Introduction: Arthritic pain and impairment are all too prevalent with osteoarthritis (OA), the most common form of the illness. Numeric scoring systems can be used to assess knee osteoarthritis (OA) patients' levels of pain. Objective: This study aimed to evaluate the possible factors that increase pain and functional impairment in knee OA leading to increased VAS and WOMAC score. Patients and Methods: On 58 osteoarthritis patients, at Zagazig University Hospitals' Rheumatology and Rehabilitation Department, we conducted this cross-sectional trial. An extensive physical examination, a set of lab tests, and a series of X-rays were all performed on each patient. We utilized the WOMAC index from the Western Ontario and McMasters Universities as well as Visual Analogue Scale (VAS "0-10 cm") to assess functions and pain. For determining the severity, we utilized grading scale of Kellgren and Lawrence. Results: BMI, deformity, ESR, radiological grading are indicators of functional impairment and pain index among cases who had knee osteoarthritis. Conclusion: Presence of knee deformities and advanced X-ray grading were associated with higher pain score and more functional impairment, so we should prevent their progression. BMI is a main risk factor for higher pain scores and functional impairments.