Online Medical Dictionary
Letter N
- Na
- Chemical symbol for sodium.
- Narcolepsy
- A neurological sleep disorder marked by the recurrent, uncontrollable compulsion to sleep during daytime and a disturbed sleep patterns at night. Narcolepsy dyssomnia is not associated with mental illness.
- Nasal Polyp
- Benign, polypoidal growths originating from the mucous membranes lining the nasal passage (nose) or paranasal sinuses. Nasal polyps may develop as a reaction to allergens or other inflammatory stimuli.
- Nasal Prosthesis
- An artificial replacement for a partially or fully absent nose.
- Nasal Septum
- The structures dividing the left and right airways and nostrils of the nose.
- Nasal Septum Deviation
- Displacement of the nasal septum, the structures dividing the airways of the nose, usually caused by injury or trauma, or congenitally. The nose may have been compressed during childbirth, or the deviation may occur as the result of a congenital condition, such as Marfan syndrome, which impedes the necessary tissue from developing.
- Nasogastric
- Regarding the passage that descends from the nose to the stomach.
- Nearsightedness
- See Myopia.
- Necropsy
- A postmortem examination; autopsy.
- Necrosis
- Live cell or tissue death as a result of a toxic, infectious or traumatic trigger that halts blood and oxygen flow to the cells. Necrosis may occur due to cancer, injury or poison emitted by some spider or snake species.
- Neo- (prefix)
- Prefix defining new.
- Neonatal
- Pertaining to the first period of a newborn's life, usually defined as the primary four weeks after the infant is born.
- Neonatal Hyperbilirubinemia
- Neonatal jaundice. Elevated levels of bilirubin in the blood of the newborn causing yellow pigmentation of the skin and sclera (whites of the eyes).
- Neonatal Jaundice
- See Neonatal Hyperbilirubinemia.
- Neonatologist
- A pediatrician specialized in newborn care.
- Neophobia
- An abnormal fear of anything new.
- Neoplasia
- Abnormal cell growth, resulting in the development of neoplasm.
- Neoplasm
- An abnormal amassing of tissue developed out of an abnormal proliferation of cells. Neoplasms may be present on the body in the form of a lump or tumour. Neoplasm can be benign, pre-cancerous or malignant.
- Nephrectomy
- The surgical procedure performed to remove a diseased or defective kidney, or a healthy kidney destined for transplantation.
- Nephritis
- Acute or chronic inflammation of the kidney, induced by a variety of different kidney diseases.
- Nephro-
- Prefix defining a relationship to the kidneys.
- Nephropathy
- Disease of the kidney.
- Neuralgia
- Pain in the nerves, either pertaining to central neuralgia (pain due to damage or injury of the nerves of the central nervous system) or peripheral neuralgia (pain experienced due to injury or damage affecting nerves elsewhere in the body).
- Neurological
- Regarding the nervous system or the body's composite nerves.
- Neurologist
- A physician specialized in the diagnosis and treatment of disorders pertaining to the nervous system.
- Neurology
- A medical specialty focused on the diagnosis and treatment of any disease or disorder of the central, peripheral and autonomic nervous systems.
- Neuroma
- A tumour developed from nerve cells.
- Neuromuscular
- Regarding or affecting both the nervous system and the muscles.
- Neuron
- A nerve cell capable of sending and receiving electrical and chemical signals, composing the core of the body's nervous system.
- Neurone
- Alternative spelling of neuron.
- Neuro-oncologist
- A physician specialized in the diagnosis and treatment of brain tumour and other tumours that may develop in the nervous system.
- Neuropathologist
- A physician specialized in the diagnosis and treatment of diseases of the central nervous system (the brain and spinal chord).
- Neuropathy
- Any disease or disorder affecting the peripheral nervous system; the nerves responsible for transmitting signals between the limbs of the body and the central nervous system.
- Neuroradiology
- A radiology sub-field, specializing in the diagnosis and characterization of disorders and conditions affecting the central nervous system and the peripheral nervous system, usually utilizing the technologies of magnetic resonance imaging (MRI) and computed tomography (CT) scans.
- Neuroscience
- The interdisciplinary, scientific study of the cellular, molecular and functional capabilities and components of the nervous systems of the body. Neuroscience necessitates a collaboration with other sciences, such as physics, mathematics, engineering, psychology and computer science.
- Neurosurgery
- A medical specialty focused on the diagnosis, treatment, prevention of any disorder affecting the nervous systems.
- Norovirus
- The RNA virus responsible for the vast majority of non-bacterial gastric flu and stomach flu, though not related to the influenza virus.
- Nuclear Medicine
- The branch of medicine and medical imaging focused on the use of radionuclides, the process of radioactive decay and administration of formed radiopharmaceuticals in gaining diagnosis and treating disease.
- Nyctalopia
- A condition causing impaired vision in dim light, commonly as a result of retinitis pigmentosa or a Vitamin A deficiency.
- Nyctophobia
- An abnormal fear of the dark.
