3 Top Causes for Hypothyroidism

3 Top Causes for Hypothyroidism
Hypothyroidism is a condition in which the body does not produce enough thyroid hormones. (Shutterstock)
Camille Su
11/26/2022
Updated:
3/22/2023
Some people visit several hospitals to see doctors from different departments because of symptoms such as fatigue, joint and muscle pain, constipation, swelling, etc., and it is not until the end that they discover the real culprit: hypothyroidism.
The thyroid is an endocrine organ that has a major impact on the metabolism of the whole body. Do we need to take medicine for life if we suffer from hypothyroidism?

Hypothyroidism Has Many Symptoms

The thyroid is a butterfly-shaped organ on the front of the neck that secretes thyroxine, which controls many important bodily functions. Levels of thyroxine can affect breathing, heart rate, weight, and mood. Many body functions will slow down without enough thyroxine. The disease caused by insufficient secretion of thyroxine is called hypothyroidism.
Symptoms of hypothyroidism vary from person to person and may include: fatigue, cold intolerance, constipation, low voice, slow reflexes, dry skin, thinning hair, body puffiness, weight gain, slow heartbeat, joint and muscle pain, memory loss, and depression. 
Women can also face problems like irregular menstruation, heavy menstrual bleeding, and infertility.
Yilun Chiang, the chief physician of the Department of Endocrinology at Shin Kong Wu Ho-Su Memorial Hospital in Taiwan, said that blood tests for such patients may also detect hyponatremia, anemia, or elevated LDL cholesterol.
Due to the variety of symptoms of hypothyroidism, many patients often discover that they have this disease after undergoing multiple different examinations.
Chih-Yuan Wang, deputy director of the Internal Medicine Department of National Taiwan University Hospital, pointed out that the most common symptom is fatigue. However, fatigue is a non-specific symptom. Anemia, poor sleep quality, or getting older can also make a person tired easily. Therefore, many people will not suspect that they have a thyroid problem.
A patient’s body weight may increase slightly or significantly as thyroxine deficiency worsens because poor metabolism will increase body fat.
In addition, Chih-Yuan Wang said that some patients look swollen, but it is not edema, but myxedema. Its characteristic is that there will be no pit in the swollen area when pressed with fingers. Myxedema is caused by a lack of thyroxine. This causes the fibroblasts of the connective tissue in the body to produce too many mucopolysaccharides similar to hyaluronic acid; it deposits in the dermis, scar tissue, or internal organs, resulting in a swollen appearance.
As the condition progresses, patients will show symptoms of cold intolerance, slow heartbeat, and slow reflexes. If left untreated, patients may develop pleural and pericardial effusions. In the most severe cases, it can develop into a myxedema coma, with symptoms including hypoventilation, hypothermia, low blood pressure, slow heartbeat, and confusion.
Yilun Chiang suggested that if you experience fatigue, constipation, swollen appearance, and cold intolerance, you can go to the Department of Endocrinology and Metabolism for examination.

Causes of Hypothyroidism

According to Chih-Yuan Wang, there are three common causes of hypothyroidism in adults:

1. Autoimmunity

Autoimmunity, in which your own immune system attacks itself, is the most common cause of hypothyroidism. The patient’s immune system will attack the thyroid gland, causing it to become inflamed and unable to secrete enough thyroxine.
For people with a family history of autoimmune thyroid disease, it is recommended to reduce the intake of foods with high iodine content; it may prevent the onset of the disease.

2. Surgery and radiation therapy

Hypothyroidism may result from insufficient thyroid tissue remaining after surgical treatment for diseases such as thyroid cancer, hyperthyroidism, and thyroid nodules.
Radiation therapy used to treat head and neck cancers can also affect the thyroid gland, causing it to become underactive.

3. Aging

Chih-Yuan Wang said that foreign studies have found that people over the age of 55 are more likely to suffer from the disease.
There is a higher proportion of women among patients with hypothyroidism. Goiter, thyroid dysfunction, and autoimmune thyroid disease are all more common in women. However, the ratio of male to female prevalence is similar in the elderly population.

Does Hypothyroidism Require Lifetime Medication?

When a doctor suspects that a patient has hypothyroidism, blood tests are done to evaluate the thyroid function to confirm whether it is an underactive thyroid. Sometimes, thyroid antibodies are further tested, and a thyroid ultrasound is conducted to evaluate whether the thyroid structure is normal. This is done to understand the possible causes of hypothyroidism.
If it is confirmed to be hypothyroidism, most patients need to take thyroxine medication for the rest of their lives.
However, this is usually difficult to accept for patients who are not mentally prepared to take medicine for a lifetime. “So, when we find that the patient has hypothyroidism, we should not rush to give the patient medicine,” Chih-Yuan Wang said.
Generally, doctors will conduct blood tests again after a certain period of time to confirm whether the patient really has hypothyroidism. It is necessary to see whether the blood test report and other clinical evidence support life-long treatment, said Chih-Yuan Wang. At the same time, they must also prescribe different treatment models according to the patient’s ethnic group, age, symptoms, lifestyle, and whether they have autoimmune diseases.
Patients who have undergone thyroid surgery require close monitoring for the development of true hypothyroidism due to tissue loss.
For people over the age of 70, if the blood test report shows mild hypothyroidism and the symptoms are not obvious, it is considered subclinical hypothyroidism. If these patients have not undergone thyroid surgery and have no medical history, it is regarded as a normal aging process. These patients do not need to take medicine right away and are advised to return to the clinic to draw blood for observation.
Chih-Yuan Wang explained that the thyroid gland is an organ affected by stress, and the secretion of thyroxine is controlled by the thyroid-stimulating hormone (TSH) secreted by the pituitary gland. The hormone changes of the pituitary gland change every few hours, so it is impossible to determine whether a patient has hypothyroidism after just one blood test.
For subclinical patients, after adjusting emotions, stress, and especially sleep, the thyroid function can return to a relatively stable and normal range in a short period of time without taking medicine.
Chih-Yuan Wang pointed out that according to statistics, some people already have mild hypothyroidism in their 50s. About 60 to 80 percent of such patients can return to normal within one year through observation and control. “So, most of the time, don’t rush to take medicine, but observe first, as observation itself is a kind of treatment,” he said. During the observation period, maintain a normal schedule, sleep well, and reduce unnecessary stress, such as participating in extreme sports that challenge your ability.
On the contrary, medication is required if the value reported by the blood test is serious and confirmed by at least two blood draws at different times. For example, if the blood test report clearly shows hypothyroidism, and the patient has symptoms of extreme fatigue, hyperlipidemia, and risk of cardiovascular disease, it is necessary to supplement thyroxine. Yilun Chiang said that elderly patients or patients with heart disease generally start with a low dose and then increase it slowly.
People under the age of 70, especially those aged 50 to 60, are more likely to need medication. Chih-Yuan Wang pointed out that past research and analysis of Taiwan’s health examination database found that people in this age group with mild hypothyroidism had an increased mortality rate within eight years, and the cause of death was mostly related to cardiovascular disease.
A 2017 meta-analysis of more than one million people found that compared with euthyroidism, patients with hypothyroidism have a higher risk of cardiovascular disease: 13 percent higher risk of ischemic heart disease, 15 percent higher risk of myocardial infarction, 96 percent higher risk of cardiac mortality, and a 25 percent higher risk of all-cause mortality.
Besides, cardiac patients with hypothyroidism have a 122 percent increased risk of cardiac mortality and a 51 percent increased risk of all-cause mortality; both risks are higher.
Others do not need to take medication for life. Yilun Chiang said that some patients’ hypothyroidism is caused by subacute thyroiditis. Since the thyroid function may slowly return, taking thyroxine temporarily is sufficient. Subacute thyroiditis, a non-persistent and naturally reversible inflammation of the thyroid gland, usually occurs after a cold. Subacute thyroiditis usually occurs after a cold; it is a non-persistent and naturally reversible inflammation of the thyroid gland.
Do patients need to limit iodine intake? Patients with autoimmune antibodies, regardless of their age, should avoid eating high-iodine foods such as nori, kelp, and seaweed in their daily lives, as these foods will aggravate thyroid inflammation and make the condition worse. They should not even consume kelp soup or seaweed soup. At the same time, developing a healthy daily routine, having proper stress relief, and learning to control emotions can all help in managing the condition.
Camille Su is a health reporter covering disease, nutrition, and investigative topics. Have a tip? [email protected]
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