Fluid on the Knee

Q:  My doctor tells me I have fluid on my knee but won't explain this condition. My feet, ankles and lower legs often swell up for days, making walking almost impossible. It often feels as if someone is hitting the inside of my knee with a hammer. My knee makes cracking/popping sounds; it also gives way.

My doctor has prescribed Zoloft 50 mg, but it seems the same. I'm 83 years old and did not injure myself. Where, how and why did this fluid come, and why won't it go away? I've been sick since January. Should I soak my feet? Avoid certain foods? I have cut down on my intake of liquids to avoid swelling but nothing seems to work. Please explain this fluid to me. Thank you!

A:  It sounds as if you have two problems going on: 1) a bad knee and 2) generalized swelling of your lower legs and feet.

Let's talk about your knee first.

The knee is a complicated joint that bears a lot of weight and takes a great deal of abuse over the years from walking, bending, and going up and down stairs. It has several ligaments and tendons that can get torn and inflamed and cause popping, locking, grating, giving-way, and swelling of the knee.

An injury from several years ago (which you don't even remember) may just now have degenerated to the point where you're having problems. The swelling in your knee will probably not be affected as much by your fluid intake as by your activity. By the way, Zoloft is a medicine for depression, not for arthritis.

The generalized swelling of your feet and ankles can be due to a variety of conditions, some more serious like heart failure in which your heart doesn't pump the blood as well, or kidney failure where your kidneys can't excrete the fluid from your body too well. Other reasons for swelling may be varicose veins or fluid retention from too much salt in your diet.

Keeping your feet elevated when you're sitting down is a good idea. Some people also have to wear special elastic stockings (similar to support hose) to keep the swelling down. From your letter I can't tell what the reason for your swelling is so it is not possible to give specific advice. Salty foods probably will increase the swelling. I doubt that soaking your feet will help, but discuss this with your doctor so he or she can decide what is best for you.

"Dear Doctor" is a compilation of patient questions answered by doctors from the Medical College of Wisconsin.