A venous leg ulcer is an open sore on the lower leg caused by pressure building up inside the leg’s own veins, and where compression is used well a large share of them close within about twelve weeks. The wound is the visible end of a circulation problem that has usually been developing quietly for years.
What surprises most people is that the injury which seemed to start it (a knock against a car door, a scratch, a rubbed heel from new shoes) is rarely the reason it stays open. This guide covers what a venous leg ulcer actually is, what marks one out from other leg wounds, how long healing usually takes, the six things that most often hold it up, and what changes the outlook.
On this page
- What is a venous leg ulcer?
- The cut did not cause it, the veins did
- What marks an ulcer out as venous
- How long does a venous leg ulcer take to heal?
- Why compression does most of the work
- Six things that hold healing up
- When it needs quick attention
- What helps between appointments
- What to steer clear of
- Living with a venous leg ulcer
- When to have it looked at
- Questions patients ask
- The takeaway
What is a venous leg ulcer?
A venous leg ulcer is a break in the skin below the knee that will not close because blood is failing to drain out of the leg properly. It is by some distance the most common kind of leg ulcer, and it accounts for the majority of the long-standing wounds that turn up on the lower leg.
The mechanics are ordinary enough. Veins in the leg carry blood back up toward the heart against gravity, helped along by a series of one-way valves and by the calf muscle squeezing with every step. When those valves start to leak, blood slips back down and gathers around the ankle. Pressure inside the veins rises and stays high, a state clinicians call venous hypertension: sustained high pressure in the leg veins, which is a separate thing from high blood pressure in the arteries. Fluid and blood cells are forced out into the surrounding tissue. The skin becomes swollen, inflamed and fragile, and at some point it gives way.
Once the skin has opened, that same pressure holds it open. This one fact explains nearly everything about how these wounds behave: why they appear at the ankle, why they weep so heavily, why they can sit unchanged for months, and why the treatment that works is aimed at the leg as a whole and not at the wound bed alone.
The cut did not cause it, the veins did
Nearly everyone can name the moment their wound started. A shopping bag caught the shin. A dog’s claw scratched the ankle. A blister formed on a long day out and never quite went away.
The trigger is real, and it is also beside the point. Skin that has spent years under venous pressure is thin, waterlogged and badly supplied with the raw materials for repair. It breaks at the first excuse, and it cannot rebuild itself while the pressure behind it stays high. The same knock on a healthy leg scabs over inside a week and is forgotten.
This changes what treatment is for. Dressings protect the surface, manage the fluid coming out and keep the wound bed at a workable moisture level, all of which is necessary and none of which touches the reason the wound exists. An ulcer dressed conscientiously every week for six months, with nothing done about the pressure in the leg, will very often still be there at the end of those six months. The wound sits downstream of the problem, and treatment has to reach upstream.
The underlying condition has a name of its own, chronic venous insufficiency, and it is worth reading about separately from the wound, because it explains the swelling, the aching and the skin changes that came first. The National Library of Medicine keeps a plain-language page on venous insufficiency that describes the same mechanism in a few short paragraphs.
What marks an ulcer out as venous
Position is the strongest single clue. These wounds sit low, most often on the inner ankle or in the band of skin running from the ankle bone up to mid-calf. An ulcer on the toes, the heel or the outer border of the foot is pointing somewhere else entirely.
The skin around it has usually been changing for a long time already. Brown or rust-colored staining spreads across the lower leg, left behind by iron from blood cells that leaked into the tissue. Swelling settles overnight and builds again through the day. Dry, itchy, flaking patches appear and behave like eczema. The skin over the lower calf can feel tight and oddly woody under the fingers, and when that hardening is extensive the leg narrows above the ankle while the calf above it stays full.
Pain follows its own pattern. Aching and heaviness build through the day, are at their worst after long periods standing still, and ease within minutes of putting the leg up. Drainage is often generous, sometimes enough to soak a dressing overnight, since that fluid is the same fluid being squeezed out of the veins. Pulses at the ankle are usually still easy to find, because the arteries bringing blood in are not the part that has failed.
None of these signs settles the question by itself, and legs carrying more than one problem at once are common. Telling the three main kinds apart comes down mostly to where the wound sits and how it hurts, which our page on leg ulcer types works through feature by feature.
How long does a venous leg ulcer take to heal?
With effective compression in place and the swelling brought down, many venous leg ulcers close inside twelve weeks, and a good proportion of the rest close by around six months. Those are averages across large groups of people, and an individual leg can sit well outside them in either direction.
Three things shift the odds more than anything else: how big the wound is, how long it has already been open, and how much the person moves. A small ulcer of a few weeks’ standing on someone who walks daily is a different proposition from one that has been open for two years on a leg that rarely leaves a footstool.
The four-week mark is the one clinicians watch. An ulcer that has shrunk by roughly forty percent of its area after a month of proper treatment is very likely to go on and close. One that has barely moved in that time is signaling that something in the plan needs to change, and waiting another three months to find out is time nobody gets back.
How the timeline usually runs
- First two weeksSwelling drops, drainage heavy
- Around week four40% smaller predicts closure
- By week twelveMany wounds have closed
- By six monthsMuch of the remainder
- Open beyond thatCause rechecked, biopsy considered
- Once it closesCompression continues long term
A typical pattern, not a schedule. Wound size, how long it has been open and how much you walk move every one of these.
The last line of that timeline is the one people are least prepared for. Closing the wound does not repair the valves that let the pressure build in the first place, so the leg that produced one ulcer is still a leg capable of producing another. Recurrence within a year is common where compression stops at the moment the skin closes, and much less common where it carries on.
Why compression does most of the work
Compression is the treatment for a venous leg ulcer. Dressings, creams and everything else in the cupboard are supporting acts.
Graduated compression means firm pressure applied at the ankle, easing as it travels up the calf. Applied properly it pushes back against the pressure inside the veins, drives swelling out of the tissue, narrows the veins enough that the leaking valves work a little better, and makes each step of the calf muscle count for more. Bandages are usually built up in layers by a clinician; once the wound has closed, a fitted stocking takes over the same job.
Before any compression goes on, the arteries in that leg get measured. Firm pressure on a limb whose blood supply is already reduced can cause real damage, so ankle and arm pressures are compared to produce a ratio. That figure decides whether full compression is safe, whether a reduced version is used under closer supervision, or whether it is left off altogether. What each result band means in practice is set out on our page about the ankle-brachial index. Where the supply turns out to be the dominant problem, the wound is behaving as an arterial ulcer, and the whole plan changes.
Patients often ask why the bandaging feels tighter than seems reasonable. The honest answer is that weak compression does very little. The pressures used are the ones shown to shift swelling and close wounds, and a bandage loose enough to be forgotten about is usually loose enough to be pointless. Discomfort in the first day or two is expected. Pain that builds, throbs, wakes you, or arrives with numbness or a change in the color of the toes is not, and that bandage should come off and be reported the same day.
Six things that hold healing up
When a venous ulcer refuses to close, the reason is nearly always one of a short list of culprits, and most of them can be corrected once someone has identified them.
Compression that is not doing its job heads the list. It slips down the leg between visits, goes on at the wrong tension, comes off at night and does not go back on, or it was swapped for something gentler after a complaint about discomfort and never swapped back. A stocking that has been washed for a year has lost much of its stretch and is quietly delivering a fraction of the pressure printed on its label.
An arterial problem nobody has measured is the second. Reduced blood supply is common in the same age group, it can sit alongside vein disease in the same leg, and it caps how much healing is possible however good the dressings are. It also makes firm compression unsafe. A leg wound redressed month after month without anyone checking the pressures behind it is the situation to query.
Swelling that never fully comes down keeps the tissue waterlogged and starves the wound edge of oxygen. Heart, kidney and thyroid conditions all contribute here, as do some blood pressure medicines, and a leg that stays puffy despite good bandaging deserves a look beyond the leg itself.
A calf pump that has stopped pumping is the quietest of the six. The calf muscle is what actually moves blood up the leg, and it only works through the ankle bending as you walk. Someone who has become less mobile, or whose ankle has stiffened toward immobility after years of swelling, has lost that pump. Ankle exercises and walking are prescribed for this reason and not for general fitness.
A wound bed loaded with dead tissue, or carrying a genuine infection, is the fifth. Yellow stringy tissue and thickened film across the surface both block new tissue from advancing and generally need removing. Infection is a separate question from the bacteria found on a swab, since every open wound has bacteria living in it and most of them are doing no harm at all.
Last is the vein problem itself never being addressed. Where leaking valves sit in the surface veins, a keyhole procedure to close those veins can, in suitable patients, shorten the time to healing and reduce the chance of the ulcer returning. Not everyone is a candidate and it does not replace compression, but it is a conversation worth having instead of assuming bandages are the only option on the table.
When it needs quick attention
Most venous leg ulcers are slow, stable and unglamorous, and they are managed perfectly well at a weekly appointment. A few situations break that pattern.
Redness climbing away from the wound edge, a raised temperature, shaking chills, or feeling suddenly unwell in yourself all warrant medical attention the same day. Skin infection spreading through the surrounding tissue moves faster than a wound does and is treated urgently. Pain that has changed character, particularly an ache that has turned sharp or that no longer settles when the leg goes up, deserves the same speed of response.
Bleeding from around a venous ulcer can be surprisingly brisk, because the veins under that skin are under pressure. Lie down, raise the leg above the level of the heart and press firmly over a clean pad. It nearly always stops. Bleeding that will not settle with fifteen minutes of that needs emergency care.
A wound that has grown noticeably over two weeks of treatment, that has turned black at the base, or that begins to smell strongly when it did not before, should be seen ahead of the next scheduled appointment. So should a leg that has become cold, pale or dusky, which points at the blood supply and not at the veins.
What helps between appointments
Daily habits carry more weight here than in most wound care, because the pressure inside the leg responds to what you do with it hour by hour.
Raising the leg above the level of your heart takes the gravity load off the veins directly. Thirty minutes at a time, three or four times a day, does considerably more than a token cushion under the calf in the evening, and propping the foot of the bed a few inches keeps it going overnight. Walking matters just as much for a different reason, since every stride works the calf pump. If distance is limited, sitting and pointing the toes up and down twenty or thirty times an hour still moves blood in a leg that cannot easily go anywhere.
Keep the compression on as prescribed, including overnight if that is what you were told, and speak up early if it is unbearable instead of quietly abandoning it. Look after the skin of the whole lower leg and not only the wound, using a plain unscented moisturizer, since the dryness and itch around these ulcers are part of the same condition and scratching creates the next wound.
Eating properly does real work during healing. Repair needs protein and enough calories to build with, and appetite in older patients on long treatment courses often quietly falls away. Stopping smoking helps every part of this. Where diabetes is in the picture, steady glucose control supports the same repair machinery.
What to steer clear of
Do not take the compression off because it feels tight and then say nothing at the next visit. Tightness in the first day or so is normal, and the useful conversation is about whether it can be adjusted, not about abandoning it. Severe pain, numbness or toes changing color are the exception, and there the bandage comes off straight away and the clinic hears about it the same day.
Avoid long stretches standing still, and long stretches sitting with your feet on the floor. Both let blood pool in exactly the place you are trying to clear it from, and standing still is worse than walking for the same length of time.
Keep antiseptics, disinfectants and household cleaning products away from the wound. They damage the fragile new cells doing the repair and buy nothing in return. The same caution applies to scented creams, herbal preparations and over-the-counter antibiotic ointments, for a reason specific to this condition: skin around a venous ulcer becomes unusually prone to allergic reactions, and a rash brought on by a product applied with good intentions can set healing back by weeks.
Resist the urge to pick at yellow or crusted tissue in the wound, and resist scratching the itchy skin around it however maddening it becomes. Report the itch instead, since it usually responds to treatment. And do not push for antibiotics simply because a swab grew something. Bacteria live in every open wound, and treating a laboratory result in place of an actual infection breeds resistance without moving the wound.
Living with a venous leg ulcer
The clinical account leaves out most of what makes these wounds hard, which is that they last for months and intrude on nearly everything.
Bandages do not fit inside ordinary shoes, so people end up in one battered sneaker and one sandal, and that alone stops some of them going out. Showering turns into a planning exercise. Fluid soaks through in the night and ruins the sheets. The ache and the itch break sleep, and broken sleep makes everything else heavier. Appointments every week for half a year eat into work and into whatever else the week was meant for. Plenty of people quietly stop seeing friends somewhere in the middle of all this.
None of that is a side issue, and none of it calls for being stoical in the consulting room. Compression that is genuinely intolerable gets abandoned at home, and an abandoned bandage heals nothing, so saying plainly that you cannot live with the current arrangement usually produces a better one. Different bandage systems, wraps you can adjust yourself, better absorbency to stop the leaking, and treatment aimed at the itch are all things a clinic can offer, and none of them reach the person who says everything is fine.
The other thing worth naming is how long this feels. Twelve weeks is a long time when you are the one changing the dressing, and six months is longer still. Knowing at the outset that slow is normal, and that slow is not the same as failing, takes some of the weight out of the waiting.
When to have it looked at
Any wound on the lower leg still open after two to four weeks should be assessed, and assessed by someone who will measure the circulation instead of simply redressing it. That single step is what separates a wound with a plan from a wound with a dressing.
Ask for a review sooner if the wound is growing, if the drainage or the smell has changed, if the pain has increased, or if the leg is more swollen than it was. An ulcer treated for three months without meaningful progress justifies a fresh opinion on the cause, including whether anything other than venous disease is involved.
Same-day care is for a raised temperature, chills, redness spreading up the leg, rapidly worsening pain, or bleeding that will not stop.
Questions patients ask
How long does a venous leg ulcer take to heal?
Many close within about twelve weeks once compression is in place and the swelling is under control, with a good share of the remainder closing by around six months. Large ulcers, and ones already open a long time, generally take longer. Progress at four weeks is the earliest reliable indication of which way a particular wound is heading.
Can a venous leg ulcer heal without compression?
Some do, and fewer of them, far more slowly. Compression addresses the pressure that caused the wound, which is why it outperforms dressings alone by a wide margin. Where compression cannot be used safely, most often because the arterial supply is too poor, the plan is rebuilt around that limitation instead of proceeding without one.
Why does my leg ulcer keep coming back?
Because closing the skin does not repair the valves. The leg that produced one ulcer still carries the same raised pressure inside it afterward, and skin over that pressure stays vulnerable. Wearing the prescribed compression stocking after healing is the most effective thing known to reduce recurrence, and treating the underlying vein reflux can help further in suitable patients.
Should I walk on it or keep it raised?
Both, at different times of day. Walking works the calf muscle, which is what actively pushes blood back up the leg. Raising the leg above heart level lets gravity drain it while you rest. The combination beats either one alone, and the position to avoid is the middle one: standing still, or sitting for hours with your feet down.
Can I shower with a venous leg ulcer?
Usually yes, with the arrangement your clinic gives you, which often means a waterproof cover over the bandage or timing the shower for just before a dressing change. Ask directly, because the answer depends on the bandage system you are wearing. Soaking the leg in a bath is a different matter and is generally discouraged.
Does a venous leg ulcer mean I need vein surgery?
Not necessarily. Compression remains the foundation of treatment either way. Where a scan shows leaking valves in the surface veins, a minimally invasive procedure to close them can shorten healing and lower the chance of the wound returning, and it is reasonable to ask whether you are a candidate. Deep vein damage is managed differently, so the scan comes before the conversation.
The takeaway
A venous leg ulcer is a pressure problem wearing the costume of a wound. Failing valves let blood pool around the ankle, the pressure climbs, the skin gives way, and no amount of careful dressing changes that arithmetic on its own.
Compression is what shifts it, once the arteries have been checked and cleared for it. Many wounds close inside twelve weeks on that footing, and the four-week point tells you early whether yours is on track. When healing stalls, the reason is usually compression that is not working as intended, an unmeasured circulation problem, swelling that has not come down, a calf pump gone quiet, dead tissue or infection, or vein disease that has never been treated in its own right.
And when it closes, the leg has not been cured. Keeping the stocking on is what stops the next one.
Has your leg wound stopped making progress?
A wound dressed for weeks without shrinking needs its cause looked at, not another dressing. An assessment can establish whether the veins are behind it, whether compression is safe on that leg, and what the plan should be from here.
Circulation testing, compression bandaging, wound bed preparation and the stocking plan that follows healing are handled inside our chronic wound treatment service, where the wound and the leg behind it are assessed together.
This article is general education and does not replace a clinical assessment. Compression strength for any particular leg is settled after the circulation has been measured in person, and no bandage or stocking should be started, altered or left off on the strength of a web page. Bleeding that will not stop, redness climbing the leg, or a sudden change in the color or temperature of the foot needs attention the same day.
