Lymphedema is a chronic condition characterized by the abnormal accumulation of protein-rich fluid, known as lymph, in the tissues, most often in the arms or legs. This swelling occurs because the lymphatic system, which is responsible for draining this fluid, has been damaged or is not functioning correctly. Compression garments serve as a primary tool in the long-term management of this condition, working by applying external pressure to the affected limb. This consistent pressure helps to support the tissues, prevent the reaccumulation of fluid, and assist the natural movement of lymph back toward functional drainage pathways.
Specific Compression Requirements for Lymphedema
Compression garments used for lymphedema management are medical devices engineered to provide a precise level of pressure, measured in millimeters of mercury (mmHg). Unlike standard support socks, these garments must deliver a sustained, strong pressure to be effective in controlling the swelling and preventing the progression of tissue changes. The required pressure level is determined by a specialist based on the severity and stage of the lymphedema.
For mild cases or as a preventative measure, a class of 20–30 mmHg may be sufficient, while moderate to severe lymphedema often requires a firmer class of 30–40 mmHg or even 40–50 mmHg. A fundamental characteristic of these garments is the “pressure gradient,” where the highest pressure is applied at the ankle or wrist, the point furthest from the body’s core. This pressure then gradually decreases as the garment moves up the limb, effectively pushing the lymph fluid upward from the swollen area. This graduated application of force supports the body’s own efforts to return fluid.
Flat Knit Versus Circular Knit Construction
The choice of construction method is often the most significant factor in selecting an appropriate compression garment for lymphedema. Compression socks are generally made using one of two methods: circular knit or flat knit. Circular knit garments are manufactured seamlessly, resulting in a smoother, more elastic fabric that is commonly used for mild edema or venous conditions. They are generally suitable for limbs with a more regular shape.
Conversely, flat knit garments are created by knitting row-by-row and then seaming the fabric together, allowing them to be shaped precisely to the contours of the limb. This method produces a much stiffer material with a higher “wall stability,” which is beneficial for moderate to severe lymphedema. The rigidity of the flat knit fabric is crucial because it resists stretching, preventing the garment from sinking into skin folds or tissue indentations. This robust construction ensures that pressure remains consistent and uniform across irregular limb shapes, providing the necessary containment to control fluid accumulation.
Essential Steps for Proper Sizing and Fitting
For a compression garment to function correctly, the fit must be exact. Off-the-shelf sizing is frequently inadequate for lymphedema patients because swelling can cause the limb to have disproportionate or asymmetrical circumferences. Therefore, professional measurement by a certified lymphedema therapist or trained fitter is highly recommended.
These measurements must be taken when the limb is at its smallest, ideally first thing in the morning before swelling increases, or immediately following a therapy session. The therapist will take multiple circumference and length measurements at specific points on the limb, such as the ankle, calf, and thigh. For individuals with severe swelling or an unusual limb shape, custom-made flat knit garments are often necessary, as they are specifically tailored to the patient’s unique measurements. Obtaining medical-grade compression often requires a prescription or referral from a healthcare provider.
Maintenance and When to Replace Compression Socks
Proper care is necessary to ensure the therapeutic life of medical compression garments. To preserve the elasticity and pressure of the fabric, garments should be washed frequently using a mild detergent and either hand-washed or placed on a gentle machine cycle. They must be air-dried flat and should never be put in a machine dryer, as direct heat will quickly damage the elastic fibers.
Patients should also avoid applying oil-based lotions or moisturizers right before donning the garment, as ingredients in these products can break down the fabric’s elastic components. Compression garments must be replaced regularly, typically every three to six months, to maintain their therapeutic effectiveness in managing lymphedema. If the garment feels noticeably looser, starts to slip, or shows signs of wear such as thinning or fraying, it is an indication that it needs immediate replacement.