Call for emergency medical help. If you suspect you're having a heart attack, don't hesitate. Immediately call 911 or your local emergency number. If you don't have access to emergency medical services, have someone drive you to the nearest hospital.
The most common causes of knee weakness are osteoarthritis, sprain or strain, and chronic knee pain. Other possible causes, such as injury to the knee, are more rare. Osteoarthritis 22. Sprain or strain 17. Chronic knee pain 15. Knee ligament or meniscus tear 8. Fracture of the leg 4. Bursitis 2.
Swelling of the knee can be caused by injuries to the joint as well as many different medical conditions. Depending upon the cause, knee swelling may be painful or may not produce any other symptoms. In some cases, you may notice tenderness, warmth, difficulties with moving your knee joint, muscle weakness, or bleeding or bruising. Injuries to your knee, including sprains (damage to the stabilizing ligaments of the joint), can lead to diffuse swelling of the knee area.