Grinding Pain

• If you experience grinding pain when you are walking, consult your doctor. It is grinding pain if you feel the bones in your knee grinding against each other with each step you take. The pain could be a sign of several things such as chondromalacia patella--the softening of the cartilage--or meniscal tear, which is a rip in the cartilage of your knee. Both of these are treatable by doctors but if left untreated can lead to worse injuries.
  
  

Instability

• Instability in the knee, e.g. the knee giving out without warning during routine activity, is a sign that you need to see a doctor. If you combine instability with severe pain, it could be a sign that you have a tendon injury. There are three main types of tendon injuries; they affect the anterior cruciate ligament, posterior cruciate ligament or the medial collateral ligament, better known as ACL, PCL or MCL injuries, respectively. These most likely will require surgery to fix, but they are treatable.
  
  

Infection

• If the knee and the area surrounding it become swollen and hot to the touch, or if the skin becomes red and irritated, it is a sign that you need to seek urgent medical care because you may have a joint infection. Infections can spread rapidly and if left untreated can lead to a score of problems including amputation and even death. An infection can be treated easily with antibiotics and should not be ignored. A infection could mean that you have an underlying issue within your knee, including possibly a fracture, that is causing other symptoms.
  
  

Tips

• If you know the cause of your knee pain is from a bruise or a bump, treat it with an over-the-counter anti-inflammatory and alternate cold and hot compresses to relieve pain and swelling.
  
  As with all medical issues, if you have any questions or concerns about a serious injury or lingering pain, you should contact your medical professional immediately.