Topics: water, sodium, kidneys, Acid–base disturbances, potassium, Calcium, phosphate, magnesium, hypothalamus, pituitary gland, adrenal cortex, reproductive system, Pregnancy, infertility, thyroid function, Carbohydrate metabolism, Plasma lipids, lipoproteins, nutrition, Vitamins, trace elements, trace metals, gastrointestinal tract, Liver disorders, gallstones, Plasma enzymes, clinical enzymology, Purine, urate metabolism, Cardiovascular disease, Cerebrospinal fluids, pleural fluids, ascitic fluids, Therapeutic drug monitoring, poisoning, Inborn errors of metabolism, Genetics, deoxyribonucleic acid-based technology, Patient sample collection, use of the laboratory, Point-of-care testing