Medical Terminology Prefixes and Their Meanings

Number and Quantity Prefixes

• Mono-, Uni- (one):
  • Monodiplopia: Double vision that occurs only in one eye.
  • Unilateral: Confined to one side only.
• Bi-, Di- (two, twice, double):
  • Diplopia: Double vision.
  • Bilateral: Affecting two sides.
• Tri- (three):
  • Trigeminal nerve: The fifth cranial nerve, providing sensory innervation to the face, divided into three main branches.
• Quad-, Quadra-, Tetra- (four):
  • Quadrant: Areas divided for descriptive purposes into quadrants.
  • Tetradactyl: Having four fingers or toes on a hand or foot.
• Multi- (many):
  • Multicellular: Composed of many cells.
• Poly- (too much, many):
  • Polyuria: Excessive excretion of urine.
• Hemi-, Semi- (half or partly):
  • Hemiplegia: Paralysis of one side of the body.
  • Semicomatose: State of drowsiness and inaction, requiring more than ordinary stimulation to evoke a response.

Other Common Prefixes

• Hyper- (excessive, more than normal):
  • Hyperemesis: Excessive vomiting.
  • Hypertension: High blood pressure.
• Hypo- (beneath or below normal):
  • Hypothermia: Core body temperature below the normal range.
  • Hypotension: Low blood pressure.
• Nulli- (none):
  • Nulliparity: Not having given birth to a child.
• Pan- (all):
  • Panarthritis: Inflammation of all parts of a joint.
• Primi- (first):
  • Primigravida: A woman during her first pregnancy.
• Ab- (away from):
  • Abduct: Movement of a limb away from the median plane of the body.
• Ad- (towards):
  • Adduct: Movement of a limb toward the median plane of the body.
• Ante- (before, in front of):
  • Antecubital: In front of the elbow.
• Ambi- (both, both sides or around):
  • Ambidextrous: Able to work equally well with either hand.
• Peri- (around):
  • Periarterial: Surrounding an artery.
• Dia- (through):
  • Diathermy: Therapeutic use of electromagnetic energy to generate heat within a body part.
• Ento- (inside, within):
  • Entocornea: The posterior limiting membrane of the cornea.
• Meta- (beyond):
  • Metacarpal: Beyond the carpals.
• Epi- (above, upon):
  • Epigastrium: The superior central portion of the abdomen.
• Hypo-, Infra-, Sub- (beneath, under):
  • Inframammary fold: Zone on the chest wall below the female breast.
  • Subclavian: Below the clavicle.
• Ecto- (outer):
  • Ectoderm: Outer layer of cells in a developing embryo.
• E-, Ex-, Exo- (out of, outside):
  • Eversion: Turning outward.
• En-, Endo- (inside):
  • Endocarditis: Inflammation of the inner lining of the heart.
• Extra- (outside of, beyond):
  • Extrahepatic: Located outside of or unrelated to the liver.
• Inter- (between):
  • Intercostal: Between the ribs.
• Intra- (within):
  • Intravenous: Within a vein.
• Para- (near, beside):
  • Parathyroid: Adjacent to the thyroid gland.
• Per- (through or by means):
  • Percutaneous: Passage of substances through the skin.
• Re- (back, again):
  • Reduce: Surgical procedure to place back into a preferred position after fracture or dislocation.
• Retro- (behind or backward):
  • Retrosternal: Behind the breastbone.
• Super-, Supra- (above, beyond):
  • Superficial: On or near the surface.
  • Suprarenal: A location above each kidney.
• Syn- (joined, together):
  • Syndactylism: Webbing of the fingers or toes.
• De- (away, take away):
  • Dehydrate: To become free of water.
• Trans- (across):
  • Transection: Cutting across.
• Pre- (before):
  • Predisposition: The potential to develop a disease or condition.
• Post- (after):
  • Postmortem: Occurring after death.
• Macro- (large):
  • Macrocephaly: Abnormally large size of the head.
• Micro- (small):
  • Microdontism: Disproportionately small teeth.
• A-, An- (without):
  • Anoxia: Absence of oxygen.
• In- (not):
  • Inoperable: Unsuitable for surgery.
• Pseudo- (false):
  • Pseudoarthrosis: A new, false joint arising at the site of an ununited fracture.
• Un- (not):
  • Unconscious: Not conscious.
• Anti-, Contra- (against):
  • Antiseptic: Agent capable of preventing the growth of disease-causing microorganisms.
  • Contraindication: A symptom or circumstance that makes treatment unsafe or inappropriate.
• Dys- (difficult, painful):
  • Dysphagia: Difficulty in swallowing.
• Eu- (good or normal):
  • Eupnea: Normal, unimpaired respiration.
• Mal- (bad):
  • Malalignment: Displacement from a normal position.
• Hydro- (water):
  • Hydrocephalus: Accumulation of excessive cerebrospinal fluid within the brain ventricles.
  • Hydrophobia: Fear of water; property of repelling water molecules.
• Ortho- (straight, correct):
  • Orthopedics: Branch of medicine dealing with the correction of locomotor structure disorders.
• Brady- (slow):
  • Bradycardia: A slow heartbeat, with a pulse rate below 60 beats per minute in an adult.
• Tachy- (fast):
  • Tachycardia: Rapid heart rate of over 100 beats per minute.

Color, Condition and Other Prefixes

• Albin/o- (white):
  • Albinism: Inherited partial or total absence of pigment in skin, hair, and eyes.
• Chlor/o- (green):
  • Chloroplast: Small green cell organelle in plants, site of photosynthesis.
• Cyan/o- (blue):
  • Acrocyanosis: Bluish discoloration of the extremities.
• Erythr/o- (red):
  • Erythrocyte: Red blood cell that carries oxygen to tissue.
• Xanth/o- (yellow):
  • Xanthopia: Optic condition causing objects to appear yellow.
• Poli/o- (gray):
  • Poliomyelitis: Inflammatory process involving the gray matter of the spinal cord.
• Crypt/o- (hidden):
  • Cryptorchid: Failure of one or both testes to descend.
• Lipo- (fat):
  • Lipoma: Benign tumor consisting of mature fat cells.