Medical Prefixes that Describe the Position or Direction

The prefix ab- means "away". Example is the word ab/duct/ion. ab- is a prefix that means "away",  duct is is a word root that means "to lead or to carry" and -ion is a suffix that means "action or process". Abduction is a movement in which a limb or structure is pulled away from the body's median plane.

The prefix ad- means "toward". Example is the word ad/duct/ion. ad- means "toward",  duct is a word root that means "to lead or to carry" and -ion is a suffix that means "action or process". Adduction is the motion of pulling something toward the midline of the body or towards the midline of a limb.

The prefix ambi- means "both". Example is the word ambi/phil/ia. ambi- means "both",  phil is a word root that means "attraction" and -ai is a suffix that means "condition". Ambiphilia is an attraction to both men and women.

The prefix ante- or anter(o)- means "anterior or front". Example is the word anter(o)/sept/al. Anter(o)- means "front",  sept is a word root for "septum", -al is a suffix that means to "pertaining to". The term anteroseptal refers to the area in front of a septum, most notably the interventricular septum.

The prefix ventr(o)- or ventr(i)- means "anterior or front". Example is the word ventr(o)/crani/al. Ventr(o)- means "front",  crani is a word root for "cranium or skull", -al is a suffix that means to "pertaining to". A ventrocranial is a term used to refer to the front of the skull.

The prefix dextr(o)- means "right". Example is the word dextr(o)/cardi/a. Dextr(o)- means "right",  cardi is a word root for "heart", -a is a noun ending suffix with no specific meaning. Dextrocardia is a congenital condition characterized by the abnormal position of the heart on the right side of the chest.

The prefix ect(o)- means "out" or "outside". Example is the word ect(o)/derm. Ect(o)- means "outside",  derm is a word root that refers to the "skin". Following the formation of the three primary germ layers, the ectoderm is the outermost layer of cells of an embryo.

The prefix ex(o)- means "out" or "outside". Example is the word ex(o)/therm/ic. Ex(o)- means "outside",  therm is a word root that refers to the "heat", -ic is a suffix that means "pertaining to". In an exothermic process, heat is released into the environment.

The prefix extr(a)-  or extr(o)- means "out" or "outside". Example is the word extra/cellular. Extra- means "outside",  cellular pertains to the "cell". An extracellular term refers to something occurring or found outside a cell.

The prefix end(o)- means "inside". Example is the word end(o)/metr/i/um. End(o)- means "inside",  metr/i is a combining form that refers to the "uterus", -um is a noun ending suffix with no specific meaning. Endometrium is the innermost lining layer of the uterus. 

The prefix intra- or intro- means "inside" or "within". Example is the word intra/muscul/ar. Intra- means "inside",  muscul is a word root that refers to the "muscle", -ar is a suffix that means "pertaining to". The intramuscular refers to the inside of the muscle.

The prefix ep(i)- means "above". Example is the word ep(i)/derm/is. Ep(i)- means "above", derm is a word root that refers to the "skin", -is is noun ending suffix with no specific meaning. A layer of tissue that forms the outermost layer of skin is referred to as the epidermis. 

The prefix supra- means "above". Example is the word supra/ren/al. Supra- means "above", ren is a word root that refers to the "kidney", -al is a suffix that means "pertaining to". The suprarenal glands, also known as the adrenal glands, are small glands on top of the kidneys.

The prefix super- means "above" or "excessive". Example is the word super/ior. Super- means "above", -ior is a suffix that means "pertaining to". Superior refers to being higher or located above.

The prefix inter- means "between". Example is the word inter/atri/al. Inter- means "between", atri is a word root for "atrium of the heart", -al is a suffix that means "pertaining to".  The interatrial septum is the wall between the atria of the heart.

The prefix later(o)- means "lateral" or "side". Example is the word later(o)/crani/al. Later(o)- means "lateral" or "side", crani is a word root for "cranium" or "skull", -al is a suffix that means "pertaining to".  Laterocranial is the term for the side of the cranium.

The prefix mes(o)- means "middle". Example is the word mes(o)/blast. Mes(o)- means "middle", -blast is a suffix that refers to "immature cell".  In an embryo, the mesoblast is the middle layer of undifferentiated cells; it becomes the mesoderm.

The prefix medi(a)- or medi(o)- means "middle". Take the word medi(o)/tars/al. Medi(o)- pertains to "middle", tars is a word root that refers to "ankle", and -al is a suffix term that means "pertaining to". Mediotarsal is in the middle of the tarsal (ankle) region.

The prefix para- means "near", "apart from" or "abnormal" . Example is the word para/thyr/oid. Para- in the term parathyroid means "beside" or "near", thyr is a word root for "thyroid gland", -oid is a suffix that means "resembling". Parathyroid glands are four endocrine glands located near the thyroid gland, which secrete parathyroid hormone.

The prefix juxta- means "near". Example is the word juxta/spin/al. Juxta- means "near", spin is a word root for "spine", -al is a suffix that means "pertaining to". The term juxtaspinal refers to an area near the spine.

The prefix peri- means "around" or "surrounding". Example is the word peri/cost/al. Peri- means "around", cost is a word root for "rib", -al is a suffix that means "pertaining to". Pericostal refers to the area surrounding a rib.

The prefix circum- means "around" or "surrounding". Example is the word circum/gastr/ic. Circum- means "around", gastr is a word root for "stomach", -ic is a suffix that means "pertaining to". Circumgastric refers to the area surrounding a stomach.

The prefix poster(o)- means "back" or "posterior". Example is the word poster(o)/bucc/al. Poster(o)- means "back", bucc is a word root for "cheek", -ic is a suffix that means "pertaining to". Posterobuccal refers to the posterior or back part of the cheek.

The prefix dors(o)- or dors(i)- means "back" or "posterior". Example is the word dors(i)/flex/ion. Dors(i)- means "back", flex is a word root for "bend", -ion is a suffix that refers to "process". Dorsiflexion can be described as the backward bending or contracting of your hands or feet. 

The prefix sinistr(o)- means "left". Example is the word sinistr(o)/ocul/ar. Sinistr(o)- means "left", ocul is a word root for "eye", -ar is a suffix that means "pertaining to". A sinistrocular error occurs when the left eye is favored by habit or for effective vision over the right eye.

The prefix levo- means "left". Example is the word levo/scoli/o/sis. Levo- means "left", scoli/o is a combining form that pertains to "curved", -sis is a suffix that means "condition". The term 'levoscoliosis' refers to a type of scoliosis where the spine curves on the left side.

The prefix sub- means "below" or "under". Example is the word sub/cutane/ous. Sub- means "below", cutane is a word root that pertains to the "skin", -ous is a suffix that means "pertaining to". Subcutaneous refers to the fatty layer that lies under the skin.

The prefix infra- means "below" or "under". Example is the word infra/clavicul/ar. Infra- means "below", clavicul is a word root that pertains to the "clavicle" or "collar bone", -ar is a suffix that means "pertaining to". The infraclavicular fossa is located below the clavicle.

The prefix tele- or telo- means "distant". Example is the word tele/canthus. Tele- means "distant", canthus refers to the corner of the eye where the upper and lower lids meet. Telecanthus means that the distance between the medial canthi of the eyes increased, whereas the interpupillary distance remains normal.

The prefix trans- means "through". Example is the word trans/derm/al. Trans- means "through", derm is a word root for "skin", -al is a suffix that means "pertaining to". Transdermal is a form of medication administration in which ingredients are absorbed through the skin into the bloodstream. 

The prefix dia- means "through". Example is the word dia/lysis. Dia- means "through", -lysis is a suffix that means "separating" or "dissolution". When the kidneys stop working, dialysis removes and separates wastes and excess fluids from the blood through a machine to be cleaned.

The prefix per- means "through". Example is the word per/cutane/ous. Per- means "through", cutane is a word root for "skin", -ous is a suffix that means "pertaining to". Percutaneous refers to a form of administration or procedure that passes through the skin, either as an injection or as a topical injection.