Hashimoto: What It Is, Causes, Symptoms, and Treatment

Hashimoto's disease is a condition that affects the thyroid gland. This disease, also known as Hashimoto's thyroiditis, causes the thyroid gland to become underactive.

What is Hashimoto's Disease?

Hashimoto's disease is an autoimmune condition that leads to an underactive thyroid, or hypothyroidism. It is the most common cause of hypothyroidism.

The thyroid is a butterfly-shaped organ located at the front of the neck. The thyroid glands are responsible for synthesizing thyroid hormones, and these glands are part of the endocrine system.

Thyroid hormones affect metabolism in the body. When these hormones are not produced in sufficient amounts, it can lead to issues such as irregular heart rhythm, problems with calorie burning, and many other complications.

What Are the Symptoms of Hashimoto's Disease?

In the early stages, there may be no symptoms or signs, but some patients may experience enlargement of the thyroid gland. This enlargement occurs at the front of the neck, just below the Adam's apple.

Hashimoto's disease develops slowly over the years and leads to chronic damage in the thyroid tissue. The main cause is the body's immune system recognizing the thyroid gland as foreign tissue and trying to destroy it. This is done through substances called antibodies, which the body produces against the thyroid gland. Damaged thyroid tissue is unable to synthesize enough hormones. As a result, the levels of thyroid hormone in the blood drop, leading to a condition called hypothyroidism, which causes various symptoms throughout the body.

Symptoms of Hypothyroidism

• Fatigue, sluggishness
• Sensitivity to cold, feeling very cold
• Constipation
• Pale, dry skin
• Swollen, puffy face
• Brittle nails
• Hair loss
• Enlargement of the tongue
• Unexplained weight gain
• Muscle pain, tenderness, and stiffness
• Joint pain and stiffness
• Muscle weakness
• Heavy or prolonged menstrual periods
• Depression
• Memory problems

What Causes Hashimoto's Disease?

Hashimoto's disease is an autoimmune disorder. In Hashimoto's disease, the patient's immune system produces antibodies against the thyroid gland, which it normally produces to target foreign tissues in the body. The exact reason why the immune system recognizes the thyroid gland as foreign and produces antibodies against it has not been fully clarified. However, it is believed that both genetic and environmental factors play a role in the development of the disease.

There are certain risk factors for Hashimoto's disease, including:

• Gender: Hashimoto's disease is more common in women than in men.
• Age: While Hashimoto's thyroiditis can affect people of all ages, it is more commonly seen in middle-aged individuals.
• Genetics: Individuals with a family history of Hashimoto's disease or other autoimmune diseases have an increased risk of developing Hashimoto's thyroiditis.
• Radiation Exposure: Individuals exposed to high levels of environmental radiation have a higher risk of developing Hashimoto's disease.

How is Hashimoto's Diagnosed?

Individuals who present with symptoms such as dry skin, constipation, excessive fatigue, or hoarseness may be evaluated for Hashimoto's disease.

In diagnosing Hashimoto's disease, the patient's symptoms and signs are very important. If the symptoms suggest Hashimoto's thyroiditis, a blood test is performed. The blood test measures the levels of thyroid hormones and TSH (Thyroid Stimulating Hormone), which is produced by the pituitary gland and stimulates the thyroid. Several tests can be used to diagnose Hashimoto's disease:

• Hormone Test: This test measures both thyroid hormone levels and TSH concentration in the blood. If the thyroid is underactive, thyroid hormone levels will be low. TSH increases to stimulate the thyroid to produce more hormones.
• Antibody Test: Since Hashimoto's is an autoimmune disease, abnormal antibodies are produced. The thyroid peroxidase (TPO) enzyme, which normally plays a role in hormone production in the thyroid, is targeted by these antibodies in Hashimoto's. Anti-Tg antibodies may also be present. These antibodies can be detected through blood tests. However, it should be noted that not every patient with Hashimoto's will test positive for these antibodies, and not everyone with a positive test shows symptoms of Hashimoto's.
  The most common method used in diagnosing Hashimoto's is the hormone test, which measures thyroid hormones and TSH levels. This test is also used for medication dosage adjustments and monitoring during treatment.

Symptoms Associated with Hashimoto's Disease

If left untreated, Hashimoto's disease can lead to various health complications, including:

• Goiter: The thyroid gland becomes overstimulated to compensate for its underactivity, leading to enlargement, known as a goiter. While goiter usually does not cause significant problems, it can be uncomfortable for some individuals. Extremely large goiters may make swallowing and breathing difficult.
• Heart Problems: Hypothyroidism can increase "bad" cholesterol (LDL) levels, which may increase the risk of heart disease. Untreated Hashimoto's can also lead to heart enlargement and heart failure.
• Mental Health Issues: Depression seen in Hashimoto's disease can worsen over time. Hashimoto's can also slow mental functions, and it can reduce libido in both men and women.
• Myxedema: Untreated Hashimoto's disease may cause myxedema, a severe and life-threatening condition that can lead to mental status changes, ranging from sluggishness to loss of consciousness. Myxedema can be triggered by cold exposure, sedative medications, infections, and other stress-inducing situations. It requires immediate medical intervention, and it is typically seen in older individuals with serious respiratory and cardiovascular conditions.
• Birth Defects: Babies born to mothers with untreated hypothyroidism are more likely to have birth defects, such as cleft palate. These babies are also at higher risk of developmental delays and mental disabilities. Pregnancy during hypothyroidism can lead to anomalies affecting the brain, heart, and kidneys. Therefore, women planning to become pregnant should have their thyroid hormone levels tested.

How is Hashimoto's Treated?

Treatment for Hashimoto's disease focuses on normalizing thyroid hormone levels. Patients are regularly monitored to track hormone levels.

Hashimoto's treatment typically continues for life.

Patients with thyroid hormone deficiencies receive synthetic (artificial) thyroid hormone. Levothyroxine is commonly prescribed, which is a chemical substitute for the thyroid hormone thyroxine. With regular use of levothyroxine, symptoms of hypothyroidism can be alleviated.

To adjust the levothyroxine dosage, the patient's TSH levels are checked 6-8 weeks after starting treatment. This process is repeated after each dosage change. Once the correct dose is found to normalize thyroid hormone levels, patients only need to visit the doctor annually. Overuse of levothyroxine can lead to health problems like osteoporosis and arrhythmias, so proper dosage is crucial.

For patients with coronary heart disease and severe hypothyroidism, starting hormone treatment with high doses may overwhelm the body's metabolic needs. In these cases, small doses should be used initially.

When used in the correct dosage, levothyroxine generally does not cause side effects. However, it is important to take the medication regularly and not miss doses for it to be effective.

Hashimoto's disease can cause a wide range of symptoms and health issues. If left untreated, it can lead to serious complications. Therefore, individuals who suspect they may have hypothyroidism should seek medical advice and undergo the necessary tests.