Clinical Chemistry Tests

Sodium

fluid balance; high means dehydration, diabetes insipidus, low means GI loss from vomiting or diarrhea

Potassium

muscle contraction; high means shock, circulatory failure, renal disease, low means vomiting or diarrhea, diuretic use

Chloride

mirrors sodium concentrations; high is dehydration, low means low blood sodium, vomiting

Carbon dioxide

buffers blood; high is metabolic alkalosis, low is metabolic acidosis

Anion gap

high could mean ketoacidosis

Calcium

bone formation and blood clotting, nerve and muscle function; high could be hyperparathyroidism, low could be hypoparathyroidism, VitD deficiency, kidney disease

Phosphorus/Phosphate

bone metabolism, energy production, nerve and muscle function; high means renal insufficiency, VitD overdose, low means overuse of diuretics or antacids, hyperparathyroidism

Magnesium

essential for many enzymes to function, follow up test for low Ca or K; high could be renal disease, eclampsia, false high due to hemolysis, low means malabsorption, pancreatitis, diarrhea, alcoholism

Iron

oxygen transport, enzyme pathways; low means iron-poor diet, loss of blood, anemia

glucose

tests for glucose and metabolic state; low= insulin excess, starvation, adrenal insufficiency

vitamin B12

required for RBC function, identifies a deficiency when low iron and large RBC are present; high = some leukemias, low= malnutrition, malabsorption, pernicious anemia

folic acid

required for RBC function, determines cause of macrocytic anemia; high= pernicious anemia, low= malnutrition, malabsorption

total bilirubin

breakdown product of Hgb, assess liver function; raised means hepatitis, cirrhosis, hemolytic disease, obstruction of biliary or hepatic ducts

direct bilirubin(conjugated)

water soluble, tests the livers ability to conjugate bilirubin and excrete it; raised means obstruction of biliary or hepatic ducts

indirect bilirubin(unconjugated)

fat soluble, product of Hgb breakdown; difference between the total and direct forms; high means hereditary conditions

neonatal bilirubin

measured to determine if intervention is needed; raised means hemolysis of RBC, kernicterus(jaundice)

lactic acid

released under anaerobic energy production(from muscles), evaluates reason for SOB, muscle weakness; high means shock, muscle fatigue, diabetic ketoacidosis, tissue hypoxia, meningitis

uric acid

waste product from purine breakdown(DNA), evaluates joint inflammation, chemo/radiation treatments; high means gout, kidney disease, leukemia

creatinine

muscle breakdown waste product, evaluates kidney function; high means kidney dysfunction

urea nitrogen(BUN)

protein breakdown byproduct formed in the liver, ordered with creatinine to evaluate liver function, monitor dialysis patients; high means kidney dysfunction, stress, high protein diet, low means low protein diets or liver disease

Ammonia

waste product of AA breakdown, evaluates disorientation, confusion, and comas; high means severe liver disease, cirrhosis, severe hepatitis

TSH

made by pituitary gland, maintains T3 and T4 levels, screens for thyroid disease

Thyroxine (T4) and Triiodothyronine (T3)

control energy production in tissues, follow up after TSH to measure either total hormone or free hormones

estrogen

produced by the ovaries, evaluates cause of infertility and assess menopause

testosterone

male secondary sex characteristics, female estradiol(major female sex hormone), evaluates infertility or ED in adult males, delayed puberty in boys, virilization in females

Beta-human chorionic gonadatropin

protein produced by the placenta, used to confirm pregnancy

Total protein, serum/plasma

screening test; high means dehydration, infection, lowered means protein loss(from kidney or GI tract), liver disease, malnutrition

urine protein

evaluate kidney function, often pts taking nephrotoxic drugs; high= kidney failure(nephrotic syndrome), diabetes

CSF protein

in cerebrospinal fluid, investigates possible diseases of the nervous system; meningitis, tumors of the brain, multiple sclerosis

Albumin, serum/plasma

major protein in blood made in the liver, general indicator of health and nutritional status; high= dehydration, infection, malignancy, low= starvation, burns, kidney disease, liver disease

Albumin urine/microalbumin

monitors kidney functioning screen for early stages of kidney dysfunction

globulins

proteins in the blood other than albumin; high means infection, multiple myeloma, low means leukemia and immunosuppression

prealbumin(transthyretin)

unrelated to albumin, Vit A transport, nutritional marker, not affected by hydration status; low means liver disease, inflammation

ferritin

iron storage protein found primarily inside cells

transferrin

primary protein for iron transport, tests for iron status

total iron-binding capacity(TIBC)

max amount of iron that can be transported by transferrin in the blood

unsaturated iron-binding capacity(UIBC)

reserve capacity of transferrin for additional iron transport, used to monitor treatment for iron toxicity

haptoglobin

binds and transports free hemoglobin that is released from destroyed RBC, distinguishes hemolytic anemia from other anemias

Ceruloplasmin

protein that binds and transports copper, used to detect diseases of copper metabolism(Wilson’s disease)

Alanine aminotransferase (ALT)

found in liver, assess liver disease, more specific for liver diseases than AST

Aspartate aminotransferase(AST)

widely present in tissue especially liver, heart, and skeletal muscle, assesses liver disease

alkaline phosphatase(ALP)

found in many tissues, assessment of bone diseases and liver diseases

Gamma glutamyl-transferase(GGT)

very sensitive to indicator of any liver disorder, assess liver disease or damage; biliary obstruction, alcoholic liver disease

Lactate dehydrogenase(LD)

general indicator of tissue damage; heart attack, liver disease, lung disease, trauma

creatine kinase(CK)

muscle enzyme, indicator of muscle damage; high means muscle damage, extreme exercise, trauma, low means very low muscle mass

amylase

digestive enzyme secreted by salivary glands and pancreas, breaks down starches; diagnoses pancreatitis

lipase

digestive enzyme secreted by pancreatic and salivary glands, breaks down triglycerides; diagnoses pancreatitis

pseudocholinesterase or cholinesterase activity

enzymes that react with succinylcholine(muscle relaxants used in surgery), used if genetic deficiency is suspected or insecticide poisoning is suspected

Prostate-specific antigen(PSA)

prostate cancer; screening asymptomatic pts, confirm diagnosis, monitor therapy, determine recurrence

Carcinoembryonic antigen(CEA)

colorectal, lung, breast, liver, pancreas, and bladder cancers; monitors treatment and determines recurrence

cancer antigen 125(CA 125)

ovarian cancer; confirm diagnosis, monitor treatment, determine recurrence

cancer antigen 15-3(CA 15-3)

breast and some ovarian cancers; stage the disease, monitor treatment, determine recurrence

Alpha-fetoprotein(AFP)

liver, ovarian, and testicular cancers; monitor treatment, determines recurrence

Glycated hemoglobin(HbA1c)

hgb with glucose covalently bound; in diabetics, good estimate of glucose control over a 3 month period

troponin I and troponin T

diagnosis of heart attack

Rheumatoid factor(RF)

human IgM autoantibody in rheumatoid arthritis pts

C-reactive protein(CRP)

produced in response to an infection or inflammatory process; detect severity of inflammatory diseases like inflammatory bowel syndrome

high-sensitivity CRP

usually measured with a lipid panel to evaluate cardiovascular risk

B-type natriuretic peptide(BNP) and NT-proBNP

comes from a protein made in heart cells, helps regulate blood volume, NT-proBNP is an inactive peptide; tests for either BNP or NT-proBNP to detect or evaluate cardiac failure

antistreptolysin O (ASO)

presence of Ab to streptolysin O(toxin made by S.pyogenes)