Hypothyroidism: Symptoms, Diagnosis, and Treatment Methods

What is the Thyroid Gland and What Does It Do?

The thyroid gland is an important gland located in the front of the neck that regulates the body's metabolism. It is shaped like a butterfly and consists of two lobes connected by a thin section called the isthmus. It is usually situated just below the larynx (voice box).

The thyroid gland produces thyroid hormones called triiodothyronine (T3) and thyroxine (T4). These hormones regulate cellular energy production, control body temperature, regulate heart rate, affect digestive system activities, and play a role in overall growth and development processes.

Maintaining a balance in thyroid gland functions is crucial. Proper secretion of thyroid hormones affects metabolism, energy levels, body temperature, and the functions of many organs and systems. Problems related to the thyroid gland can lead to an insufficient or excessive production of thyroid hormones. Hypothyroidism refers to the condition where thyroid hormones are produced inadequately, while hyperthyroidism refers to the condition where thyroid hormones are overproduced.

What is Hypothyroidism?

Hypothyroidism is the condition in which the thyroid gland fails to produce a sufficient amount of thyroid hormone.

Hypothyroidism usually occurs due to a decreased function of the thyroid gland. The most common cause is an autoimmune thyroiditis called Hashimoto's thyroiditis, where the immune system mistakenly attacks the thyroid tissue, causing inflammation and reduced production of thyroid hormone.

What Are the Causes of Hypothyroidism?

There are various factors that can cause hypothyroidism. Here are common factors that can lead to hypothyroidism:

- Autoimmune thyroiditis (Hashimoto's thyroiditis): This is the most common cause of hypothyroidism. The immune system mistakenly attacks the thyroid gland, causing inflammation. In this condition, the thyroid tissue becomes damaged, leading to reduced production of thyroid hormone.

- Thyroid surgery or radiotherapy: When the thyroid gland is surgically removed or when radiotherapy (high-dose radiation therapy) is administered, the function of the thyroid gland is diminished or completely halted.

- Iodine deficiency: Iodine is an essential component of thyroid hormones. Insufficient iodine levels in the body can affect the production of thyroid hormones.

- Congenital hypothyroidism: It is the condition where the thyroid gland fails to function adequately in babies before or immediately after birth. This condition is usually present from birth and requires timely diagnosis and treatment.

- Medications: Some medications can affect the function of the thyroid gland. For example, certain antithyroid medications are used in the treatment of hyperthyroidism, while some drugs can reduce the production of thyroid hormones.

- Radioactive iodine treatment: In cases of overactive thyroid gland (hyperthyroidism), radioactive iodine treatment may be administered. This treatment damages thyroid cells, reducing the production of thyroid hormone and sometimes leading to hypothyroidism.

- Other causes: Infections of the thyroid gland, inflammatory diseases, certain genetic disorders, trauma to the thyroid gland, or other conditions that affect thyroid hormone production can also cause hypothyroidism.

What are the symptoms of hypothyroidism?

The symptoms of hypothyroidism can vary from person to person and may sometimes be subtle. Below are some common symptoms of hypothyroidism:

- Fatigue and lack of energy: Feeling constantly tired, a decrease in energy levels, and weakness are common symptoms of hypothyroidism.

- Feeling overweight or weight gain: Due to a slower metabolism, weight gain or difficulty losing weight may be observed.

- Depression or low mood: Hypothyroidism can have negative effects on mood and can lead to depression, anxiety, irritability, and other emotional changes.

- Forgetfulness and difficulty concentrating: Low thyroid hormones can affect cognitive functions and can cause problems with focus, memory, and mental clarity.

- Constipation: Low levels of thyroid hormones can slow down bowel movements and lead to constipation.

- Cold intolerance: Due to a decrease in body temperature and a slower metabolism, individuals with hypothyroidism may be more sensitive to cold.

- Hair loss: Hair may become dull, brittle, and thinning or experience hair loss.

- Dry skin: Low levels of thyroid hormones can cause moisture loss in the skin and lead to dry, flaky skin.

- Menstrual irregularities: In women, hypothyroidism can cause disruptions in the menstrual cycle, irregular or heavy periods, and fertility problems.

- Muscle aches and joint stiffness: Hypothyroidism can lead to muscle aches, weakness, and joint stiffness.

These symptoms are generally common in hypothyroidism but can vary in each individual. If you suspect hypothyroidism or have these symptoms, it is important to be evaluated by an internal medicine specialist or an endocrinologist.

How is hypothyroidism diagnosed?

The diagnosis of hypothyroidism is typically made by an internal medicine specialist or an endocrinologist. The diagnosis may involve the following steps:

- Taking the patient's history: The doctor evaluates the patient's symptoms, family history of thyroid disease, medication use, past or current medical conditions, and other relevant information.

- Physical examination: The doctor measures the patient's height, weight, checks the pulse, blood pressure, and evaluates the thyroid gland by palpation. Possible findings such as hypothyroidism symptoms or enlargement of the thyroid gland are investigated.

- Blood tests: Blood tests are conducted to measure the levels of thyroid hormones. Typically, the level of thyroid-stimulating hormone (TSH) is measured. In hypothyroidism, TSH levels are usually high, and free thyroxine (FT4) levels are low. In some cases, triiodothyronine (T3) levels may also be checked.

- Imaging tests: In some cases, imaging tests such as ultrasound or thyroid scintigraphy may be performed to assess the structure and size of the thyroid gland.

- Additional tests: In certain cases, additional tests such as thyroid antibodies may be conducted. These tests can help detect autoimmune thyroiditis or other thyroid disorders.

The diagnosis of hypothyroidism is made based on symptoms, physical examination findings, and laboratory test results. It is important to have an accurate diagnosis and regularly monitor thyroid function to determine the appropriate treatment plan. Therefore, if you experience hypothyroidism symptoms, it is important to consult a healthcare professional and discuss the necessary tests with them.

What are the Treatment Methods for Hypothyroidism?

The treatment of hypothyroidism is typically done through synthetic thyroid hormone supplementation. The most commonly used thyroid hormone medication is called levothyroxine. Levothyroxine is used to replace the deficient thyroid hormone and ensure proper functioning of the metabolism.

The dosage of levothyroxine for hypothyroidism treatment is determined based on factors such as the patient's age, weight, thyroid hormone levels, and other health conditions. After starting the treatment, regular blood tests are conducted, and the dosage of levothyroxine is adjusted. The goal is to bring thyroid hormone levels back to normal and alleviate symptoms.

Levothyroxine is usually taken on an empty stomach in the morning and should not be taken with other medications or food, as it can affect its absorption. It is important to have regular doctor check-ups during the treatment. The doctor can adjust the dosage of levothyroxine and monitor thyroid hormone levels.

Hypothyroidism treatment generally continues for a lifetime. Regular intake of the medication helps maintain balanced thyroid hormone levels and assists in keeping symptoms under control. Adhering to the treatment is crucial because neglecting it can lead to the return of symptoms and an increased risk of complications.

In some cases, the underlying cause of hypothyroidism can be treated or corrected. For example, if iodine deficiency is causing hypothyroidism, iodine supplementation can be given. If surgical removal of the thyroid gland is necessary, levothyroxine treatment will be lifelong.

The treatment of hypothyroidism requires an individualized approach. The treatment plan is determined by the doctor based on the patient's condition, symptoms, and laboratory results. Therefore, it is important to maintain regular communication with an internal medicine specialist when diagnosed with hypothyroidism.