There are several causes of hyperthyroidism, including Graves' disease. Hyperthyroidism is a thyroid imbalance in which thyroid gland produces the thyroid hormone ‘thyroxine’ in excess. Thyroiditis (inflammation of the thyroid) is another leading cause of hyperthyroidism. Medical conditions, such as toxic adenoma and Plummer's disease may also be a potential cause of hyperthyroidism. [Read: What is Hyperthyroidism]
Common Causes of Hyperthyroidism
- Graves' Disease – In this condition, the thyroid (goitres) enlarges due to excessive secretion of the thyroid gland hormone; this being one of the most common causes of hyperthyroidism. The autoimmune disease occurs as the immune system turns against the thyroid gland and impacts its function. Antibodies produced by the immune system get attached to certain activating sites on the thyroid gland making thyroid produce more hormones. [Read: Symptoms of Graves' Disease]
- Hyper functioning Thyroid Nodules – Toxic adenoma, toxic multinodular goitre and Plummer's disease are thyroid nodules that can lead to hyperthyroidism. In these medical conditions, one or more adenomas of the thyroid gland produce T-4 in excess, which may be evident through the enlarged liver.
- Thyroiditis – Inflammation of the thyroid gland is another cause of hyperactive thyroid. Owing to inflammation, excess thyroid hormone stored in the gland leaks into the bloodstream. Subacute thyroiditis, a kind of thyroiditis that causes pain in the thyroid gland, may also be the reason for hyperthyroidism. Postpartum thyroiditis, thyroiditis occurring after pregnancy may also be the reason for hyperthyroidism.
Less Common Causes of Hyperthyroidism
- Toxic Nodular Goitre – It is a single nodule in the thyroid representing benign (non-cancerous) lumps or tumours in the gland, which may also cause the thyroid gland to produce thyroxin excessively.
- Thyroid Hormone Dosage – Patients on an excessive dosage of iodine or thyroid hormone dosage and especially those on medications containing T3 are at a risk of developing hyperthyroidism. Therefore, it is important for patients on thyroid doses to talk to the doctor and prevent hyperthyroidism.
Risk Factors for Hyperthyroidism
Women are more likely than men to develop hyperthyroidism. Among other factors that increase the likelihood of developing hyperthyroidism are:
- thyroid infections or problems in the past (such as goitre),
- family history of thyroid disease,
- history of thyroid surgery,
- type 1 diabetes,
- pernicious anaemia and
- primary adrenal insufficiency.
The following individuals are more likely to have hyperthyroidism.
- Expecting mothers.
- Women, who have delivered baby within the past six months.
- Those who eat large amounts of food containing iodine.
- Those on iodine-containing medications (such as amiodarone).
- Those on heart medications.
[Read: When to Seek Medical Advice for Hyperthyroidism]
Excessive increase in thyroid hormone production can lead to mild to severe medical conditions that affect the overall well-being of an individual. The medial condition can become serious if ignored, but can be easily treated in its initial phase.
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