Popping and cracking sounds from the joint may be a normal phenomenon, especially in younger age group. If they are associated with pain, with or without swelling, then there may be a pathological reason inside the joint that cause these sounds. They can be caused by soft tissue inside the joint called plica, rubbing of the cartilages against each other called the meniscus or due to a meniscal tear. Imaging techniques like x-rays and MRI can help rule out such diseases.