This is the over whelming secretions of thyroid hormone above the body's need.Unlike in hypothyroidsm in this condition the main cause of defect is on the gland only and not originated from the pituitary or hypothalamus.
Graves's Disease
This is having a synonym as Diffuse Toxic Goiter .This is most probably attacking young children but rarely target adult.
In this condition the gland is stimulated on TSH receptors not by TSH from the pituitary but by the autoimmune antibodies in the blood.Hence when pituitary is normal,and hypothalamus is normal but the gland is overstimulated by the body's own defence system.
These antibodies are having prolonged gland stimulating effects and since they are only mimiking the action of pituitary and testing for TSH in the blood may not give positive results.
The required results will be yielded only by the titration of these antibodies in the blood.
Symptoms
1.Diffusely enlarged nontender goiter
2.Nervousness,weakness,and insomnia.
3.Heat intolerance and heavy sweating.
4.Weight loss inspite of elevated appetite
5.Tremour,muscle weakness
6.Palpitation and tachky arrythmias
7.Incomplete and slow eye lid closing (Exophthalmos)
8.Loose motion
9.Periorbital edema.
Plummer's Disease
This a highly toxic form of nodular goiter.This is more common in adults over 50 years and mostly females.The actual cause is unknown but preferably arise from untreated long standing non toxic goiter.
In this disease one or more adenomatous nodules of the thyroid gland autonomously secreting excess hormone without being stimulated by pituitary hormone.Enlargedv nodules are formed within the goiter.
Basically deficiency in dietary iodine may cause not only hypothyroidsm but some times cause hyperthyroidsm too as follows by counter activity.
a)Availability of less dietary iodine leads to less T-4 production.
b)Less T-4 production may induce more mutations and introductions of TSH cells.
c)TSH cells on pseudostimulation by body's auto immune antibodies will induce more nodular autonomous T-4 producing cells which secretes automatically without getting any pituitary stimulation excess T-4 hormone result in Hyperthyroidsm.
Symptoms
Many of the symptoms are similar to Graves disease except the goiter shows enlarged nodules inside and usually in this disease slow eye lid movement is absent.
Heart abnormalities are more impressive and predominant in this disease.
Jodebasedow Phenomenon
It is a kind of Hyperthyroidsm in which there is a over production of thyroid hormone due to sudden large intake of iodine.either by food,by drugs (e.g.Antiarrhythmic drugs like amiodarone) or by contrast media like radio iodine.
Factitious Hyperthyroidsm
This hyperthyroidsm occurs mostly by misguided weightloss treatments which involves excessive intake of thyroid replacement agents.
Many of the symptoms of hyperthyroidsm like exophtalmia,glandular swelling.and auto immune activity are all absent in the diagnosis of this disease.
TREATMENTS
1.Beta-adrenergic blockers-Propranolol
Propranolol can reduce some of the peripheral symptoms of hyperthyroidsm such as
Palpitations
Tremour
Tachycardia(Increased heart beats)
Sweatting
Nervousness
In addition to the above symptomatic releives propranolol also inhibit the conversion of T-4 to T-3 in the circulation.
2.Propylthiouracil and Methimazole
Chemically these are sulphur containing thiamides.
They suppress the production of T-3 and T-4 by inhibiting the coupling of thyroglobulin molecule.
Can be taken orally
Side effects 1.Agranulocytosis (Rare but very serious)
2.Rash(Most common)
3.Edema
3.Iodine salts
The mechanism is not clear.Usually thyroid gland cannot take iodide as it is unless it should be converted into nonpolar inorganic iodine molecule.Hence ingesting large quantity of polar iodide ion may well result in decreased conversion into polar form and decreased iodine uptake and eventually leads to decreased productions of the T-4,decreased vascularity and decreased gland size.
Iodides are nowadays not used as a sole thrapy but in conjunction with thioamide and propranolol in thyroid cresis.Iodides also can be used prior to surgery.
Preparations 1.A mixture of iodine and potassium iodide (Lugol's solution)
2.Potassium iodide.
Side effects
1.Anaphylactic reactions such as Angioedema and swelling of the larynx
2.Iodism charectorised by burning taste,and mouth
3.soreness of teeth and mouth
4.swelling of eyelids
5.Cold like senses
6.Breathing problem
7.Enlargement of the salivary glands
4.Ionic inhibitors
These are perchlorates and thiocyanates.
They competitively inhibit the iodide transport mechanism.
Nowadays their use is limited in favour of other advanced therapies
5.Radio Iodine
The mechanism is thyroid gland can readily absorb iodine in radioform which can ablate the gland and decrease the hormone production.
It can be used very coveniently to adults ove 21 years.
This is very useful in treating Profuse Grave's Disease which is not responding properly to drugs and surgery.
One common advantage with iodine is that there is no any upto date proof Iodine can cause cancer
Side effects
Delayed hypothyroidsm has been observed.
Contraindications
Radio iodine is highly contraindicated in pregnancy and milk feeding.
THYROID STROM
It is a dangerous emergency situation caused by extreme effects of hyperthyroidsm.
This condition is elevated by sickness,trauma,stress and surgery of the patient who is already thyrotoxic.
Treatments include the treatments of hyperthyroidsm especially and preferably with the beta blockers like propranolol,and glucocorticoids to inhibit the plasma conversions of T-3 to T-4.
Other options are a)Propyl thiouracil and methimazole,
b)I.V sodium iodide injections
