Graves’ disease is associated with hyperthyroidism, which can have more or less important effects on the functioning of the cardiovascular, respiratory, muscular, endocrine, and nervous systems.
Definition of Graves’ Disease
Graves’ disease, also known as toxic diffuse goiter or exophthalmic goiter, is characterized by hyperthyroidism.
Hyperthyroidism itself is defined as the excessive production (more than the body needs) of thyroid hormones, which are produced by the thyroid gland. The thyroid gland is an endocrine gland that produces hormones that are essential for the regulation of various bodily functions. It is located at the front of the neck, below the larynx.
The thyroid gland produces two main hormones: triiodothyronine (T3) and thyroxine (T4). The first is produced from the second. Triiodothyronine is also the hormone that is most involved in the development of many tissues in the body. These hormones circulate through the body via the blood network. They are then distributed to the target tissues and cells.
Thyroid hormones are involved in metabolism (a series of biochemical reactions that enable the body to maintain a state of balance). Thyroid hormones are also involved in brain development and also in the functioning of the respiratory, cardiac, and nervous systems. These hormones also regulate body temperature, muscle tone, menstrual cycles, weight, and cholesterol levels. In this sense, hyperthyroidism then leads to more or less important dysfunctions within these different body functions.
These thyroid hormones are in turn regulated by another hormone: the thyroid-stimulating hormone (TSH). TSH is produced by the pituitary gland (an endocrine gland in the brain). When the level of thyroid hormone in the blood is too low, the pituitary gland releases more TSH. On the contrary, when the level of thyroid hormones is too high, the endocrine gland in the brain reacts and reduces the release of TSH.
In connection with pregnancy, hyperthyroidism can have more serious consequences for mother and child. It can lead to miscarriages, premature births, fetal malformations, and functional issues in the child. In this sense, these sick pregnant women should be closely monitored.
Causes of Graves’ Disease
Graves’ disease is an autoimmune hyperthyroidism. It is a pathology caused by a dysfunctional immune system. This is mainly due to a circulation of antibodies that are able to stimulate the thyroid gland. These antibodies are called thyrotropin receptor antibodies.
The diagnosis of this pathology is made when the thyrotropin receptor antibodies test is positive.
The therapeutic treatment of this disease depends directly on the level of thyrotropin receptor antibodies measured in the blood.
Other antibodies may also be involved in the development of Graves’ disease. These affect between 30 % and 50 % of the patient cases.
Who is affected by Graves’ disease?
Graves’ disease can affect all individuals. Young women between 20 and 30 years of age are most affected by the disease. Graves’ disease occurs 5 to 10 times more frequently in women than in men and more frequently between the ages of 40 and 60.
Graves’ Disease: symptoms
The symptoms of Graves’ syndrome are associated with hyperthyroidism:
- Great physical and mental fatigue
- Nervousness and anxiety
- Sleep disorders
- Weight loss, despite increased appetite
- Frequent bowel movements
- Tremor of the extremities
- Excessive sweating
- Heat intolerance
- Polydipsia (excessive thirst)
- Goiter of the thyroid gland
- Bulging Eyes (exophthalmos), sometimes with irritation of the eyelids
In a more advanced stage, Graves’ disease leads to amyotrophic muscle weakness. The complications are mainly heart-related (heart failure, ventricular fibrillation).
In the case a patient has bulging eyes other clinical signs can be identified: burning eyes, swelling of the eyelids, watery eyes, increased sensitivity to light, eye pain, and others.
In addition to the above symptoms a diagnosis could be complemented with an ultrasound and a CT scan.
Treatments for Graves’ disease
The primary diagnosis is clinical and visual. The next phase is the performance of additional medical examinations (CT, ultrasound, etc.) as well as biological tests. The latter results in the analysis of the TSH level in the blood and the thyroid hormones T3 and T4. These biological tests make it possible in particular to assess the severity of the disease.
Initially, treatment is carried out with medication. This includes the prescription of Carbimazole for an average period of 18 months. This treatment varies according to the T3 and T4 levels in the blood and must be checked once a week. This medicine may cause side effects such as fever or the development of angina pectoris.
In the second phase, in the most extreme cases, the treatment is then surgical. This operation consists of the following:
- Partial or total destruction of the thyroid gland by ingestion of radioactive iodine131
- Partial or total removal (a thyroidectomy) of the thyroid gland (only in large recurrent goiters)
The last two options require the use of thyroid hormones throughout life.
As for the Graves’ exophthalmos, it is treated with steroids in case of acute inflammation of the eyes.