BNP (B-type Natriuretic Peptide)
BNP (B-type Natriuretic Peptide) Overview BNP is a hormone secreted primarily by cardiac ventricular myocytes in response to myocardial stretch and wall stress. It promotes natriuresis, diuresis, and vasodilation to reduce cardiac preload and afterload. Elevated levels indicate heart failure, acute coronary syndrome, or pulmonary embolism, while low levels suggest non-cardiac dyspnea. It is clinically […]
Beta-Hydroxybutyrate
Beta-Hydroxybutyrate Overview Beta-hydroxybutyrate (βHB) is the primary ketone body produced during ketogenesis in the liver, measuring the level of this molecule in blood as an indicator of ketosis or ketoacidosis. It serves as an alternative energy source for tissues like the brain during carbohydrate deprivation or metabolic stress. Elevated levels indicate diabetic ketoacidosis (DKA), alcoholic […]
Blood Urea Nitrogen (BUN)
Blood Urea Nitrogen (BUN) Overview Blood urea nitrogen (BUN) measures the amount of urea nitrogen, a waste product from protein metabolism, in the blood. It reflects kidney function in excreting urea, hydration status, and protein catabolism rates. Elevated levels may indicate kidney impairment, dehydration, gastrointestinal bleeding, or high protein intake, while low levels can signal […]
Bilirubin (Direct)
Bilirubin (Direct) Overview Direct bilirubin measures the conjugated fraction of bilirubin in the blood, which is processed by the liver and excreted into bile. It indicates liver conjugation capacity and biliary excretion efficiency. Elevated levels suggest intrahepatic or extrahepatic cholestasis, Dubin-Johnson syndrome, or Rotor syndrome, while low levels are typically insignificant. It is clinically useful […]
Bilirubin (Total)
Bilirubin (Total) Overview Total bilirubin measures the combined levels of unconjugated (indirect) and conjugated (direct) bilirubin in the blood, a byproduct of red blood cell breakdown processed by the liver. It reflects liver function, bile flow, and hemolysis rates. Elevated levels may indicate liver diseases like hepatitis or cirrhosis, biliary obstruction, or hemolytic anemia, while […]
Cortisol
Cortisol Overview Cortisol is a glucocorticoid hormone produced by the adrenal cortex that helps regulate metabolism, immune responses, blood pressure, and the body’s stress response. It is secreted in a diurnal pattern, with peak levels in the early morning and a nadir around midnight. Elevated levels may indicate Cushing syndrome, chronic stress, depression, or exogenous […]
Creatinine
Creatinine Overview Creatinine measures a waste product from creatine phosphate breakdown in muscle metabolism, filtered by the glomeruli with minimal tubular reabsorption. Serum levels reflect glomerular filtration rate (GFR), serving as an endogenous marker of kidney function. Elevated levels indicate impaired renal clearance from acute or chronic kidney disease, while low levels may reflect reduced […]
Calcium
Calcium Overview Calcium measures the primary divalent cation essential for bone mineralization, muscle contraction, nerve transmission, and blood coagulation. It circulates bound to albumin, complexed with anions, or as ionized free calcium, with total calcium reflecting overall status while ionized provides physiological activity. Elevated levels (hypercalcemia) may indicate hyperparathyroidism, malignancy, or vitamin D excess, while […]
C-Reactive Protein (CRP)
C-Reactive Protein (CRP) Overview C-reactive protein (CRP) measures an acute-phase protein produced by the liver in response to inflammation, infection, or tissue injury. It binds to phosphocholine on damaged cells and microbes, activating complement and promoting phagocytosis. Elevated levels indicate acute or chronic inflammation, infection, cardiovascular disease risk, or autoimmune conditions, while low levels suggest […]
Cholesterol (Total)
Cholesterol (Total) Overview Total cholesterol measures the sum of low-density lipoprotein (LDL),high-density lipoprotein (HDL), and very low-density lipoprotein (VLDL)cholesterol in blood. It serves as a key indicator of lipid metabolism andcardiovascular risk. Elevated levels indicate dyslipidemia and increasedatherosclerosis risk, while low levels may occur in malnutrition,hyperthyroidism, or liver disease. It is clinically useful for cardiovasculardisease […]
Dehydrogenase (LDH)
Dehydrogenase (LDH) Overview Lactate dehydrogenase (LDH) is an intracellular enzyme that catalyzes the interconversion of lactate and pyruvate during anaerobic glycolysis and is present in many tissues, including heart, liver, muscle, kidney, lung, and red blood cells. Total LDH in blood reflects cell turnover and tissue injury rather than a single organ’s function. Elevated LDH […]
Dopamine
Dopamine Overview Dopamine is a catecholamine neurotransmitter and hormone that plays key roles in motor control, reward, cognition, and regulation of prolactin and cardiovascular tone. It is synthesized from tyrosine in dopaminergic neurons and adrenal medulla cells, then metabolized mainly to homovanillic acid (HVA) and 3,4‑dihydroxyphenylacetic acid (DOPAC). Elevated circulating or urinary dopamine (and its […]