INTRODUCTION:– Hyperthyroidism, also known as overactive thyroid and hyperthyreosis, is the condition that occurs due to excessive production of thyroid hormone by the thyroid gland. Thyrotoxicosis is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidism
Sign & symptoms:-
Hyperthyroidism may be asymptomatic or present with significant symptoms. Some of the symptoms of hyperthyroidism include
1) nervousness, irritability,
2) increased perspiration,
3) heart racing,
4) hand tremors
5) , anxiety, difficulty sleeping,
6) thinning of the skin,
7) fine brittle hair,
8) Muscular weakness—especially in the upper arms and thighs.
9) More frequent bowel movements may occur, and diarrhea is common.
10) Weight loss, sometimes significant, may occur despite a good appetite
The major causes in humans are:
• Graves’ disease. An autoimmune disease
• Toxic thyroid adenoma
• Toxic multinodular goiter
High blood levels of thyroid hormones (most accurately termed hyperthyroxinemia) can occur for a number of other reasons:
• Inflammation of the thyroid is called thyroiditis. There are several different kinds of thyroiditis including Hashimoto’s thyroiditis (Hypothyroidism immune-mediated), and subacute thyroiditis . These may be initially associated with secretion of excess thyroid hormone, but usually progress to gland dysfunction and, thus, to hormone deficiency and hypothyroidism.
• Oral consumption of excess thyroid hormone tablets is possible (surreptitious use of thyroid hormone),
• Amiodarone, an anti-arrhythmic drug, is structurally similar to thyroxin and may cause either under- or over activity of the thyroid.
• Postpartum thyroiditis (PPT) occurs in about 7% of women during the year after they give birth.
• A Struma ovarian is a rare form of monodermal teratoma that contains mostly thyroid tissue, which leads to hyperthyroidism.
• Excess iodine consumption notably from algae such as kelp
DIAGNOSIS:- Measuring the level of thyroid-stimulating hormone (TSH), produced by the pituitary gland (which in turn is also regulated by the hypothalamus’s TSH Releasing Hormone) in the blood is typically the initial test for suspected hyperthyroidism. A low TSH level typically indicates that the pituitary gland is being inhibited or “instructed” by the brain to cut back on stimulating the thyroid gland, having sensed increased levels of T4 and/or T3 in the blood. In rare circumstances, a low TSH indicates primary failure of the pituitary, or temporary inhibition of the pituitary due to another illness (euthyroid sick syndrome) and so checking the T4 and T3 is still clinically useful.
Anti thyroid drugs
Hydrostatics (ant thyroid drugs) are drugs that inhibit the production of thyroid hormones, such as carbimazole (used in UK) and methimazole (used in US), and propylthiouracil.
Many of the common symptoms of hyperthyroidism such as palpitations, trembling, and anxiety are mediated by increases in beta adrenergic receptors on cell surfaces.
People with autoimmune hyperthyroidism should not eat foods high in iodine, such as edible seaweed and kelps.