diagnose hypothyroidism until there were significant symptoms, now by checking TSH levels, a diagnosis can be made early on, maybe even before symptoms begin to develop. Experiencing significant fatigue, dry skin, or constipation may result in a doctor checking TSH levels.
If a diagnosis of Hashimoto’s disease and/or hypothyroidism is made, TSH levels will continue to be checked to help manage the disease. A doctor may start with a TSH check, then also do a thyroid hormone test to confirm the diagnosis. Sometimes they will also take an ultrasound of the thyroid to check the size and rule out any other reasons for an enlarged thyroid.
Treatment depends on how damaged the thyroid is from the disease, and whether or not hypothyroidism has developed. If there isn’t any indication of hypothyroidism, it’s possible the thyroid will just be monitored to see if anything develops.
Treatment is aimed at helping the symptoms, since there’s no current fix to stop the disease and repair the thyroid. Medication (levothyroxine) can replace the hormone that the thyroid can no longer make. The dose of the hormone will be closely monitored and changed based on TSH levels.
Once on the medication, the patient will most likely need to take it for the rest of his/her life since it will stop all the symptoms of hypothyroidism by giving the body the hormone it’s missing. Typically there are no symptoms as a result of taking levothyroxine (when it’s the correct dosage) and it’s a relatively inexpensive drug.
Sources and More Information
American Thyroid Association, “Hashimoto’s Thyroiditis (Lymphocytic Thyroiditis)” https://www.thyroid.org/hashimotos-thyroiditis/
Mayo Clinic, “Hashimoto’s Disease” https://www.mayoclinic.org/diseases-conditions/hashimotos-disease/symptoms-causes/syc-20351855
National Institute of Health - National Institute of Diabetes and Digestive and Kidney Diseases, “Hashimoto’s Disease” https://www.niddk.nih.gov/health-information/endocrine-diseases/hashimotos-disease
Office on Women’s Health, “Hashimoto’s disease” https://www.womenshealth.gov/a-z-topics/hashimotos-disease