A diagnosis of primary Sjögren’s syndrome is often made on the basis of a classic triad of symptoms: dryness of the mouth and eyes, fatigue, and pain. Systemic complications, which are present in 30 to 40% of patients, may provide the first clues to the disease.
The American Academy of Sleep Medicine defines insomnia as the subjective perception of difficulty with sleep initiation, duration, consolidation, or quality that occurs despite adequate opportunity for sleep, and that results in some form of daytime impairment.
Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown cause that is characterized pathologically by an inflammatory and fibrotic process centered on the epithelium, leading to diffuse biliary stenosis and increased wall thickness throughout the intra- and extra-hepatic biliary trees.
The autosomal recessive inherited primary hyperoxalurias types I, II and III are caused by defects in glyoxylate metabolism that lead to the endogenous overproduction of oxalate.
The finding of hypercalcemia on routine biochemical testing or in the evaluation of postmenopausal women with osteoporosis is typically the initial clue to the diagnosis of primary hyperparathyroidism. The total serum calcium level, which combines both the free and albumin-bound components of circulating calcium, should be adjusted for the level of albumin. Measurement of ionized calcium may be useful in selected cases, such as in patients with hyperalbuminemia, thrombocytosis, Waldenström’s macroglobulinemia, and myeloma; these patients may have elevated levels of total serum calcium, but normal levels of ionized serum calcium (artifactual hypercalcemia).