Some common conditions that cause knee and leg pain are bursitis, osteoarthritis and tendonitis, according to WebMD and Mayo Clinic. However, there are a multitude of conditions that cause knee aches and leg pain. Some are related, while others are separate conditions that are caused by different types of injuries.
Knee pain, which is very common and affects up to half of all athletes, is often caused by damage to ligaments or cartilage tearing, notes WebMD. Bone chips are another cause of pain in the knee. They occur when an injury to the knee breaks off small pieces of bone or cartilage, which become stuck in the knee. Sometimes, the kneecap can become partially dislocated, or tissue called plica may become irritated with overuse, causing knee pain.
Leg pain is normally caused by overuse or damage to the muscles, ligaments and tendons, according to Mayo Clinic. In some cases, leg pain is caused by a problem in the lower spine, blood clots or varicose veins. Some other common causes of leg pain include deep vein thrombosis, gout, a hamstring injury, ACL injury and fibromyalgia. Leg pain is also caused by peripheral neuropathy, growth plate fractures and juvenile rheumatoid arthritis. In total, there are over 40 possible causes for leg pain listed by the Mayo Clinic.