What is the word part that is affixed to the beginning of a word?

The term that refers to a word part affixed to the beginning of a word is indeed the prefix. Prefixes are crucial in medical terminology because they modify the meaning of the root word to indicate various conditions, locations, times, or the number of instances. For instance, the prefix "hyper-" denotes "excessive" or "above normal," as seen in the term "hypertension," which means elevated blood pressure.

Roots form the base of the word and carry its primary meaning, while suffixes are attached to the end of a word to alter its meaning or function, such as in "itis," which indicates inflammation. Combining vowels, like "o" or "i," serve to connect prefixes and suffixes to roots, making pronunciation easier but do not function as standalone parts of the word. Understanding these components is vital for interpreting and constructing medical terms accurately.