Varicose veins are a manifestation of chronic venous disease, where the valves inside the leg veins become damaged. This damage causes blood to flow backward and pool, increasing pressure and leading to the enlarged, twisted appearance of varicose veins. Compression therapy is the primary non-invasive treatment to manage symptoms and slow disease progression. By applying graduated pressure, compression garments assist the veins in pushing pooled blood back toward the heart, counteracting gravity and venous reflux.
Defining Compression Levels (mmHg)
The pressure delivered by compression garments is standardized and measured in millimeters of mercury (mmHg). Compression stockings provide “graduated” pressure, meaning the pressure is strongest at the ankle and decreases progressively up the leg. This gradient profile encourages upward blood flow, which is crucial for therapeutic effectiveness.
Compression levels are categorized into distinct numerical ranges. The mildest category is 8-15 mmHg, considered light support and widely available over-the-counter (OTC). The next level, 15-20 mmHg, offers medium support, also commonly found OTC, and addresses minor symptoms.
Once compression strength moves to the 20-30 mmHg range, it is classified as a medical-grade garment (Medical Class I). This level provides firm compression and is typically recommended by a physician. Higher-level medical compression includes 30-40 mmHg (Medical Class II) and 40-50 mmHg (Medical Class III), which deliver extra-firm support for severe venous conditions. These stronger garments require a prescription or medical supervision.
Clinical Indications for Specific Compression Strengths
The severity of venous symptoms correlates directly with the level of compression required. Mild compression (8-15 mmHg) is appropriate for preventive purposes and minor discomfort. This level helps alleviate mild aching or tired legs, reduces minor swelling, and provides support during long periods of sitting or standing. It is often recommended during pregnancy to help prevent the formation of varicose veins.
The 15-20 mmHg range provides a more therapeutic effect for individuals with mild varicose veins or noticeable leg heaviness. This medium support level is frequently used post-sclerotherapy to prevent treated veins from reappearing and manages mild edema. It is suitable for people experiencing initial signs of venous insufficiency.
The 20-30 mmHg range is the standard for managing diagnosed moderate varicose veins and controlling moderate edema. This level is also commonly prescribed for patients with Chronic Venous Insufficiency (CVI) and those recovering after vein procedures to promote healing. Since this range provides firm medical-grade pressure, a healthcare provider’s recommendation is advised before starting therapy.
Compression garments in the 30-40 mmHg and higher ranges are reserved for treating severe venous disorders. The 30-40 mmHg level is indicated for pronounced varicose veins with severe edema, active venous ulcers, and managing post-thrombotic syndrome following a deep vein thrombosis (DVT). The highest levels, 40-50 mmHg, are used for severe lymphedema or complex post-thrombotic cases and must be used under strict medical guidance.
Proper Measurement and Garment Selection
The effectiveness of compression therapy relies on the garment delivering the correct graduated pressure, making accurate measurement essential. Measurements should be taken early in the morning, before gravitational forces cause significant leg swelling. Using a flexible measuring tape directly on the bare skin provides the most precise results.
The most critical measurement point is the circumference of the ankle at its narrowest point, just above the ankle bone, as this is where maximum compression pressure is applied. Additional key circumference measurements include the widest part of the calf and, for thigh-high garments, the widest part of the thigh. Length measurements are also necessary to ensure the garment does not bunch or constrict improperly.
Having measurements taken by a certified fitter or medical professional is often recommended to match dimensions to the manufacturer’s sizing chart. While standard sizing works for many, those with unique leg shapes or significant swelling may require custom-made garments. Selecting the appropriate style, such as knee-high for isolated issues or thigh-high for more extensive disease, should be done in consultation with a physician.