Hyperthyroidism and Thyrotoxicosis

00:01 The symptoms of hyperthyroidism are numerous.

00:05 They include heat intolerance, palpitations, dyspnea or shortness of breath, tremulousness, menstrual irregularities and increase in the frequency of stool and diarrhea, weight loss and increased appetite.

00:21 In the rest of the body there may be proximal muscle weakness, patients may manifest fatigue and difficulty sleeping.

00:28 They may also have mood disturbances and be very irritable.

00:31 In all the patients, the classic symptoms tend to be absent.

00:35 However, cardiac manifestations are much more prominent.

00:38 Patients may present with abnormal heart rates or atrial fibrillation and may eventually develop heart failure.

00:47 The patterns of abnormal thyroid function tests are as follows: The initial evaluation is always based on the clinical signs and symptoms.

00:56 Check her TSH alone initially to gauge whether the patient is hyper or hypothyroid.

01:02 In the setting of suppressed TSH, then go on and check her T4 and T3 level.

01:08 The typical pattern of hyperthyroidism seen in this case is a low TSH and an elevated T4 and/or elevated T3.

01:18 This is the hallmark of primary hyperthyroidsm.

01:22 A word on terminology.

01:24 Thyroid hormone excess from different sources.

01:28 First of all, endogenous thyroid disorders will cause thyrotoxicosis which is the clinical syndrome of thyroid hormone excess manifesting with the symptoms described above.

01:40 Pituitary tumors can also cause an increase secretion of thyroid stimulating hormone, which again, will lead to a hyperthyroid state.

01:49 This, however, is very very rare.

01:52 You can also have thyrotoxicosis from taking exogenous levothyroxine.

01:57 So patients with a low thyroid who are over medicating themselves with thyroxine may manifest symptoms of thyrotoxicosis.

02:06 Hyperthyroidism is the more specific term to describe thyroid gland overactivity.

02:13 The most common causes though, are Graves' disease and toxic adenomas.