Is Hashimoto's Thyroiditis a Genetic Disorder?
Hashimoto’s thyroiditis is an autoimmune disease, wherein the immune system turns against the body's healthy cells. In people with Hashimoto’s disease, their immune system attacks the thyroid gland. The thyroid gland is a small gland located at the base of the neck just below the Adam's apple. The thyroid gland is a part of the endocrine system. It is also the production center for the hormones that are responsible for coordinating the body’s activities.
When Hashimoto's disease strikes the immune system, it goes against the thyroid gland. The immune system's reaction leads to hypothyroidism. As a result, in people with Hashimoto’s disease, the thyroid glands are rendered incapable of making enough hormones to the body’s needs. The hormones generated by the thyroid glands are the ones that regulate the body's metabolism. Therefore, people with Hashimoto’s thyroiditis tend to have an impaired metabolism.
Hashimoto’s disease has been shown to be the predominant cause of hypothyroidism in America. Thyroid hormones are given to supplement the body’s needs, and thereby, treating the disease. It is more common in women, more so the middle-aged women in comparison to men and children. It is also known as "chronic lymphocytic thyroiditis."
Causes of Hashimoto’s Disease
There is no known singular factor on what causes Hashimoto’s disease, but there seems to be a combination of multiple factors causing it. Genetic factors are predominantly responsible, as people with a family history of thyroid problems or other autoimmune diseases seem to be more susceptible to developing the disease.
Gender appears to play a significant role as shown by the statistical evidence, which suggests that Hashimoto’s disease affects more women about seven times in comparison to men. This data goes to show that sex hormones do play a vital role in this type of autoimmune disease. Many women seem to develop thyroid problems during the first year after delivering a baby. Only 20 percent of the cases could develop into Hashimoto’s disease years later, while most cases usually wear off. Although iodine is required in trace amounts to make the thyroid hormone, sometimes, too much of iodine could also trigger a thyroid disease in susceptible people.
Exposure to radiation could also cause thyroid problems. The radiation used in the medical treatment of Hodgkin’s disease, radiation from the atomic bomb in Japan, and the Chernobyl disaster have exposed people to harmful radiation levels. These people have been reported to develop thyroid diseases.
The Symptoms of Hashimoto’s Disease
Hashimoto’s thyroiditis is a mild health condition, which has subtle symptoms. It may take months to years for the disease to progress and for the visible signs to appear. An enlarged thyroid gland, which is called "goiter", is the first sign of the disease. As the disease progresses, there is further enlargement of the thyroid gland, making the neck looking swollen, which hampers swallowing.
Its early symptoms, although suggestive, but non-conclusive, include fatigue, constipation, dry skin, and weight gain. As the disease progresses, one may show very conclusive symptoms such as:
- Cold intolerance
- Hoarseness of one's voice
- Lethargic movements and feeling tired due to the body's slow metabolism
- Slow heart rate
- Decreased sweating
- Peripheral neuropathy
- Mild hearing loss
- Constipation
- Galactorrhea
- Depression
- Dementia
- Psychiatric issues
- Memory loss
- Joint and muscle pain
- Cramps
- Hair loss, hair thinning, or brittle hair
- Fertility problems
- Irregularities in the menstrual cycle or heavy menstrual periods in women
- Sleep apnea
- Daytime somnolence or sleepiness
The symptoms listed above are not conclusive on their own, so clinical tests are still needed to be done to arrive at a proper diagnosis.
Diagnosis of Hashimoto’s Disease
The extent of hypothyroidism and age factor determine the physical presentations of the disease. The physical findings include a puffy face and periorbital edema. Other signs and symptoms include:
- Skin that is rough and scaly to touch
- Peripheral edema of the hands and feet
- Thickened, brittle, and ridged nails
- Diastolic hypertension with a raised blood pressure
- Bradycardia
- Ataxia
- Macroglossia (abnormally large tongue)
- Slow speech
- Reduced deep tendon reflexes
Initial diagnosis can only be based on laboratory tests involving the routine screening of the thyroid function. The thyroid-stimulating hormone (TSH) serum levels are tested to investigate the functioning of the thyroid gland. An increased level of a person's TSH indicates hypothyroidism. If there is an abnormal level of TSH, T3 (triiodothyronine) and T4 (thyroxine) are also measured to know the extent of the thyroid gland's irregularity. If a person's T4 level is low but with a high TSH level, it is indicative of hypothyroidism.
The presence of anti-thyroid peroxidase and antithyroglobulin are also tested to confirm the cause of Hashimoto’s disease. Complications could also arise in a person having Hashimoto’s disease. Thus, a complete blood count to check for anemia is also done along with other tests such as the total and fractionated lipid profiles.
About 30-40 percent of people who have Hashimoto’s disease are anemic. Patients with hypothyroidism often show elevated levels of total cholesterol, LDL, and triglycerides. Tests are conducted to evaluate the basic metabolic panel. Basically, this test helps in checking the irregularities in the glomerular filtration rate. In people with Hashimoto’s disease, the glomerular filtration rates are reduced. Their renal plasma flow is also decreased along with a reduced level of renal free water clearance. People who have Hashimoto’s disease also have elevated levels of creatine kinase (CK). The prolactin levels of these people are also raised.
Treatment for Hashimoto's Thyroiditis
Although there is no cure for Hashimoto’s disease, hormones are replaced with medications that can help regulate the body's hormone levels. This treatment thereby helps in restoring the normal metabolism. The treatment plan and medications are designed to suit varying needs. Several factors determine the dosage, which includes the age and weight of the patient, the severity of the problem, and other health issues that need to be considered. Therefore, dosages may differ from one person having hypothyroidism to another. Levothyroxine sodium is the drug of choice for treating hypothyroidism. It is orally administered and tailored to suit the individuals' needs.
Regular blood tests are done to evaluate the levels of thyroid-stimulating hormones (TSH). The monitoring of TSH results helps in regulating the medications to restore and maintain healthy hormone levels in the body. It may sometimes take a long time to cure the symptoms and for the goiter to disappear. A physical examination should also be routinely conducted, which includes:
- Weight measurement
- Pulse rates
- Blood pressure readings
- Checking for thyroid nodules
In a few cases where a large goiter does not shrink, surgical intervention may be required. Indications for a surgical intervention also include cases wherein a large goiter causes obstructive persistent symptoms such as dysphagia, voice hoarseness, and stridor. A large goiter basically causes an extrinsic obstruction to the airflow.
A cytologic examination can detect the presence of a malignant nodule. Many cases require a "fine needle aspiration," as this procedure can diagnose the presence of a lymphoma. Tumors also need to be surgically removed. Finally, many people will get rid of their goiter due to cosmetic reasons. In many of these cases, the goiters appear to be large and not very aesthetic to look at. This physical deformity necessitates a surgical intervention to get it removed.
