Medicine The current criteria for definition of FUO (fever of un- known origin) is that the fever lasting for more than___ weeks. A 7 days B 15 days C 21 days D 28 days 💡 Explanation The current criteria for definition of FUO (fever of un- known origin) is that the fever lasting for more than___ weeks. ✓ Correct Answer: C. 21 days