Swelling of Legs

Post-Polio Health, Volume 27, Number 4, Fall 2011
Ask Dr. Maynard
Frederick M. Maynard, MD

Question: I had polio in 1940. With treatment and exercise I was able to live a “normal” life and taught school for many years. At age 50, I started having new weakness. I am now 79 and my legs have shown greater weakness. I wear a full brace on my left leg and a short brace on my right leg. Lately I have been falling even with my walker. My left leg is very swollen but medical tests do not show anything. Could the late effects of polio be causing the swelling?

Answer: There are many reasons why leg swelling can occur. They all involve fluid retention, and usually the mechanistic cause is inadequate “return flow” of blood carrying fluid out of the leg and back to the heart. If you have had slowly worsening weakness now for many years and at age 79 require a left long leg brace, most likely you have swelling in that leg from inadequate muscle contraction pumping blood back out of the leg when you are upright. This is especially likely to be the explanation if the problem has developed gradually along with slowly increasing post-polio leg weakness and if it is worse later in the day than in the morning (after the leg has been elevated overnight in bed which drains out fluid).

Other common causes for leg swelling are open sores on the foot/leg which can result in lymphedema (excessive fluid production in soft tissues around the sore) and kidney or heart problems that lead to excessive salt and water retention throughout the body, especially in the legs when you are up. In the latter case, there should be swelling in both legs, even if there is more in the weaker left leg where there is less muscle action to pump blood out. Often in older people there is more than one contributing factor to leg swelling.

If swelling appears rather suddenly in one leg only, especially if that leg also becomes painful and red, then you should see a doctor as soon as possible to test for a blood clot in a leg vein. Venous blood clots block the vein from draining blood out of the leg which results in swelling.

The mainstays of management for the symptom of leg swelling, especially when other direct causes are not found, include restricting salt intake, leg elevation as much as possible, and wearing support stockings or using leg wraps. It is important to control leg swelling because it will otherwise gradually worsen and sooner or later lead to additional problems (like open sores/ ulcers, heaviness of the leg that makes it harder to get around, poor fitting of shoes and braces and blood clots, among others).