This article contains a list of commonly used medical abbreviations and acronyms that start with the letter N and may be encountered in medicine and radiology (please keep the main list and any sublists in alphabetic order).

A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z - misc

• N

  • asparagine (single letter amino acid code)

  • neutron number

  • newton (SI derived unit of force)

  • nitrogen

• n: nano (SI prefix for 10^-9)

• N0, N1, N2, N3: nodal stages (TNM)

• N₂: nitrogen gas (dinitrogen)

• N₂O: nitrous oxide

• NA

  • Nomina Anatomica

  • norepinephrine

  • nucleic acid

• Na: sodium (Latin: natrium)

• NAA: N-acetylaspartic acid

• NAC

  • N-acetylcysteine

  • nipple-areolar complex

• NACT: neoadjuvant chemotherapy

• NAD

  • no abnormality detected

  • nil abnormality detected

• NAI: non-accidental injury

• NAFLD: non-alcoholic fatty liver disease

• NAPH: non-aneurysmal perimesencephalic subarachnoid hemorrhage

• NASCET: North American symptomatic carotid endarterectomy trial

• NASH: non-alcoholic steatohepatitis

• NB

  • neuroblastoma

  • newborn

  • nota bene: take special note of "..." (L: note well)

• Nb: niobium

• NBCA: N-butyl-2 cyanoacrylate (embolization glue)

• NBF: Neville Barnes forceps

• NBM: nil by mouth

• NBTE: non-bacterial thrombotic endocarditis

• NC: non-contrast

• NCAP: neck chest abdomen pelvis

• NCL: neuronal ceroid lipofuscinosis

• NCP: nursing care plan

• NCS: nerve conduction studies

• NCSE: non-convulsive status epilepticus

• Nd: neodymium

• NDT: nasoduodenal tube

• Ne: neon

• NEDA: no evidence of disease activity (usually multiple sclerosis)

• NEC

  • necrotizing enterocolitis

  • not elsewhere classified

• NERD: non-erosive reflux disease

• NESB: non-English speaking background

• NET: neuroendocrine tumor

• NEX: number of excitations

• NF1: neurofibromatosis type 1

• NF2: neurofibromatosis type 2

• NFA

  • no fixed abode

  • no fixed address

• NFPA: non-functioning pituitary adenoma

• NFR: not for resuscitation

• NFT: neurofibrillary tangle

• NG: new growth (old-fashioned euphemism for cancer)

• ng: nanogram/nanogramme

• NGS: next-generation sequencing

• NGT: nasogastric tube

• NH: nursing home

• NHL: non-Hodgkin lymphoma

• NHNA: naevoid hyperkeratosis of the nipple and the areola

• NHR: nursing home resident

• NHS: National Health Service (UK)

• Ni: nickel

• NICE: National Institute for Health and Care Excellence (UK)

• NICU

  • neonatal intensive care unit

  • neurological (neurosurgical/neurosciences) intensive care unit

• NIDDM: non-insulin-dependent diabetes mellitus

• NIH: National Institutes of Health (US)

• NIPPV

  • nasal intermittent positive pressure ventilation

  • non-invasive positive pressure ventilation

• NIS: sodium-iodide symporter

• NIV: non invasive ventilation

• NJT: nasojejunal tube

• NKA: no known allergies

• NKDA: no known drug allergies

• NLD: nasolacrimal duct

• NLP: natural language processing

• NMDA: N-methyl-D-aspartic acid

• NMIBC: non-muscle invasive bladder cancer

• NMO: neuromyelitis optica

• NMR: nuclear magnetic resonance

• NMSC: non-melanoma skin cancer

• NMV: net magnetization vector

• NNH: number needed to harm

• NNT: number needed to treat

• NO: nitric oxide

• NOAC

  • non-vitamin K oral anticoagulant agent

  • novel oral anticoagulant agent

• NOE: naso-orbitoethmoid

• NOF

  • neck of femur

  • non-ossifying fibroma

• NOH: neck of humerus

• NOS: not otherwise specified

• Norad: norepinephrine

• NP

  • nasopharyngeal

  • necrotizing pancreatitis

• Np: neptunium

• NPC: nasopharyngeal carcinoma

• NPH: normal pressure hydrocephalus

• NPL: no perception of light

• NPO: nil per os (Latin: nothing by mouth)

• NPRS: numeric pain rating scale

• NPPV: non-invasive positive pressure ventilation

• NPV: negative predictive value

• NPWT: negative pressure wound therapy

• NRFHR: non-reassuring fetal heart rate

• NRI: nerve root injection

• NRS: numeric rating scale

• NSAID: non-steroidal anti-inflammatory drug

• NSCLC: non-small cell lung cancer

• NSE: neuron specific enolase

• NSF: nephrogenic systemic fibrosis

• NSGCT: non-seminomatous germ cell tumor

• NSIP: non-specific interstitial pneumonia

• NSR: normal sinus rhythm

• NSTEMI: non-ST elevation myocardial infarct

• NSTI: necrotizing soft tissue infection

• NT: nuchal translucency

• NTM: non-tuberculous Mycobacterium

• NTM-PD: non-tuberculous mycobacterial pulmonary disease

• NUCOG: neuropsychiatry unit cognitive assessment tool 

• nullips: nullipara

• N&V: nausea and vomiting

• N/V: nausea, vomiting

• NVC: neurovascular conflict/compression

• NVD

  • nausea, vomiting, diarrhea

  • normal vaginal delivery

• NVvR: Nederlandse Vereniging voor Radiologie (Dutch Radiological Association)

• NWB: non-weight bearing

• Nx: nodes cannot be assessed (TNM)

• NYD: not yet determined

• NYHA: New York Heart Association

• NZ: New Zealand