endocrine and metabolic disorders
Hypothyroidism
Symptoms and Signs of Hypothyroidism
Symptoms and signs of primary hypothyroidism are often subtle and insidious. The most common presenting symptoms are fluid retention and puffiness, especially periorbitally; tiredness; cold intolerance; mental fogginess. Various organ systems may be affected with many possible signs and symptoms, including: Metabolic manifestations: Cold intolerance, modest weight gain (due to fluid retention and decreased metabolism), hypothermia Neurologic manifestations: Forgetfulness, paresthesias of the hands and feet (often due to carpal tunnel syndrome caused by deposition of proteinaceous ground substance in the ligaments around the wrist and ankle); slowing of the relaxation phase of deep tendon reflexes Psychiatric manifestations: Personality changes, depression, dull facial expression, dementia or frank psychosis (myxedema madness) Dermatologic manifestations: Facial puffiness; myxedema; sparse, coarse and dry hair; coarse, dry, scaly and thick skin; carotenemia, particularly notable on the palms and soles (caused by deposition of carotene in the lipid-rich epidermal layers); macroglossia due to deposition of proteinaceous ground substance in the tongue Ocular manifestations: Periorbital swelling due to infiltration with the mucopolysaccharides hyaluronic acid and chondroitin sulfate, droopy eyelids because of decreased adrenergic drive Gastrointestinal manifestations: Constipation Gynecologic manifestations: Menorrhagia or secondary amenorrhea Cardiovascular manifestations: Slow heart rate (a decrease in both thyroid hormone and adrenergic stimulation causes bradycardia), enlarged heart on examination and imaging (partly because of dilation but chiefly because of pericardial effusion; pericardial effusions develop slowly and only rarely cause hemodynamic distress) Other manifestations: Pleural or abdominal effusions (pleural effusions develop slowly and only rarely cause respiratory or hemodynamic distress), hoarse voice, and slow speech Geriatrics Essentials: Hypothyroidism can differ significantly in older patients. Although secondary hypothyroidism is uncommon, its causes often affect other endocrine organs controlled by the Hypothalamic-Pituitary Relationships . In a woman with hypothyroidism, indications of secondary hypothyroidism are a history of amenorrhea rather than menorrhagia and some suggestive differences on physical examination. Secondary hypothyroidism is characterized by skin and hair that are dry but not very coarse, skin depigmentation, only minimal macroglossia, atrophic breasts, and low blood pressure. Also, the heart is small, and serous pericardial effusions do not occur. Hypoglycemia is common because of concomitant adrenal insufficiency or growth hormone deficiency. Myxedema coma is a life-threatening complication of hypothyroidism, usually occurring in patients with a long history of hypothyroidism. Its characteristics include coma with extreme hypothermia (temperature 24° to 32.2° C), areflexia, seizures, and respiratory depression with carbon dioxide retention. Severe hypothermia may be missed unless low-reading thermometers are used. Rapid diagnosis based on clinical judgment, history, and physical examination is imperative, because death is likely without rapid treatment. Precipitating factors include illness, infection, trauma, drugs that suppress the central nervous system, and exposure to cold. 