Graves' disease is a chronic autoimmune disease that affects the thyroid gland, a small butterfly-shaped gland located in the neck. In a person with Graves' disease, the immune system produces antibodies called thyroid-stimulating immunoglobulin G (TRAb) that bind to the receptors on thyroid cells.
These antibodies trigger an overproduction of thyroid hormones, known as hyperthyroidism. The thyroid hormones, triiodothyronine (T3) and thyroxine (T4), regulate the body's metabolism, so an excess of these hormones speeds up most bodily functions.
The continuous overstimulation of the thyroid gland leads to a series of changes and symptoms characteristic of Graves' disease. These may include increased metabolic activity, unexplained weight loss, irritability, nervousness, heat intolerance, excessive sweating, tremors, insomnia, muscle weakness, increased heart rate, and in some cases, goiter (enlargement of the thyroid gland).
In addition to thyroid-related symptoms, Graves' disease can also manifest with ocular complications, known as Graves' ophthalmopathy. These may include bulging eyes, dry eyes, irritation, double vision, and redness. Not all patients with Graves' disease experience eye problems, but when they occur, they can significantly affect the quality of life.
Graves' disease is an autoimmune disease in which antibodies produced by the immune system stimulate the thyroid gland to produce and release excessive amounts of thyroid hormones. This results in hyperthyroidism and a wide range of symptoms and metabolic changes in the body.
Possible Causes and Risk Factors
The exact causes of Graves' disease are not yet fully understood, but it is believed to be the result of a combination of genetic and environmental factors. Here is a description of possible causes and associated risk factors:
Genetic predisposition:
There is a clear genetic predisposition to Graves' disease. It has been observed that individuals with a family history of the disease have a higher risk of developing it. Certain genes, such as the human leukocyte antigen (HLA) gene, have been identified to be associated with an increased risk of developing the disease.
Environmental factors:
It is believed that triggering environmental factors may play a significant role in the development of Graves' disease in individuals with a genetic predisposition. Some possible environmental triggers include viral or bacterial infections, exposure to certain medications, and emotional stress.
Female sex:
Graves' disease more commonly affects women than men. In fact, women are up to 8 times more likely to develop the disease than men. The exact reason for this gender difference is not fully understood, but it is believed that female sex hormones and genetic factors may play a role in this disparity.
Age:
It typically develops in young and middle-aged adults, usually between the ages of 30 and 50. However, it can affect individuals of any age, including children and teenagers.
Emotional stress:
Chronic or traumatic emotional stress has been associated with an increased risk of developing Graves' disease. It is believed that stress can trigger an abnormal immune response, which may contribute to the development of the disease in genetically susceptible individuals.
Smoking:
Cigarette smoking has been identified as a risk factor for the development of Graves' disease. Studies have shown that smokers have a higher risk of developing the disease and may also have a more severe course of the disease compared to non-smokers.
Symptoms of Graves' Disease
Graves' disease is characterized by a variety of symptoms that can affect different systems of the body. These symptoms are related to hyperthyroidism and the effects of thyroid-stimulating antibodies. Below are some of the most common symptoms of Graves' disease:
1. Hyperthyroidism: The overproduction of thyroid hormones leads to an increase in the body's metabolism, which can cause the following symptoms:
- Unexplained weight loss, despite having a normal or increased appetite.
- Increased sweating and sensitivity to heat.
- Increased heart rate (tachycardia) and palpitations.
- Nervousness, anxiety, and irritability.
- Tremors in the hands and fingers.
- Fatigue and muscle weakness.
- Heat intolerance and feeling constantly hot.
- Trouble sleeping (insomnia) or sleep disturbances.
- Changes in menstrual patterns in women.
2. Graves' Ophthalmopathy (eye problems): Around 30% of people with Graves' disease may develop characteristic eye changes, which can include:
- Bulging or protruding eyes (exophthalmos).
- Dry eyes and a sensation of grittiness.
- Redness and eye pain.
- Double or blurred vision.
- Sensitivity to light.
- Difficulty moving the eyes.
3. Goiter: In some cases, the thyroid gland may enlarge and cause a visible or palpable goiter in the neck.
4. Skin changes: Some individuals may experience changes in the skin, such as warm, moist, or reddened skin, itching, or rashes.
5. Hair loss: Hyperthyroidism can lead to thinning hair and hair loss in some individuals.
6. Nail changes: Nails may become brittle and develop ridges or grooves.
Diagnosis of Graves' Disease
The diagnosis of Graves' disease is based on a combination of clinical symptoms and laboratory test results. Some methods used to diagnose Graves' disease include:
- Clinical evaluation and medical history: The doctor will conduct a detailed evaluation of the patient's symptoms and medical history. This will include questions about symptoms related to hyperthyroidism, eye changes, family history of thyroid diseases, risk factors, and any other relevant information.
- Thyroid function tests: Laboratory tests will be performed to measure thyroid hormone levels in the blood. Typical results in Graves' disease will show suppressed thyroid-stimulating hormone (TSH) levels and increased levels of thyroid hormones, such as triiodothyronine (T3) and thyroxine (T4).
- Antibody tests: Specific antibodies, such as thyroid-stimulating antibodies (TRAb), will be sought in the blood. TRAbs are present in most people with Graves' disease, and their presence confirms the diagnosis. Other antibodies, such as anti-thyroglobulin antibodies (anti-TG) and anti-thyroid peroxidase antibodies (anti-TPO), may also be evaluated.
- Physical examination and eye evaluation: The doctor will perform a physical examination to assess the size of the thyroid gland and look for physical signs of the disease, such as a visible goiter. Additionally, an eye evaluation may be conducted to detect signs of Graves' ophthalmopathy, such as eye protrusion (exophthalmos), redness, or dryness.
- Imaging tests: In some cases, imaging tests may be performed to evaluate the structure and function of the thyroid gland. Thyroid ultrasound can help determine the size of the gland and detect thyroid nodules. Radioactive iodine thyroid scan can assess iodine uptake and distribution in the thyroid gland.
Treatment of Graves' Disease
The treatment of Graves' disease focuses on controlling the overproduction of thyroid hormones, relieving symptoms, and preventing long-term complications. The following are the available treatment options:
Antithyroid medications: Antithyroid medications, such as methimazole and propylthiouracil, are used to reduce the production of thyroid hormones. These medications inhibit the function of the thyroid gland and can alleviate symptoms of hyperthyroidism. Treatment with antithyroid medications is generally administered for a specified period, which can vary from a few months to several years.
Radioactive iodine therapy: Radioactive iodine therapy, also known as thyroid ablation, is another treatment option. It involves the administration of an oral dose of radioactive iodine, which accumulates in the thyroid gland and destroys hyperactive thyroid cells. This therapy aims to reduce the function of the thyroid gland and normalize thyroid hormone levels. It is a commonly used option in cases where antithyroid medications fail to adequately control symptoms or when there is significant goiter.
Surgery: In less common or severe cases, surgery may be necessary to remove part or all of the thyroid gland. Thyroidectomy is performed under general anesthesia and may be an option when other treatments are not suitable or when there is concern about the presence of thyroid nodules or concurrent thyroid cancer.
It is important to note that the treatment of Graves' disease should be individualized and guided by a multidisciplinary medical team. This involves the involvement of endocrinologists, ophthalmologists, and other specialists as needed. Ophthalmologists can provide specific treatment and management for eye problems associated with Graves' disease. Endocrinologists are responsible for adjusting and monitoring the dosage of antithyroid medications and assessing the response to treatment. Other specialists, such as surgeons and nuclear radiologists, may play a role in surgical treatment or radioactive iodine therapy.
Regular medical follow-up is essential in managing Graves' disease. This involves periodic visits to the doctor to evaluate thyroid hormone levels, adjust medication dosage, monitor thyroid function, and track symptoms and possible complications. Adhering to prescribed treatment and following medical recommendations is crucial for controlling the disease and avoiding relapses or complications.
REFERENCES:
www.redaccionmedica.com/recursos-salud/diccionario-enfermedades/enfermedad-graves