The Diagnosis and Management of Hypothyroidism

Bhuvana Guha, MD, Guha Krishnaswamy, MD, And Alan Peiris, MD, PhD, MRCP

Disclosures

South Med J. 2002;95(5):475-480. 

In This Article

Clinical Manifestations

The manifestations of hypothyroidism result from a reduction in metabolic activity and a deposition of glycosaminoglycans. Clinical findings that may be seen in hypothyroidism are listed in Table 2 . It is important to note that symptoms may be nonspecific in the early stages of hypothyroidism and do not necessarily occur in sequence. These symptoms may include myalgia, arthralgia, muscle cramps, dry skin, headaches, and menorrhagia. Brittle nails, thinning of hair, pallor, and symptoms of carpal tunnel syndrome may also be seen. The characteristic delayed-relaxation phase of deep tendon reflexes may be noted, along with relative macroglossia. As hypothyroidism becomes more marked, hoarseness, peripheral edema, constipation, dyspnea, and weight gain may be seen. Other manifestations include pericardial effusion, ascites, decreased hearing, diastolic hypertension, galactorrhea, and hypothermia, along with neuropathy, ataxia, and sleep apnea. Psychiatric presentations may include depression, cognitive impairment, dementia, personality change, and, rarely, frank psychosis.[2] Hypothyroidism should also be considered in the presence of difficulty in weaning patients off of mechanical ventilators. The presence of goiter suggests primary rather than secondary hypothyroidism.

Several rare or unusual manifestations may prompt the patient to seek medical assistance. Bilateral carpal tunnel syndrome may complicate hypothyroidism.[3] Urticaria has been described in patients with autoimmune thyroid disease.[4] Primary pulmonary hypertension is often complicated by coexisting hypothyroidism.[5] Anemia, coagulopathy with easy bruising, myopathy, and a plethora of rheumatologic symptoms may plague the patient.[6] Anemia in patients with hypothyroidism may represent iron deficiency due to menorrhagia, and in some instances may be due to concomitant vitamin B12 deficiency.[6] Macrocytosis is a well-described feature of untreated hypothyroidism.

Myopathy may be a dominant presenting feature in some patients with hypothyroidism. In one study, patients with hypothyroidism underwent electroneuromyography (ENMG) to determine the presence of neuromyopathy.[7] A very high prevalence of abnormal ENMG results (87.5%) was seen in this population, with 46.6% having abnormalities consistent with myopathy, and another 43% with carpal tunnel syndrome.[7] Symptoms such as arthralgia, stiffness, paresthesia, joint swelling, and pseudogout may occur in patients with frank hypothyroidism.[6] Hyperuricemia and serous effusions involving the pleura, pericardium, peritoneum, and synovium have been described. Other autoimmune disorders may coexist or occur with increased frequency in patients with Hashimoto's thyroiditis. These disorders include pernicious anemia, vitiligo, rheumatoid arthritis, Sjogren's syndrome, systemic lupus erythematosus, chronic active hepatitis, polymyositis-like syndromes, and systemic sclerosis.[6,8]

Dyslipidemia and hyperhomocystinemia have been described in hypothyroidism and may contribute to accelerated atherosclerosis and early manifestations of coronary artery disease. Typically, elevated total cholesterol and low-density lipoprotein (LDL) levels and low levels of high-density lipoproteins have been described.[1]

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