How to determine transient hyperthyroidism

For most people, hyperthyroidism is a chronic disease that causes long-term consumption of the body. However, some people may experience transient hyperthyroidism, which may manifest as excessive and uncontrollable emotions and a rapid increase in hormone levels in the body. In this case, you must go to the hospital for examination and treatment in time to avoid more serious situations and be responsible for your own body. So, how do we determine transient hyperthyroidism?

1. Inspection

Physical examination revealed an enlarged thyroid gland (mild to severe). In elderly patients, the enlargement is often not obvious and the thyroid gland is soft or medium in texture. In severe patients, vascular murmurs can be heard throughout the entire period using a stethoscope. In severe hyperthyroidism, tremors can even be felt when touched by hand. The heart rate of most patients with hyperthyroidism is increased, often exceeding 90 beats per minute when at rest, and elderly patients may exhibit rapid atrial fibrillation. Patients with hyperthyroidism have hot flashes on the skin and fine hand tremors. Many patients also have eyelid edema, widened palpebral fissures, less blinking in both eyes, and conjunctival congestion and edema. Severe patients may experience exophthalmos, restricted eye movement, and even incomplete eyelid closure.

Some patients with more severe hyperthyroidism experience myxedema in the anterior tibia (shinbone) of the lower limbs. The skin in front of the tibia becomes coarser, thicker, and rougher, with an orange peel-like appearance. The sweat hair becomes coarser, similar to elephantiasis, and is quite difficult to treat.

2. Diagnosis

The diagnosis of hyperthyroidism is not difficult. As long as hyperthyroidism is considered, a thyroid function test can be performed to diagnose it.

The secretion of T3, T4, FT3, and FT4 by the thyroid gland is significantly increased, and TSH is often reduced due to the feedback between the thyroid and pituitary axis. If a patient's T3, T4, FT3, and FT4 are elevated while TSH is decreased, it means that the patient has hyperthyroidism.

Since most cases of hyperthyroidism are Graves' disease, an autoimmune disease of the thyroid gland, it is often accompanied by elevated thyroid autoantibodies, thyroglobulin antibodies, and thyroid peroxidase antibodies. Graves' disease patients have thyroid-stimulating immunoglobulin (TSI) produced by thyroid cells, so clinical tests show positive thyroid-stimulating hormone (TSH) receptor antibodies (TRAb).

Some patients with hyperthyroidism may only show elevated T3 and FT3, normal T4 and FT4, but decreased TSH, which we call "T3 hyperthyroidism." "T3 hyperthyroidism" is more common in elderly patients with hyperthyroidism or patients with toxic functional autonomous hot nodules.

3. Differential Diagnosis

There are also some inflammatory hyperthyroidism (or destructive hyperthyroidism) in clinical practice. It is caused by thyroid inflammatory reaction which leads to changes in the permeability of thyroid follicular cell membrane. A large amount of thyroid hormone is released into the blood from the follicular cells, causing a significant increase in thyroid hormone and a decrease in TSH in the blood. The clinical manifestations and biochemical tests are similar to hyperthyroidism. Inflammatory hyperthyroidism includes the hyperthyroidism stage of subacute thyroiditis, the hyperthyroidism stage of painless thyroiditis, the hyperthyroidism stage of postpartum thyroiditis and iodine-induced hyperthyroidism type 2. It is important to differentiate Graves' disease from inflammatory hyperthyroidism because the former requires aggressive treatment, while the latter does not. The biggest difference between the two is the thyroid 131I uptake rate test. The thyroid 131I uptake rate in the former is elevated or normal, while that in the latter is suppressed. In addition, the TRAb of the former is positive, while that of the latter is negative. The former is complicated with thyroid-related eye disease, while that of the latter is not.