Hyponatremia the underlying cause of hyponatremia. A blood test demonstrating a serum sodium less than 135 mmol/L is diagnostic for hyponatremia. The history and physical exam are necessary to help determine if the patient is hypovolemic, euvolemic, or hypervolemic, which has important implications in determining the underlying cause. An assessment is also made to determine if the patient is experiencing symptoms from their hyponatremia. These include assessments of alertness, concentration, and orientation. False hyponatremia, also known as spurious, pseudo, hypertonic, or artifactual hyponatremia is when the lab tests read low sodium levels but there is no hypotonicity. In hypertonic hyponatremia, resorption
Human blood group systems are expressed in a letter or two, which may be a plus or a minus, a smaller number of people express their blood type in an extensive series of letters in addition to their "AB±" type designation. For example, the h/h blood group, also known as Oh or the Bombay blood group, is a rare blood type. Human blood group systems The term human blood group systems is defined by International Society of Blood Transfusion as systems in the human species where cell-surface antigens—in particular, those on blood cells—are "controlled at a single gene locus or by two or more