Thursday, April 8, 2010

Graves Disease

Graves disease is a form of thyroiditis, an autoimmune disorder that stimulates the thyroid gland, being the most common cause of hyperthyroidism (overactivity of the thyroid). Also known in the English-speaking world simply as Graves' disease, it occurs most frequently in women (8:1 compared to men) of middle age. Symptoms include fatigue, weight loss and rapid heart beat. Because similar antibodies to those stimulating the thyroid also affect the eye, eye symptoms are also commonly reported. Treatment is with medication that reduces the production of thyroid hormone (thyroxin), or with radioactive iodine if refractory.

signs and symptoms of graves disease

Graves-Basedow disease is a disorder characterized by a triad of hyperthyroidism, goitre, and exophthalmos (bulging eyeballs).

Due to the many physiological actions of thyroid hormone, many symptoms and signs are linked to Graves' disease:

  • Cardiac: cardiac arrhythmias (especially atrial fibrillation), tachycardia (increased heart rate), collapsing pulse and widened pulse pressure (difference between systolic and diastolic BP) and congestive cardiac failure with peripheral edema, ascites, anasarca.
  • Endocrine: weight loss in the presence of increased appetite, intolerance to heat, elevated basal metabolic rate
  • Dermatological: profuse sweating, thyroid acropachy (clubbing) of the fingernails, onycholysis (fingernail destruction), palmar erythema, pretibial myxedema (3 to 5% of Graves' patients, not to be confused with the myxedema of hypothyroidism)
  • Neurological: tremor (especially noticable on extending the arms), apprehension, weakness, headache, proximal myopathy (difficulting rising from a chair or squatting position) and hyperactive deep tendon reflexes
  • Gastrointestinal: diarrhoea (common), vomiting (rare)
  • Ophthalmological: thyroid eye disease (TED) characteristic of Graves disease include lid retraction (Dalrymple sign) above the superior corneoscleral limbus, lid lag (von Graefe's sign), proptosis or forward displacement of the globes, periorbital swelling and chemosis.

Extremely manifested disease that can sometimes be life-threatening is called the thyroid storm.

diagnosis of graves disease

On the basis of the signs and symptoms, thyroid hormone (T4) and thyroid-stimulating hormone (TSH) are determined in the medical laboratory. T4 is markedly elevated, while TSH is suppressed due to negative feedback. An elevated protein-bound iodine level may be detected. A large goiter is sometimes seen on X-rays.

Thyroid-stimulating antibodies may be detected serologically.

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