Compression Therapy
Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPod, October 2026
Compression therapy puts firm pressure on your leg and foot, using bandages, stockings, wraps or devices, to help blood and fluid move back up your leg. It is the first-line treatment for venous leg ulcers (slow-healing sores linked to vein problems), and is also used for leg swelling, varicose veins and lymphoedema. In hospital, stockings help prevent blood clots. You need your blood flow checked before you start, because compression can be dangerous if the blood supply to your leg is poor. Done well, it heals more ulcers and eases pain.
What is it?
Compression therapy puts firm pressure on your leg and foot. This helps blood and fluid move back up your leg towards your heart. It can be done with bandages, stockings, tights, wraps or devices.
The pressure is graduated. It is snuggest at the ankle and gets lighter as it goes up your leg. This gives your calf muscles something firm to push against, so they can pump blood up through your veins (the vessels that carry blood back to your heart). When bandages are put on with even tension, this pattern happens naturally, with the most pressure at the ankle.
There are several kinds. They include multilayer bandages (elastic or inelastic), compression stockings, hook-and-loop wraps and devices such as intermittent pneumatic compression. Stockings come in classes, measured in mmHg (a unit of pressure). Class 1 (14 to 17 mmHg) gives light support, and higher classes give firmer pressure.
What is it used for?
The main use is for venous leg ulcers. These are sores on the lower leg linked to problems with the veins. Compression is the first-line treatment, and it is the standard way of treating them without surgery.
It is also used for:
- swelling in the legs, including lymphoedema (long-term swelling from fluid build-up)
- varicose veins and chronic venous insufficiency (veins that don't move blood back up the leg well)
- recovery after some surgery
- helping prevent deep vein thrombosis (DVT, a blood clot in a deep leg vein) in people in hospital, mostly after surgery
If you are being admitted to hospital or having surgery, ask your care team whether stockings are advised for you.
Is it right for me?
Compression suits many people with vein problems. That includes venous leg ulcers where the arteries are healthy, varicose veins, leg swelling, and swelling in people who are up and walking around. It should be prescribed by a health professional, who checks it is safe for you and that it fits.
Before you start, your practitioner will check the pulses in your feet and ankles. If they are weak, they will measure your ABPI (ankle-brachial pressure index, which compares blood pressure at your ankle with your arm). This matters because poor blood flow to the leg can make compression harmful. Depending on the result, you may have firmer compression, lighter compression, or compression may wait until your blood flow has been looked into. If you have severely reduced blood supply or significant peripheral arterial disease, you shouldn't use compression without specialist advice. Stockings aren't suitable if blood flow to the leg is severely reduced, although specialists sometimes still use devices or low-pressure bandages.
Compression should not be put on if you have any of these:
- an infection in the leg or foot
- signs of sepsis
- a limb that isn't getting enough blood
- a suspected DVT
- a suspected skin cancer
- bleeding varicose veins
- signs of heart failure suddenly getting worse
Mild heart problems on their own don't rule compression out. It isn't recommended with severe heart failure, and routine stockings aren't suggested with heart failure that is moderately severe.
Tell your practitioner if you have diabetes, numbness in your legs, heart problems, arterial disease, a past DVT or any skin problems. Don't buy strong compression for yourself if any of these apply. Children and arms need specialist advice.
What happens?
Your practitioner will check your legs, your pulses and your general health. Some services start with light compression (20 mmHg) on both legs if there are no warning signs, and finish a full leg and blood flow check within 14 days.
For a venous leg ulcer, you may be offered class 2 to 3 socks or wraps, a hosiery kit, or a bandage routine. Hosiery kits are often the first choice once your legs have been fully assessed, and bandages are used when kits aren't suitable. Class 1 socks may be used for mild disease or a small wound. The lowest class that works is preferred, because it is easier to keep wearing.
If you have no arterial disease, the usual aim for a venous leg ulcer is about 30 to 40 mmHg at the ankle. For an active ulcer, some guidance recommends at least 40 to 60 mmHg, because higher pressure heals better. Your practitioner chooses the pressure for you.
Bandages should be put on by a trained person. Padding sensitive areas and looking after your skin help prevent pressure damage. How long you need compression, and how many hours a day you wear it, depends on your legs, and your practitioner will advise you. Ask them how to put garments on, and arrange a follow-up review.
How well does it work?
For venous leg ulcers, compression heals more ulcers than no compression. It probably speeds up complete healing and lowers pain, and it may improve quality of life. Bandages and stockings heal ulcers at similar rates, and it isn't yet clear which system is best.
Pressure matters. Higher pressure heals active ulcers better, but only about 10 per cent of bandage applications reach the target pressure, most often because they are too loose. That is why a trained person should apply them.
Stockings help prevent DVT in people in hospital, and there are fewer clots with them than without. This comes from people in hospital, mostly after surgery, so it doesn't show that everyday stockings prevent clots in other people.
For lymphoedema, compression is widely used and may reduce swelling-related infections and repeated cellulitis (a skin infection). For varicose veins and chronic venous insufficiency, compression improves symptoms and swelling, even at low pressures. For post-thrombotic syndrome (ongoing leg symptoms after a DVT), it isn't clear yet whether stockings help. Intermittent pneumatic compression devices may ease symptoms.
Risks and side effects
Compression is generally safe when it is put on correctly and your risks have been checked first. The most common problems are skin irritation and itching.
Bandages applied incorrectly can cause pressure damage, including pressure sores, skin damage and nerve damage. Stockings that are applied badly can cause discomfort, swelling, a DVT or poor blood flow to the leg.
Rare but serious problems include:
- heart failure getting worse
- blood clots in veins or arteries
- skin death
- nerve damage, most often to the nerve near the outside of the knee, which causes foot drop (trouble lifting the front of your foot) with numbness
The warning signs to act on are listed at the end of this page.
Afterwards
Check your skin and toes every day, and each time you take your compression off. Keep your clinic's contact details handy so you can call early if something changes.
Wear your compression as advised, and replace stockings every 3 to 6 months so they keep their support. Keep your follow-up appointments so healing can be checked. If an ulcer or swelling isn't improving as expected, or gets worse, ask your treating team to review it rather than waiting.
Once an ulcer has healed, class 3 stockings may reduce the chance of it coming back over the next six months.
When to see a podiatrist
When to book
Book an appointment with your podiatrist or GP if you have a leg ulcer, leg swelling or varicose vein symptoms and want to know whether compression suits you, or if your ulcer or swelling isn't improving or is getting worse. Book too if your garment or bandage doesn't seem to fit, for example if it feels tightest higher up the leg or rolls over at the top. If you notice itching, redness, a break in the skin or a change in pain while using compression, tell your GP or podiatrist without delay.
When to get help sooner
Call your local emergency number if you suddenly become short of breath, have chest pain, or cough up blood, and take off your compression. Call your local emergency number if your leg, foot or toes suddenly turn cold and pale or blue, with pain or numbness, or if you suddenly can't move your leg or foot, or if you have heavy bleeding from a varicose vein. If you have a leg or foot infection and you also feel very unwell, with confusion or slurred speech, severe shivering or muscle pain, severe breathlessness, mottled or discoloured skin, or little or no urine, this could be sepsis: call your local emergency number. Don't put compression on in any of these situations.
These need urgent medical assessment: see your GP today, or go to an urgent care clinic or the nearest emergency department. Don't put compression on if you have a red, hot, swollen or painful leg or foot with a fever, a calf that is painful, swollen, warm or red, lighter bleeding from a varicose vein, or foot drop with numbness. The same applies if you have worsening breathlessness, swelling of your trunk (chest and belly), waking up breathless, rapid weight gain or can't lie flat. Also seek urgent help if your foot is pale, cold, blue or mottled, or you have new severe pain, because this may mean poor blood supply.
If your toes turn white, blue, purple or mottled, you have new or increased pain, new numbness or pins and needles, the garment is too tight or painful, or your leg swells or turns red, take the garment or bandage off completely. Don't put it back on, and contact your treating team straight away. If you can't take it off, ask a family member or care agency for help, call a health advice phone line if there is one where you live, or go to the nearest emergency department.
See your GP soon if you notice a new or changing spot or sore on the skin of your leg.
Frequently asked questions
How tight should compression feel?
It should feel firm and snug, and tightest at the ankle, getting lighter as it goes up your leg. If it feels tightest higher up, or it rolls over at the top, it isn't fitting as intended. Ask your practitioner to check it.
Is compression safe if I have diabetes?
Diabetes is listed as a caution for light class 1 stockings unless you are under medical supervision. Loss of feeling in the legs is listed too. So have compression only after assessment by a health professional, and tell them about any numbness in your legs.
What if I can't cope with wearing compression?
Talk to your practitioner rather than simply stopping for good. They can look at other options. You can also ask whether exercise, treating varicose veins or other treatments could be used alongside compression.
Can I buy compression stockings myself?
Compression should be prescribed by a health professional to make sure it is safe for you. Strong compression shouldn't be bought without advice if you have arterial disease, heart problems, diabetes or loss of feeling in your legs.