Things To Know About Hypofunction Of The Thyroid Gland (Hypothyroidism)

In hypothyroidism, as the name indicates, there is anormal limits.
decline in the functioning of the thyroid gland. The glandWhat is TSH?
is either damaged as a result of an autoimmuneIt is a hormone secreted by the pituitary gland, lying in
disease of the thyroid gland, or in the case of anthe brain, which controls the activity of the thyroid
overactive thyroid gland, when more than the requiredgland. This hormone has got a highly stimulating action
amount of antithyroid drug has been administered.on thyroid activity, so that as soon as the activity of
Similarly, hypothyroidism may occur followingthe thyroid gland decreases (hypothyroidism), and the
radio-iodine treatment or surgery, in cases of anquantity of the thyroid hormone, the major being T4, or
overactive thyroid gland.even when it touches the lower limit of its normal
Subclinical hypothyroidism.range, there will be an increase in the secretion of TSH
The most characteristic feature of an underactivefrom the pituitary gland.
thyroid gland is that it remains asymptomatic for a longHence there is a close relationship between the
period, and there are only vague symptoms in thepituitary and thyroid glands so that a normal level of
beginning. Sometimes the diagnosis is made when athyroid hormones may be maintained in the blood as
person is undergoing routine tests for a generalfar as possible. (However, it may be said in passing,
medical check-up.that if hypothyroidism occurs as a result of the
The hidden nature of the disease is clear enough. Suchinvolvement/ disease of the pituitary gland, the levels
early cases of hypothyroidism are suspected,of TSH will not be elevated, although T4 may be on
diagnosed/investigated and labelled under the headthe lower side).
'Subclinical Hypothyroidism'. They may, however, still beSince the raised levels of TSH the blood is the most
in the infancy stage and have only minimal symptoms.sensitive/ earliest index for the decreased function of
This truly highlights the need for early diagnosis andthe thyroid gland, this test, along with T4 must be
treatment of all cases of hypothyroidism.carried out whenever there is the slightest suspicion
When to suspect subclinical hypothyroidism?regarding the underactivity of the thyroid gland.
The disease may be suspected when the patientDoes subclinical hypothyroidism require treatment?
feels lethargic, especially in the case of a patientDifficulty does arise in such cases. However, it may be
suffering from hyperthyroidism who is undergoingsaid that in the absence of significant, rather
antithyroid drug treatment, or radio-iodine therapy, ortroublesome symptoms, the physician will have to
has undergone surgery of the thyroid gland. Or, themake his own judgement for the initiation of therapy. If
condition may occur in cases which have a positiveno therapy is considered necessary for the time being,
family history of hypothyroidism.the patient must be monitored at least 3-6 monthly, so
How to diagnose subclinical hypothyroidism?that the disease does not progress unnoticed.
Once suspected, estimation of the thyroid-stimulatingAs regards the size of the thyroid gland, in cases of
hormone (TSH) in the blood should be carried out. Thehypothyroidism, it may be noted that the gland may be
levels of this test will be elevated significantly, althougheither enlarged or atrophied, or may remain normal in
the levels of T4 may be just on the lower side of thesize. Hence the size of the thyroid does not indicate
normal, or just below the normal level. T3 does notthe activity of the gland, and, therefore, one has to
playa significant! diagnostic role in the detection ofdepend on the levels of thyroid function tests in the
hypothyroidism, and its level may be found withinblood.