Summarize the following:
If your knees feel like they need to be cracked often, and especially if you have associated pain, you should have them looked at by a doctor. Your doctor should be able to identify the problem and will give you options for treatment.  While some knee popping is perfectly normal, a constant need to pop your knee could signal a problem with your cartilage being worn down, a tear in your meniscus, or developing arthritis.  In many cases, treatment options will include medication, physical therapy, and, if the problem is severe, surgery. In a lot of cases, cracking in the knee occurs when the knee bones are not sitting correctly because there is excessive inflammation between them. If you can reduce this inflammation, then cracking will feel less necessary.  You can take an over-the-counter anti-inflammatory, such as ibuprofen. Talk to your doctor if you think a prescription anti-inflammatory would be more effective for your condition. While it may be tempting to stop moving a knee that feels like it needs to be cracked all the time, it is important to keep it moving. Low-impact exercises that will be good for your knees include:  Swimming. Bicycling. Water aerobics. Elliptical. that are hard on the knees. While some exercises are great for keeping the knees healthy and flexible, there are other exercises that can be particularly bad for knees that are already compromised. Avoid activities that create a strong impact on the knees, particularly activities that include running. If you want to continue running, at least try to give your knees time to recover between sessions. For instance, alternate your running days with days when you do a low-impact exercise like cycling.

Summary:
Consult with a doctor. Take anti-inflammatory medication. Do low-impact knee exercises. Minimize activities