Why do I have swelling that will not go away?

This is a question I often get from clients that I see in my physical therapy practice. In my clinical practice I often see patients with persistent swelling, which we medical people refer to as edema or lymphedema. As a way to avoid confusion for the purposes of this article, I will refer to all of these conditions with the general term “swelling” as a physical therapist trained and certified in lymphedema/edema management there can be a wide ranging variety of causes for swelling, from dietary habits to genetics. To better understand what is happening, it helps to understand the mechanisms that create swelling. Before you stop reading out of fear that this will be a confusing article filled with scientific jargon please read on, I promise to do my best with the use of some simple analogies to explain the how and why of swelling. I often use these analogies with my clients to help them visualize what is going on. Persistent swelling is almost always the result of the accumulation of fluid in the interstitial space. The interstitial space is a fancy word for the space between the individual cells that make up our bodies. Think of the cells as houses on a street, and the streets, alleyways, and yards as the interstitial space surrounding those houses. Just like a house, the cells of our body require supplies like water, electricity, and food to be brought in from the interstitial space outside and garbage and waste need to be taken out. When conditions change this interstitial space can become flooded much like when a river overruns its banks.

What causes swelling?

Fluid retention: The most common cause of swelling is a temporary swelling referred to as fluid retention which is often the result of varying dietary habits or hormonal shifts. These episodes are typically short lived, and the swelling is alleviated as the diet is adjusted or hormone levels shift.

Injury: Another common cause that triggers inflammation and can result in swelling. Anyone who has ever sprained an ankle, “jammed” their finger, or had the misfortune of breaking a bone has experienced the body’s incredibly quick swelling response. Without getting too technical the swelling in the interstitial space is due to an accumulation of large inflammatory molecules and proteins from the injury acting like a sponge, pulling water from the circulatory system. As the body heals the swelling is reduced through the gradual removal of those large molecules and proteins from the interstitial space.

Other medical conditions:

  • Venous Insufficiency

  • Congestive Heart Failure

  • Breast Cancer

  • Primary Lymphedema

Further information on each medical condition will be covered in part II of this blog, coming next week!

Ways to manage Swelling

The standard recommendation in cases of minor sprains and strains is RICE (Rest, Ice, Compression, and Elevation). This is good advice as each of these actions help reduce swelling and pain.

How does RICE actually work?

Rest allows the body to heal the damage and remove those molecules. Consistent Icing not only decreases pain but also slows down the metabolism of the inflammatory process allowing the body time to catch up in removing those large molecules and proteins. Using the sponge analogy, Compression squeezes the interstitial space preventing fluid from being pulled into the sponge. Elevation allows gravity to assist with moving the fluid away from the affected area. We will discuss compression in more detail in Part III of this article, but one common mistake is the idea that with compression “more is better”. Effective compression in almost all cases is gentle like using tubigrip, a compression sleeve, or lightly applied wrap. In cases where the swelling remains, and the body cannot seem to catch up Lymphedema Therapists often get involved.


For further information on other medical conditions that cause swelling make sure to check out part II of this article!


Steve Johnson DPT is a Physical Therapist from the La Crosse area with over twenty years of clinical practice experience and has been Lymphedema Certified Therapist since 2004.



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