Chloride (CI-) test

      Chloride, an important negatively charged electrolyte,Chloride is present in the extracellular spaces in combination with sodium and hydrogen. Chloride has two main bodily functions :1-Chloride help to control the distribution of water between the cells and blood plasma, Chloride  help to maintain the acid-base balance in the body.

Normal Range of  Chloride
90-110 mEq/L

Variations from Normal. Variations in chloride levels must always be considered in relation to other electrolytes, particularly sodium and bicarbonate.
An increase in plasma chloride will correspond to an increase in sodium levels or a decrease in plasma bicarbonate levels. Measuring chlorides can be helpful in diagnosing acid-base and water balance disorders.
Increases in plasma chloride levels are seen in dehydration, eclampsia, Cushing's syndrome, and anemia. Plasma chloride is decreased with severe vomiting, diarrhea, burns, and heat exhaustion. Other diseases and syndromes that result in chloride deficits include ulcerative colitis, Addison's disease, and diabetic acidosis.

Interfering Circumstances of Chloride . Drugs that may cause an increase in chloride levels are androgens, cortisone preparations, estrogens, and nonsteroidal anti-inflammatory drugs. Decreased chloride levels can be associated with corticosteroids, hydrocortisone, and diuretics containing thiazide or mercury.

Magnesium (Mg+) test

      The bulk of magnesium is combined with calcium and phosphorus in the bones, with very small amounts present in the bloodstream . Magnesium is necessary for muscular contraction, carbohydrate metabolism, and protein synthesis . It is usually filtered by the kidney through the glomerulus, and reabsorbed into the bloodstream by the renal tubule. Magnesium levels can be used as an indicator of metabolic activity and renal function. Since
magnesium is present in a variety of foods, a normal diet will maintain the body's magnesium supply.

Normal Range
1.6-3.0 mEq/L

Variations from Normal. An increase in plasma magnesium, hypermagnesemia, is usually caused by renal dysfunction or failure. Other diseases or syndromes associated with increased magnesium levels include hypothyroidism, Addison's disease, and dehydration. Excessive ingestion of magnesium via antacids, such as milk of magnesia, will also cause an increase in plasma magnesium.
Hypomagnesemia, decreased plasma magnesium, is usually due to
some type of chronic dietary or intestinal absorption problem. Diseases such as ulcerative colitis, chronic alcoholism, chronic pancreatitis, and chronic diarrhea will exhibit decreased magnesium levels. Other situations that result in hypomagnesemia include toxemia of pregnancy, hyperthyroidism, hypoparathyroidism,
cirrhosis of the liver, and excessive secretion of the hormone
aldosterone .
Magnesium deficiencies can be corrected by the proper administration of magnesium sulfate . Early symptoms of magnesium deficit include muscle cramps, tremors, and insomnia. It should be noted that decreases in urinary magnesium may be detected before decreases in plasma magnesium.
Low levels of calcium and potassium may mask the presence of hypomagnesemia.

Interfering Circumstances. A variety of medications can interfere with laboratory measurement of magnesium levels. Prolonged treatment involving lithium, magnesium products such as antacids and laxatives, and salicylate products such as aspirin will cause a false increase in plasma magnesium levels. This is particularly possible in the face of renal dysfunction. Administration
of calcium gluconate, which is used to replenish the body's
calcium reserves, can also interfere with testing methods and cause a false result that indicates a decreased magnesium level.

Calcium (Ca+) test

       Approximately 98% of all calcium is stored in bones and teeth. Calcium

that is present in the bloodstream circulates in the ionized, or free state, and

in a protein-bound form with albumin. It is the ionized form of calcium that

is used in bodily processes such as muscular contraction, cardiac functioning,

hormone secretion, cell division, and the transmission of nerve impulses.

Ionized calcium is essential for blood coagulation .

Normal Range

Total plasma calcium

9.0-10.5 mg/dl

Free calcium

3.9-4.6 mg/dl

    Variations from Normal. Hypercalcemia, increased plasma calcium, is associated

with many diseases but is most clinically significant in its association

with cancer. The most common cause of increased calcium in the

blood is metastatic bone disease . Cancers of the lung, breast, thyroid, kidney,

and testes are likely to metastasize to bone. Hodgkin's disease, multiple

myeloma, and leukemia may also cause hypercalcemia . Other disorders

or conditions associated with increased calcium levels are hyperparathyroidism,

Paget's disease of bone, prolonged immobilization, and Addison's

disease.

       Since much of the plasma calcium is bound to albumin, decreased

plasma calcium levels, hypocalcemia, can be related to a lowered plasma albumin

level. Once this possibility has been eliminated, hypocalcemia can be

indicative of hypoparathyroidism and renal failure . Vitamin D deficiencies

and malabsorption associated with sprue, celiac disease, and pancreatic

dysfunctions contribute to decreased plasma calcium levels. Since calcium is

essential for clotting, any condition that decreases the amount of ionized calcium

can subsequently lead to coagulation and hemostasis problems.

Interfering Circumstances. Certain dietary considerations can interfere

with accurate plasma calcium test results . Vitamin D intoxication or excessive

milk ingestion, defined as three quarts of milk per day, can cause an increase

in plasma calcium.

      Prescription and over-the-counter drugs such as heparin, magnesium

salts, oral contraceptives, aspirin, and corticosteroids and excessive use of

laxatives may cause a decrease in plasma calcium. Drugs that influence an

increase of plasma calcium include lithium, vitamin D, thiazide diuretics,

thyroid hormone, and hydralazine, an antihypertensive medication.