Prefix · anatomy · heart
Means "heart": cardiogram, cardiology, cardiovascular, cardiac, cardiomyopathy.
Written by Bryan López, English teacher · Updated
Cardio- comes from the Greek kardia, which means "heart". You will see it mostly in medical vocabulary, always related to the heart and the circulatory system. If you spot cardio- in a word, the heart is part of the story.
Cardio- has a double life. At the gym, "do cardio" means exercise that speeds up the heart and strengthens it. At the hospital, it is the base of the vocabulary used by doctors who care for the heart. Heart disease is the leading cause of death in the world, so this prefix is very useful for understanding health news.
Combines mainly with Greek and Latin roots in medical contexts:
Pronunciation: /ˈkɑːr.di.oʊ/.
cardio-/ˈkɑːr.di.oʊ/
Tap the button to hear how the prefix sounds. Each word in the table has its own audio.
"Cardiogram" (cardio- = heart + Greek "gramma" = written record): any graphic recording of cardiac activity. An ECG or EKG (electrocardiogram) is the specific type that records electrical activity, and is the most common in clinical use. In everyday speech, "cardiogram" and "ECG/EKG" are often used interchangeably.
A trick to remember it
Think of "cardio" class at the gym, which speeds up your heart: cardio- = heart. cardiogram, cardiovascular.
Exercise 1 · Form the word
Exercise 2 · Pick the right one
What does cardiology study?
The prefix cardio- means "heart": cardiogram, cardiology, cardiovascular, cardiac, cardiomyopathy.
The prefix cardio- is pronounced /ˈkɑːr.di.oʊ/. For example, "cardiogram".
"gram" becomes "cardiogram". It is a typical example of the cardio- prefix.
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