Symptoms and Diagnosis of Hyperthyroidism

Symptoms and Complications

1. Symptoms and Signs of Hyperthyroidism

· General symptoms of hyperthyroidism
Thyroid hormones promote the body’s metabolism and continuously consume energy, so people sweat a lot, cannot tolerate heat, and drink a lot of water. Overall fatigue increases, and patients complain of generalized weakness. When thyroid hormone levels rise, appetite increases and food intake goes up, but energy consumption also increases, so weight generally decreases. In older adults, weight may also decrease due to poor appetite. In many patients, the thyroid becomes enlarged, causing a goiter that makes the neck appear swollen overall.

· Neurological symptoms
People become easily excitable, feel anxious, and become irritable. Concentration decreases, work performance declines significantly, and the hands and feet tremble. Sleep is poor, and hypersensitivity may occur.

· Cardiovascular symptoms
The pulse becomes rapid, palpitations occur, and shortness of breath may develop when walking quickly. In some cases, arrhythmia occurs and an irregular heartbeat may be felt.

· Digestive symptoms
When thyroid hormone levels rise, bowel movements increase, and frequent stools or persistent diarrhea may occur.

· Musculoskeletal symptoms
Muscles atrophy and muscle strength weakens; in severe cases, marked myasthenia may occur.

· Skin symptoms
As metabolism increases, body temperature rises, the skin becomes warm and moist, and the palms sweat heavily. Itching that was not present before and hair loss may appear, but in most cases these are temporary phenomena, and when hyperthyroidism improves, they do not progress to permanent hair loss.

· Reproductive symptoms
In women, menstruation becomes irregular and amenorrhea may occur. If hyperthyroidism persists, it may be one cause of infertility. In men, sexual function declines, sperm count decreases, fertility rate declines, and symptoms such as breast enlargement similar to that seen in women may appear.

· Eye symptoms
Some patients have thyroid eye disease. They may feel glare or as if a foreign object has entered the eye, and in severe cases, double vision and exophthalmos, in which the eyes protrude, may occur. If swelling of the eyes becomes severe, the optic nerve may be compressed, and vision loss may occur, though this is rare.

2. Abnormal blood test results
   Thyroid function tests performed with blood tests show abnormal findings with increased thyroid hormone levels. In addition, biochemical tests may show increased fasting blood glucose, liver enzyme levels, and calcium. As hyperthyroidism persists, blood glucose may rise and diabetes may be diagnosed, and in patients who already have diabetes, blood sugar control may become difficult.

3. Other abnormal test results
   Arrhythmias may be observed on an electrocardiogram. Most improve with treatment of hyperthyroidism, but in some older patients, arrhythmias may persist. As the natural processes of bone formation and breakdown increase, bone density decreases, and osteopenia or osteoporosis may be diagnosed.

Diagnosis

1. Diagnosis
   If a physical examination shows the typical symptoms and signs of hyperthyroidism, and blood tests show increased thyroid hormone levels, hyperthyroidism can be easily diagnosed. In particular, if there is thyroid eye disease with eye symptoms, a family history of thyroid disease, or a goiter with an enlarged neck, diagnosis is easy. However, in early hyperthyroidism, when thyroid function changes are not large, it is difficult to identify the condition based on symptoms and signs alone.

Thyroid function tests measure the concentration of thyroid hormones in the blood, and if the test confirms that thyroid hormone levels are increased, hyperthyroidism can be diagnosed.

2. Differential diagnosis
   The clinical symptoms of thyrotoxicosis are similar in many respects to those seen in conditions such as panic attacks, mania, adrenal medullary tumors, and cancers accompanied by weight loss. These conditions are readily distinguished through thyroid function tests (blood tests), and if the test results are normal, hyperthyroidism can be ruled out.

So far, we have explained the symptoms and diagnosis of hyperthyroidism. In the next part, we will look at Treatment of Hyperthyroidism I.

Source: Korea Centers for Disease Control and Prevention, National Health Information Portal