How do Compression Garments Work?

Compression Garment


How Compression Garments Work 

Compression garments work by providing external gradient compression to a limb or limbs with a variety of different materials, knitting styles, and compression levels. Their common goal is to maintain swelling in a limb affected by lymphedema. Without these vital garments, the limb will continue to swell, causing pain, fibrosis, open wounds, infection, hospitalization, and possible death.  This is why it is so important to be educated on the different compression garments and how to select the correct one. Selecting the correct garment with these unique (removed “s”) qualities will lead to better patient outcomes and reduce wasted time and money for the patient, hospitals, and insurers.

To understand how compression garments work, you must first understand how they are made. If you are a clinician or a patient with lymphedema or any other swelling disorder, it is very important that you understand the differences between circular knit and flat knit.

How Compression Garments Are Made

Circular knit is made with a machine that knits the fabric in a continuous circle (tube); the weight is “light” and the fabric is thin.

  • Tube shaped
  • Thin
  • A tendency to curl down the limb
  • Pinch (especially in the creases; ankle, behind the knee) causing pain
  • A long stretch, lower containment


Flat knit is made with a machine that knits the fabric in sheets (flat).  Flat knit is thick and made with two rows of needles that are on a 90-degree angle opposite of each other (if this is hard to picture,  think about how your grandmother made a blanket or sweater with two needle-sticks).

  • Fit to the patient
  • Thick
  • Lays flat on the limb
  • Less likely to pinch. Will lay flat over the creases
  • Short stretch, higher containment


Circular Knit vs. Flat Knit

It is a common mistake to be prescribed circular knit because these garments come in ready-to-wear sizes, can be easily obtained, and are cheap. However, whoever invented the phrase “You get what you pay for” was probably speaking specifically about circular knit or ready-to-wear compression garments.

Circular knit is intended for mild edema. For example, if a patient has mild lymphedema (stage 0), circular knit might work for a short period of time but swelling could occur causing pinching at the joints (ankle, wrist, behind the knee) due to the lack of proper structure and containment. This can lead to increased swelling, fibrosis, pitting edema, and possibly cellulitis in the affected limb.

Flat knit compression garments are short-stretch with better containment without pinching. This allows them to be more comfortable and easier to get on. Flat-knit compression garments are custom-made with the intention to fit the limb like a second skin, so they need to be measured by a certified fitter. For example, a custom flat-knit knee-high compression garment requires fourteen measurements while circular-knit only requires three.

Pain is never a normal thing if a patient is wearing the correct compression garment. Always remember, pain and swelling indicate that the wrong compression garment was prescribed.  The correct compression garment will be easier to apply, comfortable, and will supply great containment.


Ready-to-wear, circular-knit compression garments are recommended the most because of the low cost associated with them. A typical ready-to-wear, circular-knit compression garment costs around $50 at a local pharmacy, while a custom, flat-knit compression garment can cost on average $400-$500 per pair. Luckily, custom compression garments are covered by most private insurances, the Veterans Administration, and most state Medicaid plans but not by Medicare. A pair of custom-made knee highs will last an average patient a minimum of 6 months of regular wear and tear.  At $500 a pair for custom, that averages out to $2.77 a day to maintain (removed “your”) swelling. This will help keep limb(s) from swelling to a point where more therapy is required, which would cost much more than $500.

Lymphedema is a chronic disease with no known cure.  However, with proper lymphedema therapy and the correct compression garment, healthy limbs can be maintained.

To summarize, if you are a patient with lymphedema or a clinician trying to assist your patient in a correctly fitting compression garment, flat-knit compression garments will give the patient a much greater chance of being successful in managing their swelling independently.


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Disclaimer: For educational purposes only. This not a substitute for professional care. Do not use this information for diagnosing or treating a health problem or a disease. If you have or suspect you may have a health problem, you should consult your physician. All medical products require a physician’s prescription.