Anti-embolism stockings are the snug white stockings many people are given around surgery or a hospital stay, meant to stop blood clots forming in the legs while you’re lying still. They work by pressing on the leg from the outside to keep blood in the veins moving rather than sitting still.1PubMed Central. Graduated compression stockings They are a helper rather than a guarantee, and how well they fit and how they are worn decides much of whether they help at all.
Why Hospitals Give You Compression Stockings
People in hospital are more likely to develop a deep vein thrombosis (DVT), a clot in the deep veins of the leg or pelvis.2PubMed Central. Graduated compression stockings for prevention of deep vein thrombosis Long periods of lying still, from an illness or an operation, let blood slow down in the legs.3PubMed Central. Graduated compression stockings for prevention of deep vein thrombosis Compression stockings were introduced to cut that risk during the stay.4PubMed Central. Graduated compression stockings for prevention of deep vein thrombosis The “embolism” in the name comes from what can happen next: a clot in a leg vein can break off and travel to the lungs.
A DVT often shows up as a swollen, sore, warm calf on one side. It can also be silent, which is why prevention is used routinely rather than only when symptoms appear. If a piece travels to the lungs it can cause breathlessness or chest pain, and anyone with these signs should tell staff immediately.
Many hospitals ask about your clot risk on admission. The questions cover the type of surgery, your age and weight, past clots, cancer, pregnancy or a recent birth, and how much you will be able to move. The result decides which protections you are offered: stockings, inflatable sleeves, blood-thinning injections, or a mix. Two people on the same ward can therefore be offered different protection, and that doesn’t mean one of them is being looked after less well.
Typically the stockings go to people having operations, especially longer or major ones, and to people admitted with illnesses that keep them in bed. If you weren’t given them, your assessed risk or health situation usually pointed to a different plan. You can ask staff what it is, and you can equally ask why you were given stockings; it should be explained.
Anti-embolism stockings are designed for people who are mostly lying in bed. Stronger medical compression stockings are made for people who are up and walking, so the two are not interchangeable. In high-risk surgical patients, guidelines pair the stockings with blood-thinning injections or tablets rather than using them alone.5PubMed. Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy
How the Squeeze Keeps Blood Moving
The stockings squeeze hardest at the ankle and less further up the leg.6PubMed Central. Graduated compression stockings That gradient gently pushes blood upward toward the heart. The outside pressure also makes the main leg veins narrower, so the same amount of blood has to travel through a narrower tube and moves faster.7PubMed Central. Graduated compression stockings
The gradient matters because pressure that was tighter at the top would trap blood below it like a band. That is why rolled or bunched stockings are a problem.
This shows up in real legs. In new mothers a day or two after birth, thigh-length stockings narrowed the main thigh vein and raised blood speed in it by about 40% within 30 minutes.8PubMed. The effect of graduated compression stockings on blood velocity in the deep venous system of the lower limb in the postnatal period During operations, calf veins in people without stockings widened to nearly twice the size of those in people wearing them.9PubMed. Deep vein thrombosis: effect of graduated compression stockings on distension of the deep veins of the calf So the stockings seem to work mainly by stopping veins from stretching and filling with slow blood.10PubMed Central. Evidence-Based Compression
When you walk, your calf muscles tighten with each step and squeeze the deep veins, pushing blood up toward the heart. Small one-way valves in the veins stop blood falling back between squeezes, so the muscle pump and the valves work as a team.
In bed, especially after an operation or under anaesthetic, that pumping nearly stops and blood can linger in the calf veins. Blood that sits still in a stretched vein is more likely to clot, which is exactly the situation the stockings are trying to prevent. A stocking cannot copy the pump, but its steady outside pressure replaces part of the support the muscles would otherwise give.
How Well Anti-Embolism Stockings Work
Compared with other mechanical options, stockings are cheap and comfortable.11PubMed. Prevention of venous thromboembolism: focus on mechanical prophylaxis They appear less effective, though, than intermittent pneumatic compression, inflatable sleeves that squeeze and release the legs.12PubMed. Prevention of venous thromboembolism: focus on mechanical prophylaxis The sleeves actively empty the deep veins, while stockings mainly stop them widening.13PubMed Central. Evidence-Based Compression For higher-risk surgery, stockings are therefore usually one part of a package with blood thinners or sleeves.14PubMed. Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy
The sleeves wrap the calf or thigh and fill with air in cycles, squeezing and then letting go. Stockings apply constant pressure instead. The sleeves need a power source and tubing, so they are usually used in bed or in a chair. Stockings can stay on through the night and on trips to the bathroom, a practical advantage even if they are less powerful.
Stockings lower risk but don’t remove it. Moving your feet and walking when you’re allowed still matters.
Stroke is an exception. In people admitted with stroke, thigh-length stockings left the clot rate essentially unchanged, about 10% with or without them.15PubMed. Effectiveness of thigh-length graduated compression stockings to reduce the risk of deep vein thrombosis after stroke (CLOTS trial 1): a multicentre, randomised controlled trial Skin breaks, blisters and ulcers, however, were about five times as common with the stockings, 5% versus 1%.16PubMed. Effectiveness of thigh-length graduated compression stockings to reduce the risk of deep vein thrombosis after stroke (CLOTS trial 1): a multicentre, randomised controlled trial Many stroke units no longer use them routinely.
Results differ between groups for understandable reasons. Stroke patients may have weak legs and poor feeling, so skin damage goes unnoticed. A benefit shown in surgery doesn’t automatically carry over to every illness, because surgical patients are often more mobile and have normal feeling in their legs. If you or a relative has had a stroke and has been offered stockings, it is reasonable to ask what the team is using in their place, such as sleeves or medicines.
Knee Length or Thigh Length
Thigh-length stockings appear somewhat more effective after surgery.17PubMed Central. Thigh length versus knee length antiembolism stockings for the prevention of deep vein thrombosis in postoperative surgical patients; a systematic review and network meta-analysis Even so, across combined trials about 2% of people in knee-length stockings developed a clot versus about 5% in the thigh-length groups.18PubMed. Knee versus thigh length graduated compression stockings for prevention of deep venous thrombosis: a systematic review Knee-length stockings can be as effective, and they cost less.19PubMed. Knee versus thigh length graduated compression stockings for prevention of deep venous thrombosis: a systematic review
People find both lengths hard to use, but fewer report discomfort with knee length.20PubMed Central. Thigh length versus knee length antiembolism stockings for the prevention of deep vein thrombosis in postoperative surgical patients; a systematic review and network meta-analysis People also prefer knee length and wear it correctly more often.21PubMed. Systematic review of patient preference and adherence to the correct use of graduated compression stockings to prevent deep vein thrombosis in surgical patients In practice, a stocking you keep on properly may matter more than its length.22PubMed. Systematic review of patient preference and adherence to the correct use of graduated compression stockings to prevent deep vein thrombosis in surgical patients
Thigh-length ones go wrong in predictable ways. The top band sits on the soft, mobile skin of the thigh and tends to slip down or curl over as you move in bed. A band that rolls over itself becomes a tight ring that squeezes harder than the rest of the stocking. The extra length also gives more fabric to wrinkle, particularly behind the knee where the leg bends, and wrinkles press into the skin.
If you’re offered one length, ask why it was chosen. If a pair keeps slipping, say so, because swapping may help. Don’t cut or fold down a thigh stocking to make it knee length, since that creates exactly the tight ring you want to avoid.
Side Effects and Who Shouldn’t Wear Them
Common complaints are difficulty putting them on, heat, curling, redness, sweating and itching.23Ordu Üniversitesi Hemşirelik Çalışmaları Dergisi. Assessment of Information Needs, Practices, and Challenges Encountered by Patients in Postoperative Period Regarding the Use of Anti-Embolism Stockings Stockings that are too small, rolled or folded can irritate the skin and in severe cases cause ulcers.24Caring Touch Medical. What are the Side Effects of Compression Stockings? One that slips out of position can create very high local pressure and damage tissue.25PubMed Central. Risks and contraindications of medical compression treatment – A critical reappraisal. An international consensus statement A badly worn stocking can even act like a tourniquet, slowing blood and possibly raising clot risk instead of lowering it.26OR Manager. What Are Anti-Embolism Stockings and How Do They Work?
Some warning signs should be reported while you wear them:
- Circulation: new numbness, tingling, coldness, or pale or bluish toes can mean the stocking is restricting blood flow, and staff should be told straight away.
- Skin: blisters, broken skin or deep red marks are most likely at the heels, over bony areas and under the top band.
- Pain: pain under the stocking that wasn’t there before may signal pressure damage or a fold in the fabric.
Skin under the stockings should be checked at least once a day, by you, a relative or a nurse. Numb legs raise the stakes. Pressure damage normally announces itself as pain, and without feeling that warning doesn’t come, so stroke and diabetic nerve damage raise special concern. A relative can help by looking at the skin and heels each day if you can’t see or feel them well.
Some people shouldn’t wear them at all. Peripheral arterial disease, meaning narrowed arteries supplying the legs, rules these stockings out.27PubMed Central. Unseen but present danger: improving the safe prescribing of anti-embolism stockings (AES) Squeezing a leg with poor arterial blood supply can starve the skin of blood. Severe heart failure, nerve damage from diabetes with loss of feeling, and a confirmed allergy to the material are also reasons not to use compression.28Phlebolymphology. Risks and contraindications of medical compression treatment Tell staff if you have leg pain on walking, poor circulation, diabetes with numb feet, or heart failure.
Getting the Right Fit and Wearing Them Properly
Fit often goes wrong. In one hospital audit of surgical patients, about 3 in 10 had the wrong size and nearly 4 in 10 were wearing them incorrectly.29PubMed Central. Use and wear of anti‐embolism stockings: a clinical audit of surgical patients Also, 7 in 10 said nobody explained why they were wearing them.30PubMed Central. Use and wear of anti‐embolism stockings: a clinical audit of surgical patients Legs vary so much that a standard size can fit loosely and fail to give the right pressure pattern.31PubMed. Do anti-embolism stockings fit our legs? Leg survey and data analysis
Measurements are best taken first thing in the morning, standing with feet flat, with a snug tape on bare skin.32Learning Hub NHS. Procedure guideline: Step-by-step guide to measuring and applying antiembolism stockings That catches the leg before swelling builds through the day. Measuring over clothing or bandages gives the wrong size. If you can’t stand, you may be measured lying down, and staff use the same measurements to choose a size from the maker’s chart.
Each leg is measured separately.33Learning Hub NHS. Procedure guideline: Step-by-step guide to measuring and applying antiembolism stockings Legs are rarely identical, particularly after leg surgery or when one is swollen.
Legs should be re-measured after major or leg surgery, when swelling goes up or down, at least every 7 days, and on discharge if taking them home.34Learning Hub NHS. Procedure guideline: Step-by-step guide to measuring and applying antiembolism stockings If your legs look puffier or thinner than before, ask for another measurement rather than waiting for the next scheduled one.
To put them on, turn the stocking inside out down to the heel, slip the foot in, then roll it upward over the leg. The heel patch must sit on the heel. Smooth out wrinkles so there are no folds behind the knee or at the ankle, and never roll the top down.
You can check your own fit. You should be able to slide a finger under the top band without it digging in. A stocking that leaves deep grooves is too tight, while one that keeps sliding down may be too big, so ask for re-measuring. Ask for a new pair if worn ones lose their stretch.
Wearing Them at Home After Hospital
People wear stockings more reliably in hospital, where staff watch them, and less once home.35PubMed. Systematic review of patient preference and adherence to the correct use of graduated compression stockings to prevent deep vein thrombosis in surgical patients In one audit no one received written information about their stockings.36PubMed Central. Use and wear of anti‐embolism stockings: a clinical audit of surgical patients Before discharge, ask for written guidance on how long to wear them and when to take them off.
A simple routine helps. Take them off briefly once a day, usually when washing, so you can look at the skin on your feet, heels, ankles and calves. Wash them by hand in mild soap and let them air dry, as heat from a dryer or radiator wears out the stretch. A second pair lets you wear one while the other dries, so your legs are never left unprotected. When they are off, moisturise dry skin if you wish, but let it dry fully before putting the stockings back on, as damp or greasy skin makes them harder to smooth on and more likely to irritate.
Swelling, pain or warmth in one calf, even while wearing stockings, can be a sign of a clot and needs prompt medical advice. Sudden breathlessness or chest pain is an emergency, so call emergency services rather than waiting to see how you feel. Broken skin, blisters or sores under the stocking should be shown to a nurse or doctor, and the stocking should be left off until it is checked. If you were told to stop wearing them but your legs still swell, ask why, since swelling can have causes that need looking at.