Are combining vowels in medical terminology always o?

Combining vowels are not always 'o' in medical terminology. While 'o' is a common combining vowel, other combining vowels also exist. Here are a few examples:

1. '-a' is used in words like 'myalgia' (muscle pain) and 'odynophagia' (painful swallowing).

2. '-e' is used in words like 'nephrectomy' (surgical removal of a kidney) and 'appendicitis' (inflammation of the appendix).

3. '-i' is used in words like 'tonsillitis' (inflammation of the tonsils) and 'peritonitis' (inflammation of the peritoneum).

4. '-u' is used in words like 'pyuria' (pus in the urine) and 'urticaria' (hives).

However, 'o' is indeed the most commonly used combining vowel. It appears in words such as 'phlebotomy' (drawing blood), 'osteoporosis' (brittle bones), and 'dermatology' (the study of skin).