Egypt's second faith is Coptic Christianity. Copts are heirs of an ancient Christian rite. Coptic Christianity was the predominant religion in Egypt until the 10th century when a lot of Christians diverted to Islam. Christianity itself was brought in Egypt by St. Mark in the middle of the first century AD.
Other possible causes of swelling behind the knee include abscesses (infections); tumors of the skin, soft tissue, or bones; bleeding; deep venous thrombosis (blood clot in the deep veins of the legs); or deformity of the joint after a fracture of any of the bones of your knee joint.
Injury and Overuse. Injury of any of the leg structures is a leading cause of acute inflammation and swelling. With the leg muscles and tendons, overuse may also cause inflammation. Swelling of the more superficial muscles at the back of the lower leg â gastrocnemius or soleus â is more likely to contribute to visible swelling.