Deep vein thrombosis (DVT) occurs when a blood clot forms in a deep vein, usually in the lower leg or thigh. These clots can block blood flow, causing symptoms like pain, swelling, and warmth in the affected limb. Compression stockings (CS) are specialized elastic garments that apply gentle pressure to the leg to improve circulation. They can be used with DVT, but only under specific medical guidance. Compression stockings are a standard part of therapy, alongside blood-thinning medications, to manage symptoms and long-term complications following a DVT diagnosis.
The Purpose of Compression in DVT Management
The immediate purpose of compression stockings following a DVT is to manage acute symptoms, primarily swelling (edema). A clot obstructs the normal return of blood to the heart, causing increased pressure and fluid accumulation in the tissues. Compression garments counteract this fluid pooling by gently squeezing the limb, helping to push excess fluid back toward the body’s core.
This external pressure reduces the diameter of distended veins, which increases the velocity of blood flow through open channels. By improving venous return, the stockings relieve the discomfort, heaviness, and pain associated with acute DVT. Compression stockings do not dissolve the blood clot itself; that is the role of anticoagulant medications (blood thinners), which are the primary treatment for DVT. The stockings function as a supportive measure to alleviate symptoms and reduce strain on the venous system.
Preventing Post-Thrombotic Syndrome
The most significant long-term justification for wearing compression stockings after a DVT is the prevention of Post-Thrombotic Syndrome (PTS). PTS is a chronic complication developing in up to 40% of DVT patients, causing chronic pain, swelling, and skin changes. The original blood clot damages the delicate one-way valves inside the veins, allowing blood to flow backward and pool.
This pooling results in persistently high pressure inside the veins, known as venous hypertension. Chronic pressure damages surrounding tissue, leading to discoloration, skin hardening, and potentially venous ulcers. Consistent use of medical-grade compression stockings helps maintain lower venous pressure by mechanically supporting vein walls. Although studies on routine use to prevent PTS are inconsistent, many clinicians still recommend them to manage symptoms and potentially reduce the syndrome’s severity.
Proper Selection and Usage Guidelines
Successful use relies on choosing the correct pressure level and ensuring an accurate fit. Compression is measured in millimeters of mercury (mmHg); medical-grade stockings for DVT management typically start at 20–30 mmHg or 30–40 mmHg. The pressure is graduated, meaning it is tightest at the ankle and gradually decreases up the leg, which is essential for pushing blood toward the heart.
Measurement and Fit
Prescription-grade compression stockings must be professionally measured, ideally in the morning before swelling sets in. A trained professional measures the ankle, calf, and sometimes the thigh, to ensure the garment applies the precise graduated pressure required. Over-the-counter support hose, which usually offer less than 20 mmHg, are not sufficient for therapeutic DVT management.
Duration of Wear
Patients are generally advised to wear the stockings daily, putting them on in the morning and taking them off before bed. Following a DVT, continuous daily wear is often recommended for at least one to two years to mitigate the risk of Post-Thrombotic Syndrome. Proper donning techniques are necessary to ensure the stocking is smooth, wrinkle-free, and avoids creating tourniquet effects.
Critical Safety Considerations
Compression stockings should never be initiated without first consulting a healthcare provider, especially following a DVT diagnosis. A confirmed diagnosis and the commencement of anticoagulant therapy are prerequisites before starting compression.
The most serious contraindication is severe peripheral arterial disease (PAD), where arterial blood flow to the limb is already compromised. Applying external pressure with severe PAD can further restrict arterial flow, potentially leading to tissue damage. Physicians typically check the Ankle-Brachial Pressure Index (ABPI) to ensure arterial circulation is adequate before prescribing compression.
Other conditions, such as uncontrolled heart failure or massive leg swelling due to other causes, may also make compression dangerous or ineffective. Patients should immediately contact their doctor if they experience signs like numbness, discoloration, increased pain, or coldness in the toes while wearing the stockings. These symptoms could indicate a problem with circulation or fit.