Tests starting with the letter N
Laboratory Test Guide: Tests Beginning with the Letter "N"
A complete list of all tests beginning with the letter "N" performed at Egemed Hospitals' Medical Laboratories is provided below. To help our patients understand these tests, a brief medical description of each test group and its intended laboratory use are clearly stated.
Biochemistry, Cardiology, and Endocrinology
24-Hour Urine Norepinephrine
Description: This test measures the levels of normetanephrine—a byproduct formed during the breakdown of norepinephrine, a hormone that raises blood pressure in the body—by collecting a 24-hour urine sample.
Purpose: Used in the diagnosis of pheochromocytoma (a tumor of the adrenal gland), which manifests as sudden spikes in blood pressure, palpitations, and episodes of sweating.
NT-ProBNP
Description: This is the blood level of a specific protein (peptide) released by heart cells and entering the bloodstream when the heart muscle is overstretched or strained.
Purpose: This test is ordered on an emergency or routine basis to confirm a diagnosis of "heart failure" in patients presenting with shortness of breath and to stage the severity of heart failure.
Immunology, Hematology, and Neurology Panels
NEUROMYELITIS OPTICA (NMO/AQP4) IgG
Description: This test detects destructive autoantibodies that the immune system mistakenly produces against the water channels (aquaporin-4) in the optic nerves and spinal cord.
Objective: It is of vital importance to distinguish Neuromyelitis Optica (NMO)—a condition characterized by vision loss and paralysis—from Multiple Sclerosis (MS).
NK Cell Panel
Description: This test measures the number of Natural Killer (NK) cells—the most aggressive soldiers in our immune system that fight viruses and cancer cells—in the blood using flow cytometry.
Purpose: To investigate severe immunodeficiencies, identify the immunological causes of recurrent pregnancy loss (miscarriage), and diagnose certain types of blood cancer.
Microbiology, Culture, and Molecular Testing
Nasal Swab
Description: This procedure involves smearing a swab taken from the nasal mucosa onto a slide and examining it under a microscope using special stains to observe cells (particularly eosinophils).
Purpose: To quickly determine whether the patient’s symptoms of a runny nose and nasal congestion are caused by an allergic reaction (allergic rhinitis) or by a bacterial infection.
Nasopharyngeal Culture
Description: This involves collecting a sample using special swabs inserted through the nostrils to reach the nasopharynx and then culturing the sample on laboratory media.
Purpose: To identify the causative agents of severe respiratory bacterial infections, such as whooping cough, diphtheria, meningitis, and pneumonia, and to identify carriers.
NEISSERIA GONORRHEA PCR
Description: This test involves searching for the direct genetic (DNA) sequence of the "N. gonorrhoeae" bacterium—which causes gonorrhea—in a swab sample taken from the urine or genital area.
Objective: To detect gonorrhea—a sexually transmitted infection that can sometimes progress asymptomatically and lead to infertility—with gold-standard sensitivity (PCR).
NOROVIRUS ANTIGEN, Stool
Description: This test involves the rapid detection of cellular proteins (antigens) associated with the highly contagious and rapidly spreading norovirus using rapid testing methods on a stool sample.
Objective: To identify the source of outbreaks of nausea, severe vomiting, and diarrhea (stomach flu) in order to bring the outbreak under control and prevent the unnecessary use of antibiotics.