Starvard.
Starvard University · Medical Terminology 101
You will read and understand the language of medicine, the first step into almost any healthcare job. This course teaches the word parts behind the long words, system by system, using MedlinePlus and the National Library of Medicine, until a chart note reads like a sentence you simply understand.
Hello, my name is Finn, and I'm going to help you understand this course.
Here it is, explained like you are 10:
Medical words look long and scary, but most of them are built from small parts, like bricks. Cardi means heart, itis means swelling and inflammation, and ology means the study of something. Put the bricks together and cardiology just means the study of the heart. This course teaches you the bricks, one system of the body at a time, until long words slow down and make sense.
MedlinePlus, the consumer health service of the National Library of Medicine, offers a tutorial called Understanding Medical Words that teaches exactly this method: put together parts of medical words, using word roots, prefixes, and suffixes, with appendices listing word parts and common abbreviations. This course follows that same method and checks its terms against MedlinePlus plain language pages.
One promise and one boundary frame the whole course. The promise: by the end you will break an unfamiliar term into parts, name the body system it belongs to, and read a simple medical record in plain words. The boundary: this course is education for understanding medical words, not medical advice. Your own health questions always belong with your own care team.
The whole course in brief
What you will be able to do after this course
The ten lessons
Lesson 1
Every long medical word is a small sentence wearing a lab coat. Most terms are built from three kinds of parts. A word root carries the core meaning, usually a body part: cardi means heart, gastr means stomach, neur means nerve, derm means skin. A prefix goes before the root and adjusts the meaning, often with a number, place, or direction: hyper means above normal, hypo means below normal, brady means slow, tachy means fast. A suffix goes after the root and tells you what is happening: itis means inflammation, ectomy means surgical removal, scope means an instrument for looking, and scopy means the act of looking.
A fourth helper joins the parts. A combining vowel, usually the letter o, links a root to another root or to a suffix that begins with a consonant, which is why you see cardi/o, oste/o for bone, and arthr/o for joint. The vowel drops out when the suffix begins with a vowel, so arthr plus itis becomes arthritis, inflammation of a joint, not arthroitis.
To decode a word, read it in a special order: suffix first, then prefix, then the root or roots in the middle. Take gastroenteritis. The suffix itis says inflammation. The roots gastr and enter say stomach and intestine. Read it back to front and you get inflammation of the stomach and intestine.
Build a small working set first and build it well: cardi, hemo and hemat for blood, neuro, gastro, derm, osteo, arthr, hepat for liver, nephr for kidney, pulmon for lung, and cyt for cell. Pair them with the suffixes itis, ectomy, tomy for cutting, pathy for disease, logy for study, and algia for pain. Twenty or so honest parts unlock hundreds of real words, and every lesson after this one adds parts system by system.
Lesson 2
Healthcare loves abbreviations because charts are busy, and hates some of them because handwriting is human. A short form that is perfectly clear to its writer can be dangerously unclear to its reader. The Joint Commission, which accredits hospitals, keeps an official Do Not Use list of abbreviations, symbols, and dose writings that accredited organizations must not use in orders and medication related documentation.
The most famous entries show why. Writing U for unit can be misread as the number 0, the number 4, or cc, so the safe habit is to write the word unit in full. IU for International Unit can be misread as IV or as the number 10, so write International Unit. The daily abbreviations Q.D. and QD, and the every other day forms Q.O.D. and QOD, are mistaken for each other, so write daily and every other day in plain words. MS can mean two different medicines, morphine sulfate or magnesium sulfate, and MSO4 and MgSO4 are confused for one another, so those drug names are written out in full as well.
Numbers carry their own two rules on the list. A trailing zero, writing 1.0 mg, invites a missed decimal point and a dose read as 10 mg, so write 1 mg. A missing leading zero, writing .5 mg, invites the same missed point and a dose read as 5 mg, so write 0.5 mg. Notice the pattern: every banned form fails in the same way, by looking like something else at a tired glance.
Many other abbreviations are ordinary and fine in context, such as BP for blood pressure or HR for heart rate, but facilities keep their own approved lists, and your employer's list is the one that governs your charting. When you read an abbreviation you do not know, look it up or ask rather than guessing.
Lesson 3
Before the systems, learn the map. The body is described from a standard reference position called anatomical position: standing upright, facing forward, arms at the sides with palms facing forward. Every directional term assumes that pose, even when the patient is lying down, so left and right never depend on where you happen to stand.
Pairs of opposites do most of the work. Anterior means toward the front, and posterior means toward the back; ventral and dorsal are near synonyms you will meet in records. Superior means above, toward the head, and inferior means below, toward the feet. Medial means toward the midline of the body, and lateral means away from the midline, toward the side. Proximal means closer to the trunk or the point where a limb attaches, and distal means farther away, so the elbow is proximal to the wrist, and the fingers are distal to it.
Depth and region words finish the basic kit. Superficial means near the surface, deep means farther inside. The body is divided into cavities that protect organs, mainly the dorsal cavity holding the brain and spinal cord, and the ventral cavity holding the chest and abdominal organs. You will also meet planes, the flat slices used in imaging: sagittal divides left from right, frontal divides front from back, and transverse divides top from bottom.
These words sound dry until they carry real information. Anterior chest pain, a posterior wound, a distal fracture: each phrase tells a clinician exactly where to look without a single wasted word. Practice by describing your own body as you read: your nose is anterior and medial, your ears are lateral, your knees are inferior to your hips.
Lesson 4
The musculoskeletal system is the body's frame and engine together: bones for support and protection, joints where bones meet, and muscles that pull on the bones to move you. Its word roots are some of the friendliest in medicine. Osteo means bone, arthr means joint, myo means muscle, chondr means cartilage, and ten and tendin mean tendon.
Watch the parts assemble real chart words. Arthritis is arthr plus itis, inflammation of a joint. Osteoarthritis adds osteo, naming a condition of bone and joint together. Osteoporosis builds on porosis, a porous condition, and describes bone that has become less dense. An arthroscope is the instrument for looking inside a joint, and arthroscopy is the procedure of looking. A myopathy is a disease of muscle, and the word is honest about it: myo plus pathy, nothing hidden.
Fracture language is plain once you see it. A fracture is a break, described by where it is, using the directional terms, and by its pattern, with words such as closed, meaning the skin is intact, and open, meaning the bone has broken the skin. Procedures on this system use the surgical suffixes: ectomy for removal, tomy for cutting into, plasty for surgical repair, and centesis for puncturing to withdraw fluid, as in arthrocentesis, puncturing a joint to draw fluid.
MedlinePlus describes the bones, joints, and muscles in everyday language alongside the formal terms, which makes this system a good place to practice translating both ways. Say the plain version first: pain in the joint. Then the term: arthralgia, arthr plus algia.
Lesson 5
Two systems share this lesson because they share a job: moving oxygen in and carbon dioxide out. The cardiovascular system is the heart and blood vessels. Cardi means heart, angi and vas mean vessel, hemo and hemat mean blood, and phleb means vein, while arterio names an artery. The respiratory system is the airway and lungs: pulmon and pneum mean lung or air, bronch names the branching airways, trache names the windpipe, and laryng names the voice box.
Heart words decode quickly. Cardiology is the study of the heart. Cardiomyopathy is a disease of the heart muscle: cardi, myo, pathy. Bradycardia is a slow heart state, tachycardia a fast one, and the suffix cardia tells you the word is about heart action or condition. Electrocardiogram stacks three ideas: electro, electrical; cardi, heart; gram, a record. It is a record of the heart's electrical activity, exactly as advertised.
Breathing words follow the same recipe. Bronchitis is inflammation of the bronchi. Pneumonia names a lung condition, and a pneumothorax is air in the chest cavity. Apnea is a plus pnea: no breathing, a pause in breathing; dyspnea is difficult breathing, and tachypnea is fast breathing. The suffix pnea, breathing, quietly powers a whole family of sleep and lung terms, and the prefixes a, dys, and tachy tell you which member of the family you have met.
Blood words round out the pair. Anemia is an plus emia, a blood condition of lacking, used for a shortage of red blood cells or hemoglobin. Leukemia joins leuk, white, with emia: a blood condition named for white blood cells. A hematologist studies blood, and a phlebotomist is the person who cuts into a vein, phleb plus tomy, to draw blood for tests.
Lesson 6
The digestive system is a long tube with helpful neighbors, and its vocabulary follows the food. Gastro means stomach, enter means intestine, col means colon, hepat means liver, cholecyst points to the gallbladder and bile, esophag names the food pipe, and dent and or name teeth and mouth. The suffixes you already own turn those roots into the words on real charts and clinic doors.
Start at the clinic door: gastroenterology, the study of the stomach and intestines, names a whole specialty. Gastroenteritis is inflammation of stomach and intestine, the chart word behind many miserable nights. Gastritis is the stomach alone, inflamed. Hepatitis is liver inflammation, and its lettered types are labeled with plain alphabet letters after the root word. A gastroscopy looks inside the stomach with a scope, and a colonoscopy does the same for the colon.
Surgical words in this system reward careful suffix reading. A gastrectomy removes some or all of the stomach. An appendectomy removes the appendix. A cholecystectomy removes the gallbladder: cholecyst plus ectomy, a word that is long only until you split it. Contrast those with tomy words, an incision, and stomy words, which name a surgically created opening, as in colostomy. Ectomy, tomy, and stomy differ by a letter or two and by everything that matters, which is why spelling in this field deserves respect.
Symptom words finish the lesson. Dysphagia is difficult swallowing: dys plus phagia, eating or swallowing. Emesis is vomiting, and hematemesis is vomiting blood, the hemo root doing grim, useful work. Diarrhea carries the suffix rrhea, flow or discharge, which you will meet again in other systems.
Lesson 7
The nervous system is the body's wiring and command center: the brain, the spinal cord, and the nerves that carry signals out and back. Neuro means nerve, encephal means brain, myel can mean spinal cord or bone marrow depending on context, cerebr names the largest part of the brain, and psych names the mind. The senses join this lesson because eyes and ears are the nervous system's scouts: ophthalm and ocul mean eye, ot means ear, and audi means hearing.
Brain and nerve words build cleanly. Encephalitis is inflammation of the brain. Neuropathy is a disease of nerves, and neuralgia is nerve pain: neur plus algia. Neurology studies the nervous system, and a neurologist is its physician. An electroencephalogram records the brain's electrical activity: electro, encephal, gram, the same gram you met on the heart's record in the last lesson. Word parts you learn once keep paying rent in every new system.
The senses bring two favorite procedures. An ophthalmoscope is the instrument for looking into the eye, and otoscopy is looking into the ear. Optic means pertaining to vision or the eye, and an audiogram is a record of hearing. Watch for look alike roots as this system multiplies your vocabulary: myel for cord, myo for muscle, and myring for eardrum differ by a few letters and by whole organs.
Pain and sensation words widen the kit. Anesthesia is an plus esthesia: without sensation, the state that makes surgery possible. A related word, analgesia, is without pain while sensation otherwise remains, a distinction the suffixes algia and esthesia let you see at a glance.
Lesson 8
The endocrine system speaks in hormones, chemical messengers released by glands into the blood. Its vocabulary names glands and their messages: thyroid names the thyroid gland, adren names the adrenal glands, pancreat names the pancreas, and the suffixes crine, to secrete, sits inside the system's own name. Hormone words often behave differently, built from gland names and the hyper and hypo prefixes you learned in Lesson 1, which makes this system a prefix playground.
Hyperthyroidism is too much thyroid activity, and hypothyroidism is too little; the whole diagnosis turns on one prefix, which is why Lesson 1 made you learn the pair early. Diabetes terms center on the pancreas and on insulin, the hormone that manages blood sugar, and glyc names sugar, as in hyperglycemia, too much sugar in the blood, and hypoglycemia, too little. Endocrinology is the study specialty, and an endocrinologist is who patients see when glands misbehave.
The reproductive systems bring their own roots. Gynecology is the study and care branch named from gynec, woman, and obstetrics cares for pregnancy and birth, with nat meaning birth inside words such as prenatal, before birth, postnatal, after birth, and neonatal, new birth, the newborn period. Hyster names the uterus, oophor names an ovary, and orchid names a testis. A hysterectomy, removal of the uterus, is one of the most commonly met ectomy words in real records.
These two systems also teach humility about usage. Terms for bodies are used differently across specialties and settings, and records reflect the patient's own anatomy and history, which may include surgeries that changed it. Read what the record actually says rather than what a typical record would say.
Lesson 9
Now put the parts to work on the real thing. A medical record tells a patient's story in a standard order, and each section has a job. Identifying information and the chief complaint say who the patient is and, in the patient's own words, why they came. The history of present illness expands that story: when it started, where it is, what it feels like, and what makes it better or worse. Past medical history, medications, allergies, and family and social history follow, each in its own labeled place.
The review of systems asks, system by system, about symptoms, and the physical examination records what the clinician found, often organized head to toe with the directional vocabulary of Lesson 3. Vital signs appear as numbers with familiar abbreviations: BP for blood pressure, HR for heart rate, and temperature, respiratory rate, and oxygen saturation beside them. Assessment is the clinician's thinking, the diagnoses in term form, and the plan states what happens next: tests, treatments, referrals, and instructions. The old SOAP pattern, subjective, objective, assessment, plan, still shapes many notes.
Try a sentence at full speed. The patient reports anterior chest pain, with dyspnea, worse on exertion. Restated plainly: pain at the front of the chest, with difficult breathing, worse when active. The terms were not decoration. Anterior located the pain, dyspnea named the breathing trouble in one word, and the whole sentence fits on one line of a chart.
Two closing cautions belong in every record reader's pocket. First, records contain errors and copy forward habits, so if a term contradicts the rest of the note, notice it and ask. Second, a record is a person's private information, protected by law and by basic respect. Read only records you have a role based reason to read, and share nothing outside that role. And the course boundary applies to records most of all: this course is education for understanding medical words, not medical advice, for you or for anyone whose chart you will ever hold.
Lesson 10
Here is your final challenge, in three rounds. Round one, decode: split each word and read it back to front. Cardiology: logy, study; cardi, heart; the study of the heart. Osteoarthritis: itis, inflammation; arthr, joint; osteo, bone; inflammation involving bone and joint. Gastroenteritis: inflammation of the stomach and intestine. Bradycardia: a slow heart condition. Nephrectomy: ectomy, removal; nephr, kidney; surgical removal of a kidney. If those five felt friendly, the method has taken root.
Round two, build: given the meaning, assemble the word. Inflammation of the liver: hepat plus itis, hepatitis. An instrument for looking inside a joint: arthr plus scope, arthroscope. Pain in a nerve: neur plus algia, neuralgia. Removal of the gallbladder: cholecyst plus ectomy, cholecystectomy. Too much sugar in the blood: hyper plus glyc plus emia, hyperglycemia.
Round three, stay safe: choose the safe writing. A dose written as 1.0 mg gets rewritten as 1 mg, with no trailing zero. A dose of .5 mg becomes 0.5 mg, with its leading zero restored. U for unit becomes the word unit, and MS becomes the full drug name, morphine sulfate or magnesium sulfate, spelled out. QD becomes the word daily. Each fix follows The Joint Commission Do Not Use list, and each one removes a way for a tired reader to be misled.
Score yourself kindly and honestly. Every word you split correctly is a word you never have to memorize, because you can rebuild it on sight. Keep the habit that made this work: suffix first, then prefix, then roots, one system at a time. You now hold the starter vocabulary of healthcare: its roots, its rules, its dangers, and its maps.
Sources
This course is built from the free health information of the National Library of Medicine and the patient safety standards of The Joint Commission. The word building method and the plain language checks trace to these sources.
Graduation
You learned to read medical words from their parts: suffix first, then prefix, then roots, with the combining vowel as your bridge. You met the vocabulary of the musculoskeletal, cardiovascular, respiratory, digestive, nervous, endocrine, and reproductive systems, learned which abbreviations The Joint Commission says never to use, and read a medical record as the story it is. Keep splitting words instead of memorizing them, remember that this course is education about words and not medical advice, and the language of medicine is open to you from here.
Keep learning
This course is part of Starvard University, striving for greatness.
A note on accuracy: Much of what you read at Starvard was created with help from AI agents, working alongside people. We check what we can, but we cannot guarantee that everything here is true, current, or complete. If something really matters, your health, your money, a grade, a job, please verify it with a trusted source before you rely on it.