45 INFERTILITY, MALE General Discussion Infertility, defined as the inability to conceive after 1 year of unprotected intercourse, affects 15% of couples. Half of these couples have a component of…

44 INFERTILITY, FEMALE General Discussion Infertility affects one couple in six and becomes more common with increasing age. Clinical evaluation of infertility is indicated if a pregnancy has not occurred…

43 HYPOTHYROIDISM General Discussion Hypothyroidism usually results from decreased thyroid hormone production and secretion by the thyroid gland. Hypothyroidism can either be primary or central, which involves the pituitary gland…

41 HYPOKALEMIA General Discussion Hypokalemia is defined as a serum potassium level less than 3.6 mEq per liter. Hypokalemia has been associated with an increased risk of hypertension, ischemic stroke,…

38 HYPERTENSION General Discussion The relationship between blood pressure and the risk of cardiovascular disease is continuous, consistent, and independent of other risk factors. As the blood pressure rises, so…

40 HYPOGLYCEMIA General Discussion Symptoms of hypoglycemia begin at plasma glucose levels of approximately 60 mg/dL, and impairment of nervous system function begins at approximately 50 mg/dL. Clinical hypoglycemia is…

39 HYPERTHYROIDISM General Discussion Hyperthyroidism is a hypermetabolic state that results from excess synthesis and release of thyroid hormone, usually from the thyroid gland. The overall incidence of subclinical and…

37 HYPERNATREMIA General Discussion Hypernatremia is defined as a serum sodium concentration exceeding 145 mEq/L. In contrast to hyponatremia, which usually results from a defect in renal water handling, the…

35 HYPERCOAGULABLE STATES General Discussion Hypercoagulable conditions are classified as primary (an inherited condition) or secondary (an acquired state). The inherited disorders include factor V Leiden, prothrombin G20210A gene mutation,…