Disease Symptoms

The symptoms of thyroid disease are grouped in two syndroms: hypothyroidism and hyperthyroidism, depending on the serum concentration on thyroid hormones.

Hypothyroidism is a complex syndrome determined by the reduced serum levels of thyroid hormones, and it may have many causes such as iodine deficiency (the most common cause), autoimune disorders (such as Hashimoto thyroiditis), sarcoidosis, scleroderma Riedel’s thyroiditis, or some medical procedures such as thyroidectomy or irradiation for cancer.

The symptoms of hypothyroidism are various and depend on the concentration of thyroid hormones and the patient’s age. Therefore, in infants and children the neurological signs and symptoms are: learning disabilities, inactivity, cretinism (the type of mental retardation caused by this disorder) with severe consequences. Other signs and symptoms include short stature, opened fontanelles even after the age of 2 years, hypotonia, edema and delayed bone age.

In adults , hypothyroidism it usually has an insidious onset and many patients come to the doctor mainly because of the goiter and the edema. The skin is dry, cold,the epiderm is thin, the nails growth is reduced and the hair is brittle and dry and hairloss occurs in many cases. Weight gain is very common, although the patient has a poor apetite, and is caused by fluid retention in the subcutaneous tissue. The cardiovascular symptoms are bradycardia, hypertension, cardiomyopathy and pericardial effusion. The libido is reduced and the fertility decreases and women present menstrual irregularities.

Myxedema coma is a severe complication of hypothyroidism and consists in hypoglicemia, hyponatremia, hypothermia, extreme weakness, and cerebellar ataxia, and it has a high mortality rate.The elevated concentration of circulating thyroid hormones determines the syndrome known as hyperthyroidism or thyrotoxicosis, caused in most cases by Grave’s disease, which occurs in 2% of women and 0.15% of men.

The signs and symptoms of thyrotoxicosis are: unexplained weight loss, increased sweating, polidipsia, increased apetite, diarheea, due to increased metabolic rate.  The neurological signs and symptoms are:hyperreflexia, proximal myopathy without fasciculation and a specific form of hypokalemic periodic paralysis. The most common cardiac manifestations are tachycardia and atrial fibrilation.

The result of the sympathetic overactivity, the lid retraction causes a specific staring appearance, proptosis, periorbital edema, ophthalmoplegia. Patients with thyroid eye disease may report episodic blurring of vision or diplopia, periorbital edema, scleral injection, watering of the eyes, or irritation with a foreign body sensation.

The most severe (and in many cases life threatening) complication of hyperthyroidism is th “thyroid storm” or the thyrotoxic crisis. The patient presents all the symptoms of the exacerbated hyperthyroidism and, in addition, jaundice, fever, delirium, seizures, coma, cardiac failure and arrhythmia. The mortality rate is 30% even with treatment.Clinical features of hyperthyroidism can mimic symptoms of other disorders such as panic attacks,weight loss associated with malignancy, mania and pheochromocytoma, but the differential diagnosis can be made after th laboratory evaluation of the T3 and T4 levels. These tests have diagnostic value in hypothyroidism as well.