Medical Terminology Basics: 305 Useful Terms to Know!

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An Introduction: Medical Terminology Basics

Table of Contents

It's all Greek (or Latin) to Me!

You ever go to the doctors’ office and suddenly find the physician speaking a some language that sounds somewhat familiar – but not quite intelligible? Perhaps you love watching medical dramas and there’s always a point each episode where the physicians are talking about hematocrit this or hemostasis that. It can be very intimidating and exciting to hear the language of medicine.

Well this introduction to medical terminology basics will hopefully give you some more confidence insight into what’s being said! We are going to break down some of the most common terms encountered in medicine on this lecture!

History of Medical Terminology

Most medical terminology comes from Greek and Latin, however some words come from different and more modern languages. 

Greek Terms: These words tend to describe clinical terminology. It’s easy to build terms in Greek. Gastritis is a great example. Gastro- for stomach and -itis for swelling/inflammation. 

Latin Terms
: Anatomy is described pretty much exclusively in Latin. 

For the purposes of this lecture we won’t go into what words are Greek vs Latin and just keep it simple

Beginnings, Middles, and Ends!

A medical term is composed of a few parts that fit together like Legos. These are our Prefixes, Roots, Suffixes. Or another way to put it beginnings, middles, and ends! Medical terminology basics starts with these three components. 

The Root: Right in the middle, this part tells you what you’re talking about. It’s the most important part of the word. 

The Prefix: Before the root. This part helps you orient yourself. You get the reasons, circumstances, and conditions of word here.

The Suffix: AKA The End. This tends to be the most confusing part of the word for many people. It tends to convey information about procedures, conditions, states of being, or diseases.

It’s important to know the difference between terms in each part, because if you tell a patient they may need a treatment for a colostomy and you mean to say colitis…. they will not be happy if they look it up!

100 Medical Root Words

Root Word Meaning Example Literal Not Real Meaning
1 Acr--/o Extremities Acromegaly Enlarged Extremities
2 Amb-/i Both Sides Ambidextrous Both Hands
3 Adren-/o Adrenal Adrenalectomy Adrenal Removal
4 Anter--/o Front Anterior
5 Aud/i-/o Hear Audiogram Hear Record
6 Aut--/o Self Autophagy Self Eating
7 Axill--/o Armpit Axillary Nodes
8 Arth-/o Joint Arthrocentesis Joint Aspiration
9 Bio- Life Biology Study of Life
10 Brachi-/o Arm Brachioplexus Arm Braid
11 Bucc-/o Cheek Buccal gland
12 Caput-/o Head Caput succedaneum Head Substitute
13 Cardi-/o Heart Pericardium Around Heart
14 Carcin-/o Cancer Carcinogen
15 Carp-/o Wrist Carpal Tunnel Syndrome
16 Cervic-/o Neck Cervical Stenosis Neck Narrowing
17 Cheil-/o Lip Cheilosis
18 Chil-/o Lip
19 Chir-/o Lip
20 Chol-/e-/o Gall
21 Cholecyst-/o Gallbladder Cholecytecomy Gallbladder Removal
22 Choledoch-/o Common Bile Duct Choledocolithiasis Common Bile Duct Stone
23 Cili-/o Eyelash Ciliary
24 Cor-/o Pupil Cornea
25 Cost-/o Rib Costophrenic Angle
26 Crani-/o Skull Craniotomy
27 Cubit-/o Elbow Cubital Tunnel
28 Cyt-/o Cell Cytokine Cell Movement
29 Dactyl-/o Fingers Dactylitis Finger Inflammation
30 Derm-/a-/o Skin Dermatitis Skin Inflammation
31 Dermat/a-/o Skin
32 Duoden/o Duodenum Duodenal Ulcer
33 Ech-/o Sound Echocardiogram Sound Heart Picture
34 Estr-/o Female Estrogen Female Producing
35 Faci-/o Face Facial Nerve
36 Gastr/i-/o Stomach Gastritis Stomach Inflammation
37 Gingiv-/o Gums Gingivitis Gum Inflammation
38 Glauc-/o Gray Glaucoma Gray Swelling
39 Gloss-/o Tongue Glossopharyngeal Nerve
40 Gluc-/o Sugar Glucose Sugar Full
41 Gnath-/o Jaws Micrognathia Small Jaws
42 Hepat-/o Liver Hepatitis Liver Inflammation
43 Hist-/o Tissues Histology Study of Tissues
44 Inguin-/o Groin Inguinal Canal
45 Intestin-/o Intestines
46 Irid-/o Iris
47 Labi-/o Lips
48 Lapar-/o Abdomen Laparotomy Abdomen Opening
49 Later-/o Side Dorsolateral Back and Side
50 Lingu-/o Tongue Lingual Nerve
51 Lip-/o Fats Lipoma Fat Mass
52 Lymph-/o Lymph Lymphoma Lymph Mass
53 Mamm-/a-/o Breast Mammogram Breast Record
54 Mast-/o Breast Mastectomy Breast Removal
55 Melan-/o Black Melanocyte Black Cell
56 My-/o Muscle Myoclonus Muscle Confused
57 Myel-/o Bone Marrow Myeloblast Bone Marrow Immature Cell
58 Nas-/o Nose Nasopharyngeal
59 Necr-/o Death Necrosis Death State
60 Nephr-/o Kidney Nephrology
61 Neur-/o Nerve Neuroblastoma
62 Odont-/o Teeth Odontophobia Teeth Fear
63 Occipit-/o Back of Head Occipital Bone
64 Ocul-/o Eye Oculoscope Eye Instrument
65 Ophthalm-/o Eyes Opthalmoscope Eye Instrument
66 Or-/o Mouth Oropharynx
67 Oss-/e-/o Bone Marrow Intraosseus Injection
68 Ot-/o Ear Otoscope Ear Instrument
69 Palat-/o Roof of Mouth Palatoplasty Roof of Mouth Repair
70 Pancreat-/o Pancreas Pancreatitis Pancreas Inflammation
71 Path-/o Disease Pathology Study of Diseases
72 Pelv/i-/o Pelvis Pelvis
73 Pharmac-/o Drugs Pharmacokinetics Drug Motion
74 Phleb-/o Vein Phlebotomy Vein Cutting
75 Phren-/o Diaphragm Costophrenic Cartilage
76 Pil-/o Hair Piloerection
77 Pulmon-/o Lungs Pulmonologist
78 Pod-/o Foot Podiatry Foot Healing
79 Psych-/o Mind Psychology Study of the Mind
80 Rect-/o Rectum
81 Rhin-/o Nose Rhinoplasty Nose Repair
82 Sacr-/o Sacrum Sacroilliac
83 Sept-/o Infection Septic Shock
84 Sial-/o Saliva Sialadenitis
85 Somat-/o Body Somatoform Disorder
86 Splen-/o Spleen Splenectomy Spleen Removal
87 Steth-/o Chest Sthethoscope Chest Instrument
88 Tal-/o Ankle Talofibular
89 Tars-/o Foot Metatarsals
90 Thorac-/o Chest Thoracentesis Chest Aspiration
91 Thyr-/o Thyroid Thyroid
92 Toxic-/o Poison Thyrotoxicosis Thyroid Toxic
93 Trachel-/o Neck Tracheotomy Neck Opening
94 Trich-/o Hair Trichotillomania Hair Delusion
95 Ur-/e-/o Urine Urease Urine Cleave
96 Uter-/o Uterus In Utero
97 Ventr-/o Front Ventral Side
98 Vesic-/o Bladder
99 Viscer-/o Viscera (Aka internal organs) Viscerosomatic Viscera Body
100 Xer-/o Dry Xeromycteria Dry Nostril

52 Prefixes

Number Prefix Meaning Comments / Examples
1 A- Not/Lacking Anoxic
2 Algo- Pain Algogenic
3 An- Without Angiogenesis
4 Ab- Away Abductors -Think "Away"
5 Ad- Towards Adductors - Think "ADDing"
6 Brady- Slow Bradycardia
7 Brachy- Short Brachydactyly
8 Cata- Lower Cataracts
9 Com- Together Composite
10 Contra- Opposite Contralateral
11 Dis- Apart Distal
12 Dys- Bad Dysgenesis
13 Epi- Above Epiphysis
14 Encephalo- Brain Encephalitis
15 Extra- Beyond Extra Occular
16 Extro- Outside Extroverted
17 Hemato- Blood Hematocrit
18 Hemi- Half Hemicolon
19 Hyper- Excessive Hypercalcemia
20 Inter Between Interstitial
21 Intra- Within Intracapsular
22 Intro- Into Introductory
23 Macro- Large Macrocytic
24 Mal- Bad Malaise
25 Mes- Middle Mesolimbic
26 Meso- Middle Mesocortical
27 Meta- Change Metastasis
28 Micro- Small Microcytic
29 Neo- New Neoplasm
30 Neuro- Nerve Neurotoxic
31 Oligo- Small / Scarce Oliguria
32 Onco- Tumor Oncogenic
33 Pan- All / Throughout Pancytopenia
34 Para- Beyond / After Parasite
35 Per- Through Perception
36 Peri- Around Peripheral
37 Poly- Many Polyuria
38 Post- After Postoperative
39 Presby- Old Age Presbyopia
40 Pseudo- Fake Pseudoscience
41 Quadri- Four Quadriplegic
42 Re- Again Reoccurance
43 Retro- Behind Retroperitoneal
44 Semi- Half See Hemi
45 Sub- Under Subsection
46 Super- Above Superior
47 Sym- Together Sympathetic
48 Syn- With / Joint Synchondrosis
49 Tachy- Fast Tachycardia
50 Trans- Through Transection
51 Tri- Three Triscuspid
52 Endo- Within Endocarditis

Hey! Did you notice that some repeat words on the root words and pre-fix list? Thank the Greeks! Words like -Cardio- can be used in many creative ways. 


So I can say ‘Myocardium’ and you would know I’m talking about Heart Muscle or if I say ‘Cardiogenic’ it means from the heart. Pretty neat right?

51 Suffixes

Number Suffix Meaning Comments / Examples
1 -ac / -al / -ic Pertaining to Cardiac "Cardio- + -ac"
2 -algia Pain Myalgia
3 -arche Beginning Menarch
4 -ase Enzyme Protease
5 -cele Protrusion Hydrocele
6 -centesis Fluid Withdrawal Pericardiocentesis
7 -cidal Kill / Destroy Fungicidal
8 -clasis Break Arthroclasis
9 -constriction Narrowing Venoconstriction
10 -ctye Cell Pneumocyte
11 -desis Surgical Fusion Fasciodesis
12 -dilation Expansion Venodilation
13 -dynia Pain Mastodynia
14 -ectasis Stretch Atelectasis
15 -ectomy Removal Craniectomy
16 -edema Swelling / Inflammation Angioedema
17 -ema Condition Erythema
18 -emia Related to blood Anemia
19 -emesis Vomit Hematemesis
20 -euysm Expanding Aneurysm
21 -form Resembling Fusiform
22 -genesis Origin Angiogenesis
23 -genic Produced By Vasogenic
24 -globin Protein Hemoglobin
25 -gram Record Mammogram
26 -graph Recording Instrument Elecrtrocardiograph (EKG)
27 -graphy Process of Recording Chromotography
28 -ia Condition Phobia
29 -ism Process Allochroism
30 -itis Inflammation Gastritis
31 -lysis Cut / Separate Hemolysis
32 -malacia Softening Osteomalacia
33 -mania Obsession Hypermania
34 -megaly Enlargement Hepatomegaly
35 -mortem Death Postmortem
36 -oma Mass / Tumor Lipoma
37 -one Hormone Testosterone
38 -opsy Display Of Autopsy
39 -ostomy Artificial Surgical Opening Colonostomy
40 -otomy Incision / Cutting Tracheotomy
41 -paresis Weakness Hemiparesis
42 -penia Deficiency Osteopenia
43 -phagia Devour / Eat Dysphagia
44 -phasia Speech Dysphasia
45 -pnea Breathing Apnea
46 -rrhea Flow Rhinorrhea
47 -scope Instrument to Examine Stethoscope
48 -scopy Examination Fluoroscopy
49 -somnia Sleep Insomnia
50 -stasis Stop Hemostasis
51 -uria Urine Polyuria

102 Useful Medical Terms

Number Term Meaning
1 Acute Sudden onset
2 Admit the act or process of accepting someone into a hospital, clinic, or other treatment facility as an inpatient
3 Adverse Effects An unexpected medical problem that occurs with a treatment drug/therapy
4 Albumin Protein made by the liver that prevents fluid from leaking out of the bloodstream
5 AMA Against Medical Advice
6 Angina Marked chest pain
7 Anhedonia Inability to feel pleasure
8 Anoxic Without oxygen
9 Apnea Temporary cessation of breathing
10 Arterial Relating to the arteries
11 Asymptomatic Presenting without any symptoms despite having a disease
12 Autonomic Part of the nervous system that supplies the internal organs
13 Benign Not cancerous
14 Biopsy Sample of tissue to be examined
15 Bradycardia Heart Rate <60
16 Carcinogen Substance that can cause cancer
17 Caudad Toward the feet
18 Cephalad Toward the head
19 Chronic Long-lasting
20 Coma A deep state of prolonged unconsciousness in which a person cannot be awakened
21 Concussion A head injury that temporarily affects brain functioning.
22 Creatinine A waste product by muscles
23 CT Scan a useful imaging modality that produces tomographic images of a body, allowing the user to see inside the body without cutting into it
24 Cytokine Substances secreted during an immune response
25 Demarcated Boundary
26 Diabetes Mellitus A disease that leads to impaired insulin regulation
27 Distal Away from center of the body
28 DNR Do Not Rescusitate
29 Dorsal Upper side
30 Dyspnea Difficulty breathing
31 Echocardiogram Ultrasound-based imaging to create an outline of the heart
32 Edema Swelling
33 Embolism Obstruction of an artery
34 EMR Electronic Medical Records
35 Endocarditis Inflammation within the cardiac walls
36 Erythema Reddening of the skin due to dilatation of capillaries
37 Etiology Origins of a disease
38 Exacerbation Worsening of a disease
39 Fascia Flat band of tissue below the skin that covers underlying tissues and separates different layers of tissue
40 GERD Gastroesophageal reflux disease (GERD) is a long-term condition where acid from the stomach comes up into the esophagus
41 Guarding An involuntary reaction to protect an area of pain
42 Hematocrit Value that indicates how much of a person's blood is made up of red blood cells
43 Hemoglobin Molecule that carries oxygen
44 Hyperglycemia High levels of glucose
45 Hyperlipidemia High levels of lipids
46 Hyperreflexia Overactive reflexes
47 Hypertension High blood pressure
48 Hyporeflexia Underactive reflexes
49 Hypotension Low blood pressure
50 Hypoxic Low levels of oxygen
51 Idiopathic Denoting an unknown cause
52 Infectious Easily transmitted between hosts
53 Inpatient Someone admitted into the hospital
54 Lesion Damage or abnormal change in the tissue of an organism, usually caused by disease or trauma
55 Leukemia Cancer of the body's blood-forming tissues, including the bone marrow and the lymphatic system
56 Ligament Fibrous connective tissue
57 Lymphoma Cancer of the lymphatic system
58 Malaise a general feeling of discomfort, illness, or uneasiness whose exact cause is difficult to identify
59 Malignant Cancerous with ability to spread to other parts of the body
60 Medicaid A USA health insurance program for those with limited income
61 Medicare The USA's health insurance program for people age 65 or older or with a disability
62 Metabolic Syndrome The name for a group of risk factors that raises your risk for heart disease and other health problems
63 MRI Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body.
64 Multifactorial Denoting multiple causes
65 Myalgia Muscle pain
66 Myocardial Infarction An event where cardiac tissue is deprived of oxygen and dies
67 Neoplasm Abnormal tissue growth
68 Neutrophils The most common type of white blood cell
69 Noncompliant Referring to a patient who does not take their medications or follow medical recommendations
70 Noninvasive A procedure that doesn't require opening the body
71 Order Written directions provided by a prescribing practitioner for a specific medication to be administered to an individual
72 Orthopnea Difficulty breathing while lying down
73 Outpatient Someone receiving medical treatment outside of the hospital. i.e. a clinic
74 Parasympathic The part of the involuntary nervous system that serves to slow the heart rate, increase intestinal and glandular activity, and relax the sphincter muscles.
75 Parenteral Administered or occurring elsewhere in the body than the mouth and alimentary canal
76 Pleurisy Inflammation of the pleura that seperates the lungs from the chest wall
77 Pneumonia Infection that occurs in the air sacs of the lungs
78 Polypharmacy Usage of multiple medications concurrently
79 Proximal Close to center of the body
80 Pulmonary Embolism A blood clot that blocks one or more pulmonary arteries
81 Referred pain Pain occuring at a site other that the affected area
82 Remission Temporary or permanent disapperance of the signs and symptoms of cancer or other disease
83 Rhinorrhea Runny Nose
84 Seizure An electrical disturbance that results in abnormal activity of the brain
85 Sepsis Massive inflammation as a result of infection leading to a life-threatening condition
86 Shock Sudden drop in blood pressure resulting in the person not being able to get enough blood or oxygen to their organs
87 Side Effects A documented effect that can occur with a treatment drug/therapy
88 Sinusitis Inflammation of the sinuses
89 Stroke Manifestation of a part of the brain lacking oxygen and blood flow leading to cell death
90 Subacute Rather recent onset or somewhat rapid change.
91 Subcutaneous Below the skin
92 Sympathetic A part of the nervous system that serves to accelerate the heart rate, constrict blood vessels, and raise blood pressure
93 Syncope Temporary loss of consciousness
94 Tachycardia Heart Rate >100
95 Tender Pain to touch
96 Troponin Protein that can indicate cardiac damage
97 Ulcer Open sore or erosion
98 Valgus excessive outward angulation of the distal segment of a bone or joint
99 Varus excessive inward angulation of the distal segment of a bone or joint
100 Venous Relating to the veins
101 Ventral Underside
102 Virulent Indicating a rapid, severe, and destructive course for a viral infection

What Next?

Look for opportunities to learn more words by hearing them as they are used, reading them online in context and studying them using sources like medical terminology books

You’ll find that the best way to learn though is to use them yourself in real life. 

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