The most common medical word parts — prefixes, roots and suffixes — explained in plain English with an example each, so you can decode unfamiliar terms.
Last updated: September 9, 2026
Most medical words are built from Greek and Latin word parts: a prefix (the beginning), a root (the core meaning, usually a body part), and a suffix (the ending, often a condition or a procedure). Learn the highest-frequency parts once and you can decode thousands of terms — for example tachy- (fast) plus cardi/o (heart) gives tachycardia, a fast heart rate.
| Term | Definition |
|---|---|
| tachy- | Fast or rapid. Example: tachycardia, a fast heart rate. |
| brady- | Slow. Example: bradycardia, a slow heart rate. |
| hyper- | Above normal or excessive. Example: hypertension, high blood pressure. |
| hypo- | Below normal or deficient. Example: hypoglycemia, low blood sugar. |
| dys- | Difficult, painful, or abnormal. Example: dysphagia, difficulty swallowing. |
| cardi/o | Heart. Example: cardiology, the study of the heart. |
| hepat/o | Liver. Example: hepatitis, inflammation of the liver. |
| nephr/o | Kidney. Example: nephrology, the study of the kidneys. |
| gastr/o | Stomach. Example: gastritis, inflammation of the stomach. |
| dermat/o | Skin. Example: dermatology, the study of the skin. |
| neur/o | Nerve or nervous system. Example: neurology, the study of the nervous system. |
| oste/o | Bone. Example: osteoporosis, porous and weakened bone. |
| hemat/o | Blood. Example: hematology, the study of blood. |
| pneumon/o | Lung or air. Example: pneumonia, infection of the lungs. |
| leuk/o | White. Example: leukocyte, a white blood cell. |
| -itis | Inflammation. Example: arthritis, inflammation of a joint. |
| -ectomy | Surgical removal. Example: appendectomy, removal of the appendix. |
| -otomy | Surgical incision (cutting into). Example: tracheotomy, an incision into the trachea. |
| -ostomy | Surgical creation of an opening. Example: colostomy, an opening made into the colon. |
| -ology | The study of. Example: cardiology, the study of the heart. |
| -pathy | Disease. Example: neuropathy, nerve disease. |
| -emia | Blood condition. Example: anemia, a low red blood cell count. |
| -algia | Pain. Example: neuralgia, nerve pain. |
| -megaly | Enlargement. Example: cardiomegaly, an enlarged heart. |
| -osis | Abnormal condition. Example: cyanosis, a bluish discoloration of the skin. |
| -uria | Urine condition. Example: hematuria, blood in the urine. |
Quizzes, flashcards and spaced repetition — free to get started.
Start learning free →Prefixes, roots and suffixes are the building blocks of medical language. Once you recognize the common parts, you can break an unfamiliar term into pieces and work out its meaning instead of memorizing every word on its own.
Yes. This vocabulary is core to US health programs — nursing school and NCLEX prep, pre-med, and medical assistant training. MediLearn lets you drill these terms with quizzes and flashcards using spaced repetition.
Below normal or deficient. Example: hypoglycemia, low blood sugar.
Lung or air. Example: pneumonia, infection of the lungs.
Disease. Example: neuropathy, nerve disease.