Hyperthyroidism (or "overactive thyroid gland") is the clinical syndrome caused by an excess of circulating free thyroxine (T4) or free triiodothyronine (T3), or both.

Causes

Hyperthyroidism is the result of excessive thyroid hormone production, causing an overactive height growth and increased speed of all the body's organs and intestines

Thyroid hormone generally controls the pace of all of the processes in the digestive system. This pace is called one's metabolism. If there is too much thyroid hormone, every function of the body tends to speed up. The thyroid gland regulates the body temperature by secreting two hormones that control how quickly the body burns calories and energy. If the thyroid produces too much hormone, the condition is called hyperthyroidism, but if too little is produced, the result is hypothyroidism.

Major causes in humans are:

* Graves' disease (the most common etiology with 70-80%)

* Toxic thyroid adenoma

* Toxic multinodular goitre

Other causes of hyperthyroxinemia (high blood levels of thyroid hormones) are not to be confused with true hyperthyroidism and include subacute and other forms of thyroiditis (inflammation) and struma ovarii (a teratoma). Thyrotoxicosis (symptoms caused by hyperthyroxinemia) can occur in both hyperthyroidism and thyroiditis. When it causes acutely increased metabolism, it is sometimes called "thyroid storm", a life-threatening event characterized by tachycardia, hypertension, and fever.

Excess thyroid hormone from pills can also cause hyperthyroidism. Amiodarone, a heart medication, can sometimes cause hyperthyroidism. Hamburger toxicosis is a condition that occurs sporadically and is associated with ground beef contaminated with thyroid tissue, and thus thyroid hormone.

Postpartum thyroiditis occurs in about 7% of women during the year after they give birth. PPT typically has several phases, the first of which is hyperthyroidism. Many times, the hyperthyroidism corrects itself within weeks or months without any treatment necessary.

Signs and symptoms

Major clinical weight loss (often accompanied by a ravenous appetite), anxiety, intolerance to heat, fatigue, weakness, hyperactivity, irritability, apathy, depression, polyuria, polydipsia, and sweating. Additionally, patients may present with a variety of symptoms such as palpitations and arrhythmias (notably atrial fibrillation), shortness of breath (dyspnea), loss of libido, nausea, vomiting, osteoporosis and diarrhea. In the elderly, these classical symptoms may not be present and they may present only with fatigue and weight loss leading to apathetic hyperthyroidism. Thyrotoxic crisis comes when the sick person is having stress. Its symptoms are increase of body temperature to over 40 degrees Celsius, tachycardia, arrhythmia, vomiting, diarrhea, dehydration, icterus, coma and death.

Neurological manifestations are tremor, chorea, myopathy, and periodic paralysis. Stroke of cardioembolic origin due to coexisting atrial fibrillation may be mentioned as one of the most serious complications of hyperthyroidism.

As to other autoimmune disorders related with thyrotoxicosis, an association between thyroid disease and myasthenia gravis has been well recognized. The thyroid disease, in this condition, is often an autoimmune one and approximately 5% of patients with myasthenia gravis also have hyperthyroidism. Myasthenia gravis rarely improves after thyroid treatment and the relationship between the two entities is as yet unknown. Some very rare neurological manifestations that are reported to be dubiously associated with thyrotoxicosis are pseudotumor cerebri, amyotrophic lateral sclerosis and a Guillain-Barré-like syndrome.

Minor ocular signs, which may be present in any type of hyperthyroidism, are eyelid retraction ("stare") and lid-lag. These "fear-like" eye-signs result from thyroid hormone's exacerbation of the action of norepinephrine. In hyperthyroid stare (Dalrymple sign) the eyelids are retracted upward more than normal (the normal position is at the superior corneoscleral limbus, where the "white" of the eye begins at the upper border of the iris). In lid-lag (von Graefe's sign), when the patient tracks an object downward with their eyes, the eyelid fails to follow the downward moving iris, and the same type of upper globe exposure which is seen with lid retraction occurs, temporarily. These signs disappear with treatment of the hyperthyroidism, or treatment by certain anti-adrenergic drugs.

Neither of these ocular signs should be confused with exophthalmos (protrusion of the eyeball) which occurs in one thyroid-related disease (Graves' disease), but which is not caused by the hyperthyroid state in that disease, and is unrelated to it. This forward movement of the eyes is due to the inflammation in the retro-orbital fat. Exophthalmos, when present, may exacerbate hyperthyroid lid-lag and stare, however.

Diagnosis

A diagnosis is made through blood tests, by measuring the level of thyroid-stimulating hormone (TSH) in the blood. A low TSH (the job of TSH taken over by thyroid-stimulating immunoglobulin [TSI] that act like TSH) indicates increased levels of T4 and/or T3 in the blood. Measuring specific antibodies, such as anti-TSH-receptor antibodies in Graves' disease, may contribute to the diagnosis. In all patients with hyperthyroxinemia, scintigraphy is required in order to distinguish true hyperthyroidism from thyroiditis.

Treatment

The major and generally accepted modalities for treatment of hyperthyroidism in humans involve initial temporary use of suppressive thyrostatics medication, and possibly later use of permanent surgical or radioisotope therapy. All approaches may cause under active thyroid function (hypothyroidism) which is easily managed with levothyroxine supplementation.

Temporary medical therapy

Thyrostatics

Thyrostatics are drugs that inhibit the production of thyroid hormones, such as carbimazole (used in UK ) and methimazole (used in US), or where these not tolerated then propylthiouracil. Thyrostatics are believed to work by inhibiting the iodination of thyroglobulin by thyroperoxidase.

If too high a dose is used in pharmacological treatment, patients can develop symptoms of hypothyroidism.

Beta-blockers

Beta-blockers do not treat, but rather mask, common symptoms of hyperthyroidism such as palpitations, trembling, and anxiety. Propranolol in the UK , and Metoprolol in the US , are most frequently used to augment treatment for hyperthyroid patients.

Permanent treatments

Surgery as an option predates the use of the less invasive radioisotope therapy, but is still required in cases where the thyroid gland is enlarged and causing compression to the neck structures, or the underlying cause of the hyperthyroidism may be cancerous in origin.

Surgery

Surgery (to remove the whole thyroid or a part of it) is not extensively used because most common forms of hyperthyroidism are quite effectively treated by the radioactive iodine method. However, some Graves' disease patients who cannot tolerate medicines for one reason or another, patients who are allergic to iodine, or patients who refuse radioiodine opt for surgical intervention. Also, some surgeons believe that radioiodine treatment is unsafe in patients with unusually large gland, or those whose eyes have begun to bulge from their sockets, claiming that the massive dose of iodine needed will only exacerbate the patient's symptoms. The procedure is quite safe - some surgeons even perform partial thyroidectomies on an out-patient basis.

HOMOEOPATHIC TREATMENT

Amylenum nitrosum : Deep facial flushing. Pulsation all over body. Anxiety as if something might happen. Must have fresh air. Throbbing in head. Bursting out feeling in ears.

Kali iodatum : Fright at every trifle, every little noise. Starting, apprehensive. Excited, quarrelsome. Eyeballs painful on movement. Throat swelling of thyroid gland with sensitiveness to touch and pressure. Choking in trachea. Irregular action of heart and pulse, with tensive pain across chest, especially affecting right ventricle, which gradually becomes dilated. Tremor of limbs, tearing above right malleolus. Gait disturbed. Emaciation Marasmus. Nervous mobility. Trembling, Subsultus tendinum.

Lycopus : Increased mental and physical activity in evening. Vertigo, Pressure in forehead, Eyes feel full and heavy. Constriction across lower half of thorax. Quick, weak pulse, occasional haemoptysis.

Ferrum : Confusion and heaviness in the head; vertigo. Epistaxis. Constrictive sensation in the throat. Oppressed short breathing.

Hypericum : Apprehensive. Mental excitement. Great heaviness in the head; confusion, vertigo. Dryness of the lips and mouth. Great thirst, desire for warm drinks. Anxiety in chest in forenoon with short breath. Palpitation, pulse rapid and hard.

Baryta iodata : Glandular enlargement and new growth, on indications suggested by its two elements.

Bromine : Symptoms are those of Iodine with the exception that it is used in a blonde patient of thin muscular fibre and pink skin.

Duboisinum : Excitable. Dizziness. Pupils widely dilated. Ringing in ears. Throat dry. A rapid pulse; faintness.

Natrum mur .: Palpitation, hearts pulsations shaking the body. Short of breath on least exertion. Lachrymose, worse with sympathy. Emaciation of throat; craves salt.

Iodine : Confusion of head. Anxiety, fear, shuns people. Restless agitation. Feeling of depression above eyes. Protrusion of eyeballs. Salivation. Pyrosis. Inflation of abdomen.

Belladonna : Palpitation of the heart, increased by exercise. Pulsation of the larger arteries. Irritability of the heart. Thyroid enlargement. Eyeball appears to become increased in size. Eyelids do not close, even in sleep, excitability. Irritability. Depression.

NOTE :

Any information given in this article is not intended to be taken as a replacement for medical advice. Any person with a condition requiring medical attention should consult a qualified classical homœopath.

Reference (Source):

Wikipedia Encyclopedia (http://en.wikipedia.org/wiki/Thyroid)