Hyponatremia lead to increased reaction time and falls. Hyponatremia, by interfering with bone metabolism, has been linked with a doubled risk of osteoporosis and an increased risk of bone fracture. The specific causes of hyponatremia are generally divided into those with low tonicity (lower than normal concentration of solutes), without low tonicity, and falsely low sodiums. Those with low tonicity are then grouped by whether the person has high fluid volume, normal fluid volume, or low fluid volume. Too little sodium in the diet alone is very rarely the cause of hyponatremia. Both sodium and water content increase: Increase in sodium
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