Thyrotoxicosis: Treatment, symptoms, advice and help
Thyrotoxicosis is the clinical condition of a hypermetabolic state caused by increased thyroid hormones in the blood.
Thyrotoxicosis: Incidence, age and sex
The annual incidence of the disease is 0.5 cases per 1000 persons during a 20-year period, with the peak occurrence in people aged 20-40 years. All thyroid diseases occur more frequently in women than in men.
Signs and symptoms of thyrotoxicosis: Diagnosis
The symptoms are – tiredness, emotional liability, heat intolerance, weight loss, excessive appetite, palpitation. The signs of are – tachycardia, hot, moist palms, exophthalmos, lid lag / retraction, agitation, thyroid goitre and bruit .Thyroid dermopathy (pretibial myxoedema) is a rare condition characterized by thickening of the skin, thyrotoxicosis should always be considered in: children with a growth spurt, behaviour problems or myopathy; tachycardia or arrhythmia in the elderly, unexplained diarrhea, loss of weight. Thyrotoxicosis is diagnosed by estimating the free T3, T4 and TSH levels. A thyroid scan is required to diagnose an autonomous toxic nodule and differentiate it from a dominant swelling in a toxic multinodular goitre. TSH secretion is suppressed by the high level of circulating thyroid hormones and the normal thyroid tissue surrounding the nodule it itself suppressed and inactive.
Causes and prevention of thyrotoxicosis
The major causes in humans are Graves' disease, an autoimmune disease ( the most common etiology), toxic thyroid adenoma, toxic multinodular goitre, inflammation of the thyroid (thyroiditis), oral consumption of excess thyroid hormone tablets and an anti-arrhythmic drug structurally similar to thyroxine.
Cardiac arrhythmias are more common in older patients with thyrotoxicosis because of the prevalence of coincidental heart disease. Myopathy – Weakness of the proximal limb muscles is commonly found. Severe muscular weakness (thyrotoxic myopathy), resembling myasthenia gravis, occasionally occurs. Some degree of exophthalmos is common. In severe cases papilloedema and corneal ulceration occur.
Non-specific measures are rest and sedation. Specific measures include the use of anti-thyroid drugs, surgery and radio iodine.
Anti-thyroid drugs – those in common use are carbimazole and propylthiouracil. ?-Adrenergic blockers such as propranolol and nodolol are used to block the cardiovascular effects of the elevated T4. Iodides, which may reduce the vascularity of the thyroid, should be used only as immediate preoperative preparation in the 10 days before surgery.
Surgery – In diffuse toxic goitre and toxic nodular goitre with overactive internodular tissue, surgery cures by reducing the mass of overactive tissue.
Radioiodine destroys thyroid cells and, as in thyroidectomy, reduces the mass of functioning thyroid tissue to below a critical level.