Use the A-Z list to browse more than 6,000 health-related topics in our library. Clicking on a term opens the definition and, in most cases, links to more information.
"N acetyl d Glucosamine" is more commonly referred to as "Glucosamine" in the medical community. Glucosamine
Also Known As: "Glucosamine HCL, Glucosamine Sulfate"
A form of amino sugar that is believed to play a role in cartilage formation and repair, and which is available as a nutritional supplement. More Information on Glucosamine: Arthritis
"N Laurylsphingosine Deacylase Deficiency" is more commonly referred to as "Farber Disease" in the medical community. Farber Disease
Also Known As: "Ceramidase Deficiency, Farber Lipogranulomatosis, Acid Ceramidase Deficiency"
A rare, inherited disease of the metabolism that commonly results in joint pain and inflammation. More Information on Farber Disease: Fibromyalgia & Pain Disorders
"N Methyl D Aspartate Receptor Antagonists" is more commonly referred to as "NMDAs" in the medical community. NMDAs
A medication used in the treatment of moderate to severe Alzheimer's disease. It works by regulating glutamate (a neurotransmitter involved in information storage, retrieval and processing). Too much glutamate can damage nerve cells. More Information on NMDAs: Alzheimer's & Dementia
A pain reliever and anti-inflammatory medication that belongs to the class of medications called non-steroidal anti-inflammatory drugs (NSAIDs). More Information on Nabumetone: Pain Medications
"Nad+" is more commonly referred to as "Nicotinamide Adenine Dinucleotide" in the medical community. Nicotinamide Adenine Dinucleotide
Also Known As: "Nad+/Nadh"
A coenzyme derived from the B vitamin niacin that becomes NADH when it accepts a pair of high-energy electrons for transport in cells. More Information on Nicotinamide Adenine Dinucleotide: Vitamins
"Nad+/Nadh" is more commonly referred to as "Nicotinamide Adenine Dinucleotide" in the medical community. Nicotinamide Adenine Dinucleotide
Also Known As: "Nad+"
A coenzyme derived from the B vitamin niacin that becomes NADH when it accepts a pair of high-energy electrons for transport in cells. More Information on Nicotinamide Adenine Dinucleotide: Vitamins
Infection by an Ameba found in water and soil called Naegleria fowleri. It infects humans, typically when the ameba enters the nose while a person is underwater and travels to the brain and spinal cord. Infection is rare, but usually fatal. More Information on Naegleria Infection: Infectious Disease Basics
"Nafcillin" is more commonly referred to as "Penicillins" in the medical community. Penicillins
Also Known As: "Oxacillin, Ticarcillin, Dicloxacillin, Amoxicillin, Cloxacillin, Carbenicillin, Ampicillin"
A class of antibiotics, medications that kill or slow the growth of harmful microorganisms, such as bacteria. They have no effect on viruses. Examples include penicillin, amoxicillin, ampicillin and dicloxacillin, among others. More Information on Penicillins: Cold & Infections Medications
"NAFLD" is more commonly referred to as "Nonalcoholic Fatty Liver Disease" in the medical community. Nonalcoholic Fatty Liver Disease
Also Known As: "Nonalcoholic Steatohepatitis, NASH"
Inflammation and excessive fat buildup in the liver that is not associated with alcohol use. More Information on Nonalcoholic Fatty Liver Disease: Liver, Pancreas & Biliary
Infection with fungi that live on the dead tissues of the nails. People with nail injuries are at increased infection risk. Growth of new, non-infected nails cures the infection, and can take up to a year. Relapse is common. More Information on Nail Fungus: Skin Related Infections
A disorder characterized by discolored, pitted and dry nails that commonly occurs in people with psoriasis (chronic disorder marked by red patches of skin covered with scales). More Information on Nail Psoriasis: Psoriasis & Autoimmune Skin
"Nalbuphine" is more commonly referred to as "Anileridine" in the medical community. Anileridine
Also Known As: "Levorphanol, Buprenorphine, Oxymorphone, Hydromorphone, Butorphanol, Pentazocine"
A type of narcotic analgesic, medications that reduce pain and most also reduce inflammation. They do not eliminate pain, but mask it by increasing the body's pain threshold. More Information on Anileridine: Pain Medications
An opioid receptor antagonist medication used to curb the cravings of addicts for drugs and alcohol. It blocks the effects of narcotics in the body and decreases cravings for alcohol. It is available by prescription only. More Information on Naltrexone: Alcohol & Substance Abuse
A nonprofit advocacy organization of consumers, families, and friends of people with severe mental illnesses. Founded in 1979, it works to achieve equitable services and treatment for Americans with mental illnesses.
"Nanism" is more commonly referred to as "Dwarfism" in the medical community. Dwarfism
Also Known As: "Disproportionate Short Stature"
Condition that usually results in an adult height of 4 feet, 10 inches or shorter. More than 200 types have been identified, many related to genetic or hormonal disorders. More Information on Dwarfism: Birth & Genetic Disorders
"Nanism-Constrictive Pericarditis Syndrome" is more commonly referred to as "Mulibrey Nanism Syndrome" in the medical community. Mulibrey Nanism Syndrome
A condition marked by slow or halted growth that includes abnormalities of the muscles, brain, eyes and liver. It also includes restrictive pericarditis (inflammation of the membrane around the heart), heart failure and other heart-related problems. More Information on Mulibrey Nanism Syndrome: Heart Injuries & Infections
"Naphazoline" is more commonly referred to as "Decongestants for Allergies & Asthma" in the medical community. Decongestants for Allergies & Asthma
Also Known As: "Pseudoephedrine"
Over-the-counter medications that shrink swollen nasal tissues to relieve symptoms of allergic rhinitis, nasal swelling, congestion and mucus secretion. More Information on Decongestants for Allergies & Asthma: Allergy & Asthma Drugs
A brand of nonsteroidal anti-inflammatory drugs (NSAIDs), medications that are commonly used to reduce pain and inflammation. More Information on Naprosyn: Heart Drug & Medication
A pain reliever and anti-inflammatory medication that belongs to the class of medications called non-steroidal anti-inflammatory drugs (NSAIDs). It is available both over-the-counter and by prescription. More Information on Naproxen: Pain Medications
A pain reliever and anti-inflammatory medication that belongs to the class of medications called non-steroidal anti-inflammatory drugs (NSAIDs). It is available both over-the-counter and by prescription. More Information on Naproxen Sodium: Pain Medications
A condition marked by a severely inflated sense of self-worth and extreme preoccupation with one's self. Other symptoms include a high need for admiration and a lack of empathy. It occurs more often in men than women. More Information on Narcissistic Personality Disorder: Personality Disorders
A neurological sleep disorder characterized by sudden and uncontrollable sleepiness and frequent daytime sleeping. The exact cause is unknown, but it may have a genetic component. There is no cure and treatment tries to manage symptoms. More Information on Narcolepsy: Sleep
"Narrowed Valve" is more commonly referred to as "Valvular Stenosis" in the medical community. Valvular Stenosis
A narrowing, stiffening, thickening, fusion or blockage of one or more valves of the heart, including the mitral valve and aortic valve on the left side, and the pulmonic valve and tricuspid valve on the right side. More Information on Valvular Stenosis: Heart Valve
"Narrowing of the Arteries" is more commonly referred to as "Atherosclerosis" in the medical community. Atherosclerosis
Also Known As: "Blockage of the Arteries, Hardening of the Arteries"
A disease in which the arteries harden and become narrowed due to the gradual build up of plaque on their inner walls. More Information on Atherosclerosis: Vascular Disease
The nose is the beginning of the upper respiratory tract, where air enters the body to begin the breathing process. It is also part of the olfactory system, which senses smells. Sinuses are air-filled pockets within the bones of the nose and face. More Information on Nasal & Sinus Function: Nose & Throat
Cancer in or around the nasal passages, symptoms of which may be confused with rhinosinusitis. Of the six sinuses, cancer of the maxillary sinus is the most common. More Information on Nasal Cancers: Head, Neck & Mouth Cancer
A hand-held device with a telescope that is used by medical professionals to see this inside of a patient's nasal cavities and sinuses. The slender devices may be straight or angled. It is used to diagnose conditions or during surgical procedures. More Information on Nasal Endoscope: Nose & Throat
A procedure in which a special telescope (nasal endoscope) is inserted into the nose and/or sinus cavities to allow physicians a view of these areas. Typically used for diagnosis, it may also be used to guide physicians during surgical procedures. More Information on Nasal Endoscopy: Nose & Throat
"Nasal Epithelium" is more commonly referred to as "Sinus Epithelium" in the medical community. Sinus Epithelium
Also Known As: "Nose Epithelium"
The lining of the paranasal sinus made up of many cells. Each of these cells has a cilium that can secrete mucus to keep the sinus cavity moist. Sinuses do not drain by gravity. Instead, the cilium of each cell secretes mucus in a defined pattern. More Information on Sinus Epithelium: Nose & Throat
"Nasal Meatus" is more commonly referred to as "Meatus" in the medical community. Meatus
Also Known As: "Middle Meatus, Nose Meatus, Inferior Meatus, Superior Meatus"
The spaces between the turbinates -- round structures within the outside walls of the nose that run along the length of the nasal cavities. They are named for the turbinates above them (superior, middle and inferior). More Information on Meatus: Nose & Throat
"Nasal Sinuses" is more commonly referred to as "Sinuses" in the medical community. Sinuses
Also Known As: "Sinus Cavities, Frontal Sinuses, Paranasal Sinuses, Maxillary Sinuses, Sphenoid Sinuses, Ethmoid Sinuses"
Air-filled cavities or packets located within the bones around the nose and face. They are named for the bones they inhabit: Maxillary (cheek), ethmoid (between the eyes), frontal (forehead) and sphenoid (middle of skull). More Information on Sinuses: Nose & Throat
Examination of nasal fluids for the presence of eosinophils, a white blood cell that can indicate an allergy. Patients blow their nose onto a plastic sheet. Fluids are transferred to a plastic slide and tested. More Information on Nasal Smear: Nose & Throat
Also Known As: "Antibiotic & Decongestant Nasal Sprays, Antihistamine Nasal Sprays, Anticholinergic Nasal Sprays, Decongestant Nasal Sprays, Lubricant Nasal Sprays"
Medications used to relieve nasal allergy and cold symptoms that are delivered in the form a fine mist directly into the nasal passages. More Information on Nasal Sprays: Nose & Throat
"Nasal Turbinates" is more commonly referred to as "Turbinates" in the medical community. Turbinates
Also Known As: "Superior Turbinates, Middle Turbinates, Nose Turbinates, Inferior Turbinates"
Three round structures inside each nasal cavity that run along the length of the nasal septum. They are named for their location superior (uppermost, near the bridge or the nose) middle and inferior (lowermost, near the nostrils). More Information on Turbinates: Nose & Throat
"NASH" is more commonly referred to as "Nonalcoholic Fatty Liver Disease" in the medical community. Nonalcoholic Fatty Liver Disease
Also Known As: "Nonalcoholic Steatohepatitis, NAFLD"
Inflammation and excessive fat buildup in the liver that is not associated with alcohol use. More Information on Nonalcoholic Fatty Liver Disease: Liver, Pancreas & Biliary
A feeding tube placed in the nose (a type of enteral nutrition). It may be used for people who are unable to get enough nutrients from their diet due to prolonged vomiting, diarrhea or other conditions. More Information on Nasoenteral Tube: Digestive Treatments
The process of inserting a tube through the nose and into the stomach or small intestine for such procedures as nasogastric lavage or aspiration. More Information on Nasogastric Intubation: Digestive Treatments
Also Known As: "Nasogastric Intubation, Intestinal Intubation"
The process of inserting a tube through the nose and into the stomach or small intestine for such procedures as nasogastric lavage or aspiration. More Information on Nasogastric or Intestinal Intubation: Digestive Treatments
A feeding tube placed in the nose (a type of enteral nutrition). It may be used for people who are unable to get enough nutrients from their diet due to prolonged vomiting, diarrhea or other conditions. More Information on Nasogastric Tube: Digestive Treatments
A duct that drains tears into a nasal structure called the inferior meatus (in the side of the nose wall). The explains why the nose becomes congested when a person cries. More Information on Nasolacrimal Duct: Nose & Throat
A cancer that develops in the nasopharynx, an area in the back of the nose toward the base of skull. It is a type of oral cancer, but it spreads more widely and has different risk factors than most other oral cancers. More Information on Nasopharyngeal Cancer: Head, Neck & Mouth Cancer
The North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition, an association of professionals focused on improving the digestive health of children through research and eduction.
A type of antidiabetic agent used in the treatment of type 2 diabetes. It works by lowering the levels of glucose circulating in the body and may be used alone or in combination with other antidiabetics. More Information on Nateglinide: Diabetes & Endocrine Drugs
The National Academy of Sciences (NAS) is a private, non-profit society chartered by the U.S. Congress. Its scholars conduct research in science and technology for public benefit and advise the federal government in scientific and technical matters.
A nonprofit coalition of national organizations created in 1996 to conduct research, do policy analysis, develop national programs and increase public awareness of family caregiving issues.
A nonprofit advocacy organization of consumers, families, and friends of people with severe mental illnesses. Founded in 1979, it works to achieve equitable services and treatment for Americans with mental illnesses.
A nonprofit organization that promotes public education, research, rehabilitation and support services to assist people with aphasia and their families.
A division of the National Institutes of Health (NIH) and the principal U.S. agency for cancer research and training. It supports and conducts research, collects and disseminates information and is involved in education and awareness initiatives.
A National Institutes of Health organization dedicated to exploring complementary and alternative healing practices in the context of rigorous science.
A program of the National Heart, Lung and Blood Institute, NCEP directs its educational efforts on public awareness of cholesterol as a major risk factor for coronary heart disease (CHD). Its goal is to reduce death and disease resulting from CHD.
A voluntary association of approximately 1,200 institutions, conferences, organizations and individuals that organizes the athletics programs of many U.S. colleges and universities.
A division of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) specializing is providing information about digestive diseases.
A program overseen by the Centers for Disease Control and Prevention (CDC), designed to assess the health and nutritional status of Americans. Started in the 1960s, the survey combines information from interviews and physical exams.
A program of the National Emergency Medicine Association to support NEMAs mission of promoting research and education in the fight against cardiovascular disease.
One of the National Institutes of Health, the NHLBI coordinates national priorities in the research of diseases related to the heart, blood vessels, blood and lungs, as well as sleep disorders. It performs research and funds others through grants.
A division of the United States National Institutes of Health (NIH) that focuses on diabetes and endocrinology, as well as metabolic, digestive, kidney, urologic and hematologic diseases. It conducts and supports research in these areas.
An organization that works to improve mental health through biomedical research on the mind, brain and behavior. It is part of the federal government's National Institutes of Health (NIH).
An organization that promotes a broad scientific effort to understand the nature of aging and to extend the healthy, active years of life. It is part of the federal government's National Institutes of Health (NIH).
A federally funded medical research organization. The goal of the NIH is to acquire knowledge to help prevent, detect, diagnose and treat disease. Cancer research is conducted through the NIH's National Cancer Institute.
The world's largest medical library, it is part of the National Institutes of Health (NIH). The library collects materials and provides information and research services in all areas of biomedicine and health care.
The country's oldest and largest nonprofit organization addressing all aspects of mental health and mental illness. Its 340 affiliates provide advocacy, education, research and services.
A national non-profit organization that serves neurofibromatosis patients. Neurofibromatosis causes tumors along the nerve pathways and leads to developmental abnormalities.
A U.S. Department of Agriculture (USDA) program started in 1946 to provide federally funded low-cost or free nutritious lunches to students in public and nonprofit private schools and residential childcare institutions.
An organization dedicated to improving public health and safety by achieving understanding of sleep and sleep disorders while supporting sleep-related education, research and advocacy.
The NSA is dedicated to professional and public issues related to all aspects of stroke treatment, rehabilitation and prevention. Programs and activities are geared toward professional and patient education, as well as family support.
An independent, consumer-oriented not-for-profit organization founded in 1988 to focus on disease prevention and wellness for women. The NWHRC delivers information on a wide range of women's health issues, including heart-related conditions.
A survey conducted by the U.S. Department of Agriculture (USDA) roughly every 10 years that monitors the nutrient intake of a cross section of U.S. citizens.
Method of contraception that uses periodic abstinence from sexual intercourse during the ovulation period of the menstrual cycle. More Information on Natural Family Planning: Contraception
White blood cells specialized to kill target cells either infected with viruses or host cells that have become cancerous. Known as "natural" killers because they do not need to recognize a specific antigen in order to attack.
"Natural Rubber Products" is more commonly referred to as "Latex" in the medical community. Latex
Also Known As: "Brazilian Rubber Tree Sap"
The milky sap derived from the rubber tree and used in many products, such as rubber gloves, rubber bands, condoms, tubing and Band-Aids. One in every 1,000 people develops a latex allergy. More Information on Latex: Latex Allergy
A feeling of stomach discomfort or queasiness that may be accompanied by an urge to vomit. It can be caused by a number of factors or diseases and may also occur as a side effect of some treatments. More Information on Nausea: Digestive Health Basics
Stomach discomfort or queasiness (nausea) that may be accompanied by the forceful regurgitation of stomach contents (vomiting). These can be caused by a number of factors or diseases and may also occur as a side effect of some treatments. More Information on Nausea & Vomiting: Digestive Health Basics
"Navicular Osteochondrosis" is more commonly referred to as "Kohler Disease" in the medical community. Kohler Disease
Also Known As: "Kohler's Osteochondrosis of the Tarsal Navicular"
A rare bone disorder of the foot in children that may be the result of stress-related compression at a critical time during the period of growth. More Information on Kohler Disease: Arm & Leg Pain
A voluntary association of approximately 1,200 institutions, conferences, organizations and individuals that organizes the athletics programs of many U.S. colleges and universities.
A National Institutes of Health organization dedicated to exploring complementary and alternative healing practices in the context of rigorous science.
A program of the National Heart, Lung and Blood Institute, NCEP directs its educational efforts on public awareness of cholesterol as a major risk factor for coronary heart disease (CHD). Its goal is to reduce death and disease resulting from CHD.
A division of the National Institutes of Health (NIH) and the principal U.S. agency for cancer research and training. It supports and conducts research, collects and disseminates information and is involved in education and awareness initiatives.
"NCL" is more commonly referred to as "Neuronal Ceroid Lipofuscinosis" in the medical community. Neuronal Ceroid Lipofuscinosis
A group of progressive, fatal neurological diseases. Most types begin in early childhood, but one form begins in adulthood. Symptoms are similar, but the age at which they start and the way they progress varies by condition. More Information on Neuronal Ceroid Lipofuscinosis: Pediatric Brain & Nerve
"NCV Study" is more commonly referred to as "Nerve Conduction Velocity" in the medical community. Nerve Conduction Velocity
Also Known As: "Nerve Conduction Study, Nerve Conduction Test"
A test that measures the speed of electrical impulses through a nerve. It assesses nerve function to diagnose causes of muscle problems (e.g., weakness, twitching, paralysis). It is often done along with an electromyography. More Information on Nerve Conduction Velocity: Brain & Nerve Tests
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