Osteoarthritis: This is the main cause in older people. The cartilage that prevents friction between the bones in the knee wears down, causing pain and swelling.
Obesity: As you gain weight, your knees have to support it. This puts excessive pressure on the knee joints and causes pain over time.
Injuries: Injuries to the ligaments or meniscus in the knee during sports or falls can cause severe pain.
Arthritis: Rheumatoid arthritis and gout (increased uric acid) are diseases that cause knee pain.
Muscle weakness: If the muscles around the knee (e.g., the thigh muscles) are not strong, the knee joints will take on extra weight and experience pain.
Wrong lifestyle: Sitting in a chair for a long time, the habit of getting up from the floor, and climbing stairs excessively put pressure on the knees.
