Signs and symptoms of water on the knee typically include:
- Swelling. The flesh around your kneecap may puff up noticeably. This swelling is most apparent when you compare the affected knee to the normal one.
- Stiffness. When your knee joint contains excess fluid, you may not be able to bend or straighten your leg completely.
- Pain. Depending on the cause of the fluid buildup, the knee may be very painful — to the point that it's impossible to bear weight on it.
When to see a doctor
Seek prompt medical attention if:
- Self-care measures or prescribed medications don't relieve the pain and swelling
- One knee becomes red and feels warm to the touch as compared to your other knee