The key difference between Graves Disease and hyperthyroidism is that the Graves’ disease is a pathological condition while the hyperthyroidism is a functional abnormality which is a result of an ongoing pathological process.
An increase in the level of free thyroxin hormones is known as the hyperthyroidism. Hyperthyroidism can be due to various causes, and Graves’ disease is one such pathological condition that abnormally increases the thyroxin levels in the body. Graves’ disease is defined as an autoimmune thyroid disorder with an unknown etiology. Ít is a pathological condition that gives rise to hyperthyroidism which is a functional abnormality due to the ongoing pathological process.
CONTENTS
1. Overview and Key Difference
2. What is Graves’ Disease
3. What is Hyperthyroidism
4. Similarities Between Graves’ Disease and Hyperthyroidism
5. Side by Side Comparison – Graves’ Disease vs Hyperthyroidism in Tabular Form
6. Summary
What is Graves’ Disease?
Graves’ disease is an autoimmune thyroid disorder with an unknown etiology.
Pathogenesis
An autoantibody of IgG type called “Thyroid Stimulating Immunoglobulin” binds to TSH receptors in the thyroid gland and mimics the action of TSH. Therefore, as a result of this increased stimulation, there is an excessive production of the thyroid hormone associated with the hyperplasia of the thyroid follicular cells. The result is the diffuse enlargement of the thyroid gland.
The increased stimulation by the thyroid hormones expands the volume of retro-orbital connective tissues. This with the edema of the extraocular muscles, accumulation of the extracellular matrix materials, and infiltration of the periocular spaces by lymphocytes and fat tissues weaken the extraocular muscles, thus pushing the eyeball forward.
Morphology
There is diffuse enlargement of the thyroid gland. Cut sections will show a red meaty appearance. Follicular cell hyperplasia that is characterized by the presence of a large number of small follicular cells is the hallmark microscopic feature.
Clinical Features
The distinguishing clinical features of Graves disease are,
- Diffuse goiter
- Exophthalmos
- Periorbital myoedema
In addition to these symptoms, the patient can have the following clinical features because of the increased thyroid hormone levels.
- Warm and flushed skin
- Increased sweating
- Loss of weight and increased appetite
- Diarrhea due to increased bowel motility
- Increased sympathetic tone leads to tremors, insomnia, anxiety and proximal muscle weakness.
- Cardiac manifestations: tachycardia, palpitations, and arrhythmias.
Investigations
- Thyroid function tests to confirm thyrotoxicosis
- Checking for the presence of thyroid stimulating immunoglobulin in blood.
Figure 01: Graves Disease
Management
- Medical treatment
The administration of antithyroid drugs such as carbimazole and methimazole is extremely effective. The most common adverse effect associated with the continuous use of these drugs is the agranulocytosis, and all the patients who are under antithyroid drugs should be advised to seek immediate medical attention in case of unexplained fever or a sore throat.
- Radiotherapy with radioactive iodine
- Surgical resection of the thyroid gland. This is the last resort option which is used only when the medical interventions fail to achieve the desired outcome.
What is Hyperthyroidism?
The state of increased levels of free thyroxin hormones is known as hyperthyroidism.
Causes
- Graves’ disease
- Toxic multinodular goiter
- Follicular adenoma
- Pituitary tumors
- Neonatal hyperthyroidism due to maternal Graves disease.
Figure 02: Hyperthyroidism
Clinical Features
- The increase in the sympathetic activity and osmolarity are the main causes
- Flushing of the skin
- Increased basal metabolic rate results in a reduction in the body weight with a characteristic increase in the appetite.
- Tremors
- Hyperactivity
- Insomnia
- anxiety
- Proximal muscle weakness and reduced muscle mass – thyroid myopathy
- Intestinal hypermotility causing diarrhea
- Tachycardia, palpitations, and The increased workload on the cardiac muscles can eventually impair the ventricular functions giving rise to cardiac failure.
- Osteoporosis due to increased bone resorption
Investigations
1. Thyroid function test
- To confirm thyrotoxicosis
- Free T4 levels
- Rarely if thyrotoxicosis is due to TSH secreting pituitary tumor TSH levels could be increased
2. Radioiodine uptake test
- Diffusely increased uptake in the whole gland in Grave’s disease
- Focally increased uptake in toxic adenomas
3. Testing for the thyroid stimulating immunoglobulins to diagnose Graves disease
What is the Similarity Between Graves’ Disease and Hyperthyroidism?
- Graves’ disease is one cause of hyperthyroidism. Therefore, there is an increase in the thyroxin level in the blood.
What is the Difference Between Grave’s Disease and Hyperthyroidism?
Graves’ disease is a pathological condition while hyperthyroidism is a functional abnormality which is a result of an ongoing pathological process. This is the main difference between Graves disease and hyperthyroidism. Furthermore, by definition, Graves disease is an autoimmune thyroid disorder with an unknown etiology. On the other hand, Hyperthyroidism is the state of the increased level of free thyroxin hormones is known as hyperthyroidism. The infographic below presents more differences between Graves disease and hyperthyroidism in a tabular form based on their causes, clinical features, and investigations.
Summary – Graves Disease vs Hyperthyroidism
Graves disease is a pathological condition which is defined as an autoimmune thyroid disorder with an unknown etiology. Hyperthyroidism is the state of the increased level of free thyroxin hormones which can be due to various causes including the Graves disease. This is the main difference between Graves disease and hyperthyroidism.
Reference:
1.Parveen Kumar. Kumar and Clark’s Clinical Medicine. Edited by Michael L Clark, 8th ed.
Image Courtesy:
1.’14593143777/’ by Internet Archive Book Images (CC0) via Flickr
2.’Blausen 0534 Goiter’By Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work, (CC BY 3.0) via Commons Wikimedia