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Hyperthyroidism (Thyrotoxicosis, grave diseases)

It is a situation in which your thyroid gland produces too much of the hormone thyroxine. It causes sudden weight loss, a rapid or irregular heartbeat, sweating, and nervousness or irritability.

Causes of Hyperthyroidism (thyrotoxicosis)

  1. Thyroid overactivity,
  2. Extrathyroid.

(1) Thyroid overactivity:

(a) Grave’s diseases: Formation of goiter in Grave’s disease:

It is an autoimmune disease in this disease circulating antibody TSH receptor stimulating antibody (TSH – R Ab) or thyroid stimulating immune globulin (TSI), TSI receptor antibody (TSR- R [block] Ab) are formed against the TSH receptor and activate the receptor. It makes the gland hyperactive. In Graves’ disease, treatment with antithyroid medications must be given for six months to two years, in order to be effective. Even then, upon cessation of the drugs, the hyperthyroid state may recur.

Exophthalmos: Most people with hyperthyroidism develop some degree of protrusion of eyeballs.

The causes are –

  • Edematous swelling of retro-orbital tissue,
  • Degenerative changes in the extraocular muscles.
  • Exophthalmos itself is an autoimmune process.

(b) Solitary toxic adenoma,

(c) Toxic multinodular goiter,

(d) Thyroiditis,

(e) TSH – secreting pituitary tumor

(2) Extrathyroidal:

(a) Administration of T3 or T4 (Factitious or iatrogenic hyperthyroidism)

(b) Ectopic thyroid tissue.

Symptoms of hyperthyroidism It can mimic other health problems, which may make it complicated for your doctor to diagnose. When the thyroid gland is overactive the body’s processes speed up and you may experience nervousness, anxiety, rapid heartbeat, hand tremor, excessive sweating, weight loss, and sleep problems, among other symptoms.

  • Intolerance to heat,
  • Increased sweating, a warm soft skin,
  • Weight loss,
  • Hyperphagia,
  • A high state of excitability,
  • Varying degree of diarrhea.
  • Extreme fatigue but the inability to sleep.


  • Fine outstretched,
  • ↑ Pulse pressure.

Diagnostic test for hyperthyroidism:

(a) Measurement of plasma cone. of free T4. (or T3) by RIA.

(b) BMR is usually increased 10 to as high as 100.

(c) Measurement of plasma conc. of TSH by RIA.

(d) Measurement of plasma conc. of TSI by RIA; usually high in thyrotoxicosis but low in thyroid adenoma.

Treatment in hyperthyroidism: Surgical removal of most of the thyroid gland. Antithyroid medications, such as methimazole, stop the thyroid from making hormones. They are a common treatment.