Rising hypothyroidism diagnoses highligh need for regular screening

The number of patients with hypothyroidism has significantly increased in Korea. Hypothyroidism is a condition in which the thyroid gland fails to produce sufficient hormones, resulting in a slow metabolism. According to statistics from the Health Insurance Review and Assessment Service, the number of hypothyroidism patients in Korea has reached nearly 680,000.

Hypothyroidism presents various symptoms, including fatigue, weight gain, and sensitivity to cold, but early detection and hormone replacement therapy can enable patients to lead normal lives. Korea Biomedical Review spoke with Professor Song Kee-ho of the Department of Endocrinology at Konkuk University Medical Center about the causes and treatment of hypothyroidism.

Question: Are the number of hypothyroidism patients increasing?

Answer: Rather than increasing, the aging population is growing, and thyroid function tends to decline gradually with age. The diagnostic criteria themselves differ slightly between younger and older individuals, and since the criteria for younger individuals have remained unchanged, more older adults are being diagnosed.

In addition, thyroid cancer and tumors are being detected more frequently, leading to thyroid removal through surgery, which also causes a lack of hormone production. Recently, many targeted anticancer drugs that suppress thyroid function are being used, which also has an impact.

Q: What are the primary symptoms of hypothyroidism?

A: Thyroid hormones regulate metabolism. When these hormones are deficient, energy metabolism is impaired, leading to sensitivity to cold, dry skin, fatigue, weight gain due to a slowed metabolism, mild memory loss, and constipation. In more severe cases, fluid may accumulate in the heart. In extreme cases, it can lead to myxedema coma, which can cause loss of consciousness.

Q: Isn't it difficult to suspect hypothyroidism based on fatigue alone?

A: The primary cause of fatigue is often psychological issues, such as depression or stress. Cases where fatigue is actually caused by endocrine disorders, such as thyroid or adrenal gland issues, account for less than 10–20 percent of cases. Hypothyroidism should be suspected when fatigue is accompanied by other symptoms, including weight gain and increased sensitivity to cold.

Q: Is hypothyroidism associated with cardiovascular disease?

A: Hypothyroidism causes an increase in LDL cholesterol, the “bad” cholesterol that contributes to atherosclerosis. Weight gain can also increase the risk of cardiovascular disease. In particular, studies have shown that the risk of cardiovascular disease is elevated in patients with subclinical hypothyroidism, which is between normal and hypothyroidism. If hypothyroidism is left untreated, cholesterol levels will continue to rise, increasing the risk of cardiovascular disease.

Q: How do you treat it?

A: Treatment is very simple. You just need to take hormone medication. It is usually taken once a day, first thing in the morning on an empty stomach for better absorption. The half-life of this medication is about a week, so missing a day won’t cause any immediate effects. If you forget to take it, you can take the missed dose the next day. You can take two pills the next day.

Q: Do patients have to take the medication for the rest of their lives?

A: At least for the rest of their lives. The main cause of hypothyroidism is Hashimoto's thyroiditis, an autoimmune disease. Autoimmune diseases do not disappear with medication. The medication supplements the hormones that the thyroid gland cannot produce due to the destruction of thyroid tissue caused by the autoimmune disease, but it does not eliminate the autoimmune disease itself. Since the cause remains and only the deficient hormones are supplemented, you can consider it a lifelong medication. In rare cases, inflammation may improve, allowing the medication to be discontinued; however, this occurs in only about one in ten people.

Q: Is there a way to prevent this disease?

A: Since it is something you are born with, it is congenital and has genetic influences. Environmental factors also play a role, such as a diet high in iodine or a diet rich in kimchi, as in Korea. Since it occurs more frequently in women, the influence of female hormones is also a factor. Early detection and treatment are more important than prevention. These days, thyroid tests are almost always included in health screenings, so you can determine the state of your thyroid with a simple blood test.

Q: What is the main age group for this disease?

A: It is about five times more common in women than in men. The influence of female hormones seems to be much stronger. It seems to increase slightly after the age of 40. Hyperthyroidism occurs more frequently in people in their 20s and 30s, but hypothyroidism tends to occur at an older age.

Q: Do you have messages for patients?

A: Hypothyroidism is a condition that is easy to treat and has a good prognosis. With regular hormone medication, patients can lead a normal life. However, it is important to understand that medication must be taken for life. Early detection through regular health check-ups is the most important step.