Signs and symptoms typically include:

  • Swelling. The skin around your kneecap can puff up noticeably, especially when you compare the affected knee to the normal one.
  • Stiffness. When your knee joint contains excess fluid, you might not be able to bend or straighten your leg completely.
  • Pain. Depending on the cause of the fluid buildup, the knee might be very painful — to the point that it's difficult or impossible to bear weight on it.

When to see a doctor

See your doctor if:

  • Self-care measures or prescribed medications don't relieve the pain and swelling
  • One knee becomes red and feels warm to the touch compared to your other knee
May 21, 2015