Understanding the Causes, Symptoms, and Treatments of Hashimoto’s Thyroiditis

Hashimoto's thyroiditis is an autoimmune disease affecting the thyroid gland, which is located in the lower part of the neck, just beneath the Adam's apple. The thyroid produces hormones that assist in regulating numerous bodily functions.

In the majority of cases of Hashimoto's thyroiditis, the thyroid does not produce enough triiodothyronine (T3) and thyroxine (T4) hormones for the body, leading to a decrease in metabolism.

This article outlines details on Hashimoto’s thyroiditis, from symptoms and diagnosis to treatment options.

Causes of Hashimoto’s Thyroiditis

While researchers have not determined the exact reasons why some individuals develop Hashimoto’s thyroiditis, a family history of thyroid conditions is often noted. Several factors are possibly involved, including:

• Genetic factors
• Viruses, such as hepatitis C
• Environmental influences, like infections, stress, or exposure to radiation
• Certain medications prescribed for bipolar disorder or other mental health issues
• Iodine-based medications used for irregular heart rhythms
• Exposure to harmful substances, such as nuclear radiation

Who is at Risk of Developing Hashimoto’s Thyroiditis?

The following factors are associated with increased susceptibility to Hashimoto's thyroiditis:

• Gender: There is a strong predisposition of women being diagnosed with Hashimoto's Thyroiditis.
• Age: This condition can manifest at any age but the majority of patients are between the ages of 40 and 60 years.
• Other Autoimmune Diseases: A history of another autoimmune disease can increase one's risk of Hashimoto's thyroiditis, including conditions like rheumatoid arthritis, type 1 diabetes, and lupus.
• Family History and Genetics:  Having first-degree relatives with thyroiditis or any other thyroid diseases may raise the possibility of having Hashimoto's thyroiditis.
• Pregnancy:  Normal shifts in immune response during pregnancy might contribute to the onset of Hashimoto's thyroiditis post-pregnancy.
• Excessive Iodine Consumption:  A high intake of iodine in the diet may serve as a trigger for those already predisposed to Hashimoto's thyroiditis.
• Radiation Exposure: Individuals with a high degree of exposure to environmental radiation are at higher risk for developing Hashimoto's thyroiditis.

Recognising the Signs of Hashimoto’s Thyroiditis

Hashimoto's thyroiditis can initially present with no symptoms, and many individuals remain undiagnosed for years. Over time, as the condition progresses, the thyroid gland is damaged, leading to a decrease in thyroid hormone production, which results in hypothyroidism. 

Some common symptoms of hypothyroidism include:

• Tiredness
• Swelling of the thyroid (goitre)
• Increased weight
• Difficulty handling cold temperatures
• Dry skin or thinning, brittle hair
• Pain in joints and muscles
• Mood disturbances such as depression
• Constipation
• Heavy or irregular menstrual cycles or issues with fertility
• Reduced heart rate
• Joint pain and stiffness
• Irregular or heavy menstrual bleeding
• Memory or concentration difficulties
• A swollen face
• Brittle nails

Possible Complications of Hashimoto's Thyroiditis

If Hashimoto's thyroiditis remains untreated, you might encounter the following complications:

• Goitre: Your neck may appear as if there’s a tennis ball lodged within it due to the swelling of your thyroid gland.
  Cardiac Problems: Insufficient levels of thyroid hormones can lead to elevated levels of Low-Density Lipoprotein (bad) cholesterol, heightening the risk of heart-related Thyroiditis.
• Mental Health Issues: This may include feelings of depression.
• Sexual Dysfunction: This can result in reduced libido, inability to ovulate, erectile dysfunction, or a low sperm count.
• Pregnancy Complications: If a woman with untreated Hashimoto's is pregnant, the chances of experiencing a miscarriage or premature delivery increase.
• Myxedema: In extremely rare but severe cases, if the body is exposed to colds, infections, or sedatives, the chances of myxedema coma increase.

Pathophysiology: How Hashimoto's Thyroiditis Affects the Body

Hashimoto’s disease is believed to have an autoimmune origin, and its characteristic symptoms include fibrosis and lymphocyte infiltration. Clinical symptoms that match laboratory findings of increased TSH with normal to low thyroxine levels are the basis of the diagnosis.

Anti-TPO (Thyroid Peroxidase) antibodies have been demonstrated to bind and destroy thyrocytes in vitro and activate the complement system. However, there is currently no evidence that the concentration of anti-TPO antibodies in serum correlates with the disease's severity.

Diagnosis of Hashimoto’s Thyroiditis

Healthcare providers diagnose Hashimoto's thyroiditis through:

Medical History and Physical Examination

Physicians usually begin by gathering medical history and conducting a physical examination. Along with inquiring about symptoms, the doctor palpates the neck for any signs of goitre, which some individuals with Hashimoto's thyroiditis may develop.

Blood Tests

To diagnose Hashimoto's thyroiditis and hypothyroidism, blood tests typically measure thyroid hormones like triiodothyronine (T3) and thyroxine (T4), thyroid-stimulating hormone (TSH), and thyroid peroxidase antibodies (TPO), which are commonly elevated in the condition​.

Other Tests

Additional tests are usually unnecessary to confirm Hashimoto's thyroiditis. However, if antithyroid antibodies are not present in the blood, an ultrasound may be recommended to assess the thyroid's size and characteristics. The ultrasound can also help rule out other causes of an enlarged thyroid, such as thyroid nodules.

Treatment Options for Hashimoto’s Thyroiditis

The treatment for Hashimoto's thyroiditis varies based on the extent of damage to the thyroid gland and whether it has led to hypothyroidism. If hypothyroidism is mild or absent, medication may not be prescribed, and symptoms and thyroid hormone levels will be monitored.

If hypothyroidism is present, levothyroxine, a synthetic version of thyroid hormone T4, will be prescribed in pill, gel capsule, or liquid form to restore metabolic function. The dosage will be adjusted based on thyroid function tests, typically conducted six to eight weeks after starting treatment and monitored annually thereafter.

Management and Monitoring

Not everyone with Hashimoto’s thyroiditis presents with the symptoms of the disease. If one has high antibody levels but does not have clinical hypothyroidism, the healthcare provider is likely to monitor the thyroid levels instead of beginning treatment. In case Hashimoto’s disease leads to hypothyroidism, levothyroxine is often the go-to medication that is prescribed.

The Role of Diet and Lifestyle in Managing Hashimoto’s Thyroiditis

The thyroid gland utilises iodine, a mineral found in certain foods, to produce thyroid hormones. However, for those with Hashimoto’s thyroiditis or other autoimmune thyroid disorders, there may be a sensitivity to adverse effects caused by iodine.

Consuming foods high in iodine, such as kelp, dulse, and various other types of seaweeds, as well as certain iodine-rich medications, can potentially exacerbate hypothyroidism. Additionally, taking iodine supplements may lead to better management.

Prognosis and Long-term Outlook

With proper treatment, the prognosis for Hashimoto’s thyroiditis is pretty excellent. Treatment with synthetic drugs such as levothyroxine does not cure the disease but helps with the management and maintenance of the thyroid levels. One’s healthcare provider will likely recommend regular blood tests to monitor thyroid hormone levels.
Overall, with regular follow-ups and treatment, patients diagnosed with Hashimoto’s thyroiditis can lead long, healthy lives.

Conclusion

Hashimoto’s thyroiditis is a condition that can be managed effectively. If symptoms related to Hashimoto’s are present, or if there are risk factors such as a family history of thyroid disorders, it is important to consult a healthcare provider. They can perform simple tests to assess thyroid function and recommend tailored solutions.