Laboratory Test Definitions
Understanding laboratory medicine can be quite daunting. The use of confusing acronyms, to understanding reference ranges can make it difficult to make informed health choices. When you have questions, you should always consult the ordering healthcare provider first.. In addition, for general questions, may we recommend Lab Test Online.
Fasting: The composition of blood is altered after meals by nutrients being absorbed into the blood stream. Postprandial blood may not be suitable for a number of tests. An overnight fast is preferable to ensure that a patient is in a basal metabolic state. In general, 10 to 12 hours is best. Fasting includes abstaining from coffee, tea and sugar-free products. However, since dehydration can alter laboratory results, the drinking of water is strongly encouraged.
CBC (complete blood count): is a profile of tests rather than a single test. It is a standard, broadly inclusive, automated test for the evaluation of RBC (red blood count), WBC (white blood count), and platelets.
The white blood cell differential is often used as part of a complete blood count (CBC) as a general health check. It may be used to help diagnose or monitor diseases and conditions that may affect one or more of the different types of White Blood Cells (WBC). The differential totals the number of each type to determine if normal proportions are present, and to see if any immature cells are seen. This information may help to diagnose a number of conditions including infection, inflammation, allergies, immune disorders, and bone marrow disorders.
A peripheral blood smear (peripheral blood film) is a glass microscope slide coated on one side with a thin layer of venous blood. The slide is stained with Wright’s stain, and examined under a microscope. This test is used in conjunction with a complete blood count. It is an aid in the evaluation of anemia, leukemia, infections, inflammatory states, and inherited disorders of red cells, white cells, and platelets.
Metabolic profiles: Are groups of tests utilized to evaluate basic metabolic functions. including renal (kidney) and hepatic (liver) function. They are standardized and automated.
Basic metabolic includes blood urea nitrogen (BUN), creatinine, glucose, calcium, and electrolytes (CO2, chloride, potassium and sodium).
Complete metabolic includes blood urea nitrogen (BUN), creatinine, glucose, calcium, and electrolytes (CO2, Chloride, Potassium and Sodium), alkaline phosphatase, alanine aminotransferase (ALT/SGPT), aspartate aminotransferase (AST/SGOT), total bilirubin, total protein.
Liver (Hepatic) Profile: includes alkaline phosphatase, alanine aminotransferase (ALT/SGPT), aspartate aminotransferase (AST/SGOT), total bilirubin, total protein, direct bilirubin.
Lipid Profiles are used to evaluate lipid status. High levels may be caused by inherited defects in lipoprotein metabolism, disease of the endocrine system, or by liver or renal disease. Cholesterol relates to coronary heart disease risk. Effective intervention is likely to benefit. A complete panel includes total cholesterol, triglycerides, HDL cholesterol, calc VLDL cholesterol, calc. LDL, and estimated coronary heart disease (CHD) risk factor.
Hemoglobin A1c test evaluates the average amount of glucose in the blood over the last 2 to 3 months. It does this by measuring the concentration of glycated (also often called glycosylated) hemoglobin A1C. Hemoglobin A1C is commonly used to monitor and manage diabetic patients.
An international expert committee that includes representatives from the American Diabetes Association (ADA), International Diabetes Federation (IDF), and European Association for the Study of Diabetes (EASD) has officially endorsed the use of HbA1c to diagnose or screen for diabetes. Patients do not need to be fasting. The recommended cut off values include: Normal <5.7%, Pre Diabetic 5.7% - 6.4 %, Diabetic >= 6.5%.
Fasting Plasma Glucose is the standard test for diabetes screening, and more economical than an A1c. The ADA recommendations include that a fasting blood glucose level between 100 and 125 mg/dl signals pre-diabetes. A person with a fasting blood glucose level of 126 mg/dl or higher has diabetes.
Prostate Specific Antigen (PSA) Is a glycoprotein produced exclusively by the cells lining the prostatic ducts and acini. Serum PSA measurement is not an absolute test for malignancy, but a screening test that should be used in conjunction with clinical evaluation and other diagnostic procedures.
Thyroid Stimulating Hormone (TSH) Used as a screening test for thyroid function. A normal result on a sensitive TSH assay is acceptable evidence of adequate thyroid replacement.
Vitamin D, 25-Hydroxy Is used to rule out Vitamin D deficiency. Values of Vitamin D vary with sunlight. There are also variations during the menstrual cycle, particularly at the time of ovulation. Vitamin D deficiency has been linked to numerous conditions.
Infectious Mononucleosis is an acute infectious disease of viral etiology. The most frequent symptoms include fever, sore throat, lymphadenopathy, anorexia & malaise, headache & myalgia, and splenomegaly. A diagnosis based on clinical history and symptoms alone may be difficult.
Misidentification with other non-related viral illnesses and bacterial diseases can occur. Infectious Mononucleosis (IM) is caused by Epstein-Barr virus, which is a member of the herpesvirus family. Traditional diagnosis of IM is based on the presence of heterophile antibodies. IM heterophile antibodies are acute phase IgM class, and present in 80-90% of acute IM cases.
Urinalysis is composed of four parts: specimen evaluation, physical tests, chemical examination and sediment examination. The Urinalysis is a panel of tests that include Color, Appearance, Specific Gravity, pH, Protein, Glucose, Ketone, Occult Blood, Leukocyte Esterase, Nitrite, Bilirubin, and Urobilinogen. Microscopic evaluation is performed based on criteria.
Direct Microscopic Evaluation may be performed on Urine, Stool, Vaginal secretions, and skin.
Urine sediment: finding and recognizing important formed elements such as cells, microorganisms, parasites and neoplastic cells provides the physician with the information pertinent to the diagnosis and management of renal tract disease.
Vaginal discharge provides a simple rapid method for the detection of Trichomonas vaginalis, yeast, WBC’s, and “Clue Cells” associated Bacterial Vaginosis.
KOH Is used to determine the presence of fungal elements in patient specimens, including skin, nails, hair, vaginal discharge, and exudates from abscesses, sinus tracts, and other mucous membranes
Stool Smears are a direct, rapid evaluation of stool on patient’s presenting with acute diarrhea, to test for the presence of poylmorphonuclear leukocytes. The presence of o polymorphonuclear leukocytes helps to separate out treatable bacterial disease and specimens suitable for culture.
Pregnancy (hCG): The test is a qualitative immunoassay for the detection of human Chorionic Gonadotropin (hCG) in urine for the early detection of pregnancy. Human Chorionic Gonadotropin is a hormone produced by the placenta shortly after implantation. Since hCG is present in the serum and urine of pregnant women, it is an excellent marker confirming pregnancy.
Rapid Strep Testing is a, qualitative immunoassay for the detection of Strep A antigen from a throat swab. The traditional identification procedures for Group A Streptococci involve isolation of viable organisms by culture techniques that can take 24 to 48 hours. Rapid identification and early antibiotic therapy of Group A Streptococcus appear to be the best means of preventing medical complications and reducing the spread of disease.
Identification of Group A Streptococcus is done to aid in diagnosis and treatment of infections including pharyngitis, respiratory Infection, impetigo, endocarditis, menigitis, puerperal Sepsis, and arthritis.
Rapid Influenza allows for the qualitative detection of influenza type A and type B antigens directly form a nasal swab. This test is intended for use as an aid in the rapid diagnosis of acute influenza virus infection.
Influenza is a highly contagious, acute, viral infection of the respiratory tract. The causative agents of the disease are immunologically diverse, single-strand RNA viruses known as influenza viruses. There are three types of influenza viruses: A, B, and C based on different soluble nucleoprotein antigens. Type A viruses are the most prevalent and are often associated with most serious epidemics. Type B viruses produce a disease that is generally milder than that caused by type A. Type C virus has never been connected with a large epidemic of human disease. Both type A and B virus can circulate simultaneously in a population, but usually one type is dominant during a given season.
HIV is a sexually transmitted infection caused by a human retrovirus. It can also be spread by contact with infected blood. By damaging your immune system, HIV interferes with your body’s ability to fight other organisms that cause disease.
The Centers for Disease Control and Prevention (CDC) estimates that approximately 1.1 million persons are living with HIV in the United States. This number is expected to continue to increase over time, as antiretroviral treatments prolong the lives of those who are infected and more people become infected with HIV than die from the disease each year. As the number of people living with HIV—or HIV prevalence—grows, so does the opportunity for HIV transmission to others.
Regular screening is vital not only leading to earlier treatment, better health outcomes, and longer life, but to prevention of the disease. Increasing the number of HIV-infected people who are aware of their status is integral to prevention. The testing we offer requires blood.
Syphilis is a sexually transmitted infection (STI) caused by the bacterium Treponema pallidum. It has often been called "the great imitator" because so many of the signs and symptoms are indistinguishable from those of other diseases. Rapid plasma reagin (RPR) is a test for this disease. It is easy to cure in early stages, and because of this effective treatment, it is important to be screened regularly. The testing requires blood.
Neisseria gonorrhea manifests as acute urethritis in males and as cervicitis in females. Detection and treatment of these individuals is critical because if it is left untreated, gonorrhea can result in serious complications including pelvic inflammatory disease, sterility and ectopic pregnancy. A molecular assay is used for the detection. Testing may be performed from specimens including urine, endocervical swabs, and Thin Prep (PAP) specimens. It is usually performed in conjunction with Chlamydia testing. Patients must abstain from urination for one hour before the specimen collection.
Chlamydia trachomatis is recognized as the leading agent of sexually transmitted disease worldwide. In the United States more than 4 million cases of Chlamydia infection are reported annually. A molecular assay is used for the detection. Testing may be performed from specimens including urine, endocervical swabs, and thin prep (PAP) specimens. It is usually performed in conjunction with Gonorrhea testing. Patients must abstain from urination for one hour before the specimen collection.