Obesity

• When an additional amount of weight is placed on the knees it can cause them to become sore and fatigued. Obesity puts the knees at risk for almost all types of injuries. Even when no pressure is put on the knees from standing upright, additional weight pushes on the tendons, muscles and joints, causing them to hurt even while sitting still.
  
  

Arthritis

• Arthritis is the most common cause of any type of joint pain. Arthritis is inflammation of the joints, which causes a burning and intense ache. It is most commonly brought on by age and genetics.
  
  

Bursitis

• The bursae of the knee is filled with tiny sacs filled with fluid that help cushion the bone and the tendons. Bursitis happens when these tiny sacs become inflamed, usually due to overuse from activities such as constant kneeling or long-distance running. Bursitis is tender, red and swollen, and is associated with intense pain.
  
  

Dislocation of Knee Cap

• Knee dislocation happens when the knee cap shifts from its place, causing friction on the outer tendons. Knee dislocation happens a lot during sporting activities when the knee is twisted wrong; it can also happen from falls. When the knee becomes dislocated it swells and is very tender to the touch.
  
  

Strain/Sprain

• Strains and sprains happen when there is an abrupt move and the knee is twisted to an unfamiliar position. The tendons and muscles around the knee become swollen and inflamed. Strains and sprains heal with time and rest.
  
  

Tendinitis

• The tendons connect the muscles to the bones. They can become inflamed as they age, due to a loss of flexibility. Tendinitis also happens when the knees are overused without proper stretching and movement. Tendinitis shows symptoms of swelling and is accompanied by an intense ache around and behind the knee.