Is Scar Revision Surgery Right for Your Scar? Maturity, Location and Skin Type Explained

The scar is only four centimeters long, but it runs straight across the fold of her elbow, and every time she reaches for a top shelf she feels it tug. It is pale now, flat in places, raised in one stubborn ridge near the middle. Her question is simple and surprisingly hard to answer: is this the kind of scar a surgeon can actually improve?

Whether someone is a good scar revision candidate depends less on how much the scar bothers them and more on three things a clinician can examine: how old and settled the scar is, where on the body it sits, and how that person’s skin tends to heal. Those three variables decide not just whether surgery makes sense, but which technique, and when.

What follows is the conversation a careful surgeon would want to have before anyone books a procedure, stripped of marketing and grounded in what the evidence supports.

What actually happens during scar revision surgery

Scar revision is a procedure that removes or rearranges scar tissue so the wound heals again under better conditions. That phrase, better conditions, is the whole idea. The original wound may have been jagged, infected, stretched by movement or closed in a hurry. A surgeon cannot make skin forget it was injured, but can give it a second attempt at healing with a clean edge, less tension and a more favorable direction.

In the simplest version, the surgeon numbs the area, cuts out the old scar as a narrow ellipse, and closes the new wound in layers with fine sutures. The result is still a scar, just a thinner, flatter, straighter one that is easier for the eye to skip over. MedlinePlus describes this as the core of most revisions: the scar is removed and the skin is closed with careful attention to tension and alignment with natural skin lines.

More complex scars need more than a straight cut. A scar that crosses a joint or a facial contour may be redesigned into a zigzag so it no longer pulls in one direction. A depressed scar may need the tissue beneath it released. A very wide or tight scar may need skin borrowed from elsewhere. These techniques are covered later, but the principle is shared: change the mechanics of the scar so the body produces something quieter.

Most scar revisions are done under local anesthesia, sometimes with light sedation, and many are same-day procedures. Larger or multiple revisions, or those in children, may need general anesthesia. Johns Hopkins notes that the choice depends on the scar’s size, location and the patient’s overall health, and it is always the anesthesia and surgical team’s call.

When is a scar mature enough to revise?

A scar is not finished when the wound closes. Beneath the surface, collagen (the structural protein that forms scar tissue) keeps remodeling for many months. A scar that is red, raised and firm at three months may be pale, soft and flat at fifteen months without anyone touching it. Operating too early means revising a scar that was still going to improve on its own, and the new wound inherits the same restless healing environment.

This is why surgeons talk about scar maturity. A mature scar has stopped changing: its color has settled toward the surrounding skin, its texture is stable, and it no longer itches or tightens. The NHS advises that scars can take up to two years to fade and flatten, and MedlinePlus notes that many surgeons prefer to wait a year or more after the original injury before revising, because the scar’s final appearance is not predictable before then.

There are exceptions, and they matter. A scar that is contracting across a joint and already limiting movement, or one that pulls an eyelid or lip out of position, may be revised earlier because function cannot wait for cosmetics. A surgeon weighs the cost of waiting against the cost of operating on an immature scar, and that judgment is individual.

For a would-be scar revision candidate, the practical message is patient but not passive. During the waiting year, scar massage, sun protection and silicone products are commonly advised, and a clinician can monitor whether the scar is heading toward hypertrophy or keloid, which changes the plan entirely. Marking the anniversary of the injury on a calendar, then reassessing, is a reasonable approach for most people.

Who is a good scar revision candidate, and who is usually asked to wait

Surgeons tend to look for a cluster of features rather than a single qualifying trait. The typical scar revision candidate has a scar that is at least a year old and no longer changing; a scar that is wide, depressed, raised, misaligned with skin lines, or tethered to deeper tissue; a realistic understanding that the goal is improvement, not erasure; and general health that allows wounds to heal well. Non-smokers heal more reliably, and MedlinePlus and Johns Hopkins both list smoking as a factor that worsens surgical scarring.

Functional problems strengthen the case considerably. A scar that restricts a finger, shoulder or neck, distorts a facial feature, or breaks down repeatedly is a different conversation from a scar that is simply disliked. Both can be legitimate reasons to operate, but the first group tends to be prioritized and is more likely to be considered medically necessary by insurers.

Who is usually asked to wait or reconsider?

• Anyone whose scar is still red, firm or actively changing; the clock has not run out.
• People with a history of keloids, especially on the same body region, where surgery alone may make the scar larger.
• Smokers who are not yet ready to stop; many surgeons ask for a smoke-free period before and after surgery.
• People with uncontrolled diabetes, active skin infection near the scar, or conditions that impair healing.
• Anyone who expects the scar to disappear completely; that expectation cannot be met by any technique.

Being asked to wait is not a refusal. Often it means the surgeon wants to see where the scar settles, or wants a dermatologist to try non-surgical steps first. The decision, in every case, rests with the treating team after examination.

Does scar location change what surgery can do?

Enormously. Skin is not the same thickness, tension or mobility across the body, and scar behavior follows those differences closely. Two scars of identical length can have wildly different prognoses depending on where they sit.

The face is generally the most forgiving region. Facial skin has a rich blood supply, heals quickly, and is crossed by natural creases and expression lines that a well-placed incision can hide inside. Scars around the eyes and mouth are the exception: even small tension there can pull a lid or lip out of position, so revisions in those zones are planned with great care and sometimes staged.

The chest, upper back, shoulders and deltoid area are the opposite. These regions sit under constant skin tension from posture and movement, and they are the classic sites for hypertrophic and keloid scars. Mayo Clinic lists the chest, shoulders, earlobes and upper back among the most common keloid locations. A surgeon looking at a sternal or shoulder scar will often advise combination treatment rather than excision alone, and will warn that the revised scar may widen again over time.

Joints introduce a third variable: motion. A scar crossing the elbow, knee, finger or neck is stretched and relaxed thousands of times a day, which encourages widening and contracture (a tightening of scar tissue that limits movement). Here the goal of surgery is often to reorient the scar so it zigzags across the joint line rather than running straight along it, spreading tension across many small segments.

Lower legs deserve a mention too. Blood flow is slower, swelling is common, and wounds there heal more slowly than almost anywhere else, so expectations and recovery timelines are adjusted accordingly.

How skin type and pigment shape the plan

Skin type matters in two separate ways: how much pigment the skin carries, and how aggressively it tends to form scar tissue. Both are partly inherited and neither is a flaw; they are simply variables a surgeon must plan around.

People with more melanin, broadly those with brown or Black skin, have a higher likelihood of developing keloids after injury or surgery. Mayo Clinic notes that keloids are more common in people with brown or Black skin and in those with a family history of keloids. For such a patient, scar revision is not off the table, but a surgeon will usually ask detailed questions about previous scars, piercings and acne marks, and will discuss adjunct treatments and the realistic chance of recurrence before anyone commits.

Pigment also affects color outcomes. Darker skin is more prone to post-inflammatory hyperpigmentation, where healing skin becomes darker than its surroundings, and sometimes to hypopigmentation, where it becomes lighter. Either can make a revised scar more visible than its texture alone would suggest. Strict sun protection during healing reduces, but does not eliminate, this risk, and the NHS specifically advises covering new scars from sunlight for their first year or so.

Very fair skin has its own issues. It shows redness for longer, and scars can stay pink for many months before fading toward white. People who tan easily around a scar may end up with a pale line that stands out against sun-darkened skin.

Age folds into this as well. Younger skin heals vigorously, which sounds like an advantage but often means thicker, redder scars. Older skin, with less tension and more creases, frequently produces finer scars but heals more slowly. A good consultation reads all of these factors together rather than in isolation.

Hypertrophic scar, keloid or wide scar: which type do you have?

Scars are not one thing, and the label a surgeon gives yours predicts both the technique and the odds. The table summarizes the main categories as described by the NHS, MedlinePlus and Mayo Clinic.

Scar type	What it looks like	Typical behavior	Usual surgical approach
Fine-line (normal)	Flat, pale, narrow	Fades over 1–2 years	Rarely needs surgery
Wide or stretched	Flat but broad, often pale or shiny	Stable once mature	Excision and layered closure
Hypertrophic	Raised, red, firm, stays within the wound’s borders	Often flattens over 1–2 years	Wait, non-surgical first; excision if persistent
Keloid	Raised, grows beyond the original wound	Does not regress; may enlarge	Excision only with adjunct treatment
Atrophic or depressed	Sunken, pitted	Stable	Release of tethering, fillers or resurfacing
Contracture	Tight band crossing a joint or feature	Limits movement	Z-plasty, grafts or flaps

The key distinction for a potential scar revision candidate is between hypertrophic scars and keloids, because they can look similar early on. A hypertrophic scar is raised but respects the edges of the original wound and usually improves on its own. A keloid spreads beyond those edges into normal skin, often itches or hurts, and does not shrink with time. The NHS notes that hypertrophic scars generally improve over a couple of years while keloids tend to persist or enlarge. Confusing the two leads to very different treatment mistakes, which is why an in-person examination, and sometimes a period of observation, comes before any decision to cut.

Scar revision for keloids: why excision alone is rarely the plan

Keloids are the scar type where surgery is most tempting and most likely to disappoint if used on its own. A keloid is a scar that grows beyond the boundaries of the original wound, and the biology that produced it is still present in the surrounding skin. Cutting it out creates a new wound in that same overactive environment, and MedlinePlus and Mayo Clinic both warn that keloids frequently return after surgical removal alone, sometimes larger than before.

That does not mean surgery is never appropriate. It means it is almost always paired with something that calms the healing response. Clinicians commonly combine excision with corticosteroid injections into the scar, which reduce inflammation and collagen production; with pressure dressings or clips, which are particularly used on earlobes; with silicone sheeting; or with low-dose radiation delivered shortly after surgery in selected adults. Mayo Clinic describes these combination approaches as the standard way to lower recurrence risk, while being clear that no combination eliminates it.

For many keloids, surgery is not even the first step. Corticosteroid injections alone, repeated over months, can soften and flatten a keloid without any incision, and cryotherapy (freezing the scar) is sometimes used for small lesions. Whether a given patient should start with injections, proceed to excision, or leave the keloid alone is a decision for a dermatologist or plastic surgeon who has seen the scar and heard the history.

If you have had one keloid, you are at higher risk of forming another, which is one of the strongest reasons surgeons ask about piercings, acne scars and old surgical sites before any elective procedure. Telling the team about even a small keloid on an earlobe is genuinely useful information, not an embarrassing footnote.

Which technique fits which scar: excision, Z-plasty, W-plasty, grafts

Surgeons choose among a small number of core techniques, and the choice follows from the scar’s type, location and tension.

Simple excision, described earlier, removes the scar as an ellipse and closes the skin in layers. It suits wide, depressed or poorly aligned scars on skin that is not under heavy tension. The new scar is longer than the old one, because an ellipse must be roughly three times as long as it is wide to close flat, which surprises many patients.

Z-plasty is a technique that cuts the scar and two angled flaps so the tissue can be swapped, changing the scar from a straight line into a Z shape. The redesign lengthens the scar along its original axis and redirects tension, which is exactly what a contracture across a joint or neck needs. MedlinePlus lists Z-plasty among the standard revision methods for scars that pull or restrict.

W-plasty breaks a straight scar into a series of small connected triangles. It does not lengthen the scar much; its purpose is camouflage, because the eye tracks a straight line far more readily than an irregular one. It is often used on the face, where a straight scar crossing cheek lines draws attention.

Skin grafts and flaps come into play when there is not enough healthy skin to close the wound after a large scar is removed. A graft is a sheet of skin taken from elsewhere and laid onto the wound; a flap is tissue moved with its own blood supply still attached. These are larger operations, used for burn scars and extensive contractures, and they create a second scar at the donor site. Johns Hopkins notes that grafts and flaps are reserved for scars that cannot be closed directly.

Tissue expansion, where a balloon is placed under nearby skin and gradually inflated over weeks to grow extra skin, is a further option for very large scars, particularly in the scalp.

Alternatives and adjuncts to scar revision surgery

Surgery sits at one end of a spectrum, and many scars are managed well without it. For a potential scar revision candidate, understanding the alternatives is not a consolation prize; several of them are routinely used alongside surgery to protect the result.

Silicone gel sheets and gels are the most widely recommended first-line option for raised scars. They are thought to work by hydrating the scar and modestly reducing collagen production, and the NHS lists them among standard measures for hypertrophic scars and keloids, usually applied for several months. Pressure garments, familiar from burn care, flatten scars through sustained compression over long periods.

Corticosteroid injections, placed directly into the scar tissue, reduce inflammation and the activity of the cells that lay down collagen. They are repeated at intervals decided by the clinician and are the mainstay of non-surgical keloid treatment. Mayo Clinic describes them as a common first approach for keloids and as a routine adjunct after keloid excision.

Laser treatment can address color rather than shape. Vascular lasers target the red blood vessels that keep a young scar pink, and fractional lasers create tiny controlled injuries that encourage remodeling and smoother texture. Lasers do not remove scars, and results vary with skin type; darker skin carries a higher risk of pigment change, so settings and even the decision to treat are individualized.

Dermabrasion and chemical peels smooth surface irregularity by removing the outer layers of skin, and injectable fillers can temporarily lift depressed scars. Microneedling is increasingly used for acne scarring.

None of these is universally effective, and the evidence base for several is modest. A clinician will often suggest trying one or more before surgery, both because they may be enough and because they reveal how your skin responds to intervention.

How painful is scar revision surgery?

Most people are surprised by how little the procedure itself hurts. The majority of scar revisions are performed under local anesthesia, where the area is numbed with an injected anesthetic. The injection stings for a few seconds; after that, patients typically feel pressure and movement but not pain. For larger revisions, or for people who prefer not to be awake, sedation or general anesthesia may be used, and the anesthesia team will discuss the options at the pre-operative visit.

Discomfort afterward is generally described as soreness, tightness or a bruised feeling at the site rather than sharp pain, and it is usually most noticeable in the first two to three days as the local anesthetic wears off and swelling peaks. MedlinePlus notes that pain after scar revision is usually mild and managed with medicines recommended by the surgeon. Which medicine, how much and for how long are decisions for the prescribing clinician; some common over-the-counter pain relievers increase bleeding and are often avoided around surgery, so it is important to ask rather than assume.

Certain locations are more uncomfortable than others. Scars revised over joints or on the chest may feel tight with movement for several weeks, and scalp or earlobe revisions can be tender because those areas are hard to rest. Itching during healing is common and is a sign of nerve recovery, not a problem in itself, though scratching a fresh wound is unwise.

Pain that increases rather than settles after the first few days, especially with redness, warmth or discharge, is not expected and should prompt a call to the surgical team. The pattern most people describe is a sore first weekend, a tight second week, and then a steady fade.

What the days and weeks after scar revision usually look like

Recovery divides fairly cleanly into phases, and knowing them in advance makes the long middle stretch easier to tolerate.

In the first week, the wound is covered with a dressing, and swelling and bruising around the site are normal. Surgeons usually ask patients to keep the area dry for a day or two, avoid stretching it, and sleep with the site elevated if it is on the face or a limb. Sutures on the face are commonly removed within about a week; those on the body or over joints may stay longer, and some surgeons use dissolving sutures beneath the skin. MedlinePlus describes this early period as the time when the wound is most vulnerable to infection and reopening.

Weeks two through six are the tension phase. The wound has closed, but new collagen is still weak, and the NHS notes that a healing scar does not regain its full strength for many weeks. Heavy lifting, sport and anything that pulls across the scar are typically restricted during this window. Surgeons often begin scar massage and silicone treatment once the skin is fully sealed, usually after the second or third week, and strict sun protection starts immediately and continues for about a year.

From roughly six weeks onward, the scar may paradoxically look worse before it looks better: redder, firmer and more raised as collagen builds. This is expected. Over the following months it softens and fades, and the NHS and MedlinePlus both describe final scar appearance as taking a year or longer to settle.

Judging a revision at three months is, therefore, premature. Most surgeons schedule a review around that point to check direction of travel, and another around a year to assess the actual outcome.

Is scar revision worth it for a typical scar revision candidate?

People ask about the success rate of scar revision expecting a percentage, and honesty requires explaining why no single figure exists. Success depends on what is being measured: a thinner scar, a flatter one, a restored range of motion, less itching, or simply a patient who no longer notices it. Published studies measure different things in different scar types, and no major guideline body offers a pooled success percentage for scar revision as a whole. A clinic quoting one number is quoting its own selected cases, not the evidence base.

What the evidence does support is more useful than a number. Revision reliably converts certain bad scars into better ones: wide scars closed under tension become narrower, misaligned facial scars realigned to skin creases become harder to see, and contractures released with Z-plasty regain movement. These are mechanical changes with predictable mechanisms. Where the evidence is weaker is in scar types driven by biology rather than mechanics, chiefly keloids, where recurrence after surgery alone is common according to both MedlinePlus and Mayo Clinic.

Whether revision is worth it, then, comes down to three questions a scar revision candidate can answer with their surgeon. Is the problem mechanical, such as width, direction or tethering, or biological, such as a keloid tendency? Is the scar mature, so the baseline is real? And is a longer, finer scar, or a zigzag one, a trade the person would make, knowing it will take a year to judge?

For functional scars, the case is usually strong. For purely cosmetic scars, the honest answer is that many people are glad they proceeded and some are not, and the difference lies largely in expectations set before surgery. The treating team is the right place to test those expectations against the specific scar in question.

What people often get wrong about scar revision

The myths around scars are durable, and several of them steer people toward poor decisions.

The first is that scar revision removes scars. It does not, and no technique does. Every incision heals with a scar; the point of revision is to produce a less noticeable one. Anyone promised scar-free results is being misled.

The second is that sooner is better. People often want the scar dealt with while the injury is fresh in their minds, yet operating on an immature scar means revising something that was still improving and that is more likely to heal aggressively again. The NHS timeline of up to two years for a scar to settle is the evidence behind the waiting advice.

Third, that a raised scar is a keloid. Most raised scars are hypertrophic and will flatten on their own. True keloids spread beyond the original wound and do not regress. The distinction decides whether surgery is a reasonable first step or a risky one.

Fourth, that insurance decisions are about appearance. In practice, coverage usually hinges on documented functional impairment, such as restricted movement, pain, recurrent breakdown or distortion of a feature, rather than on how a scar looks. Policies vary widely and pre-authorization is typically required; the surgeon’s office can explain what documentation is needed, and the answer will differ for every plan.

Fifth, that vitamin E oil or over-the-counter scar creams reliably improve scars. The evidence for most topical products is weak, and some people develop skin irritation from vitamin E. Silicone is the one over-the-counter approach with reasonable support, as the NHS notes.

Finally, that a bad result means the surgeon failed. Scars are partly genetics, partly location and partly luck. Even a technically perfect revision can widen or redden in skin that is prone to it, which is exactly why candidacy is assessed so carefully.

Questions to ask your care team before deciding

A consultation goes better when the patient arrives with specific questions. These are the ones that tend to surface the information that matters.

• What type of scar do I have, and is it mature enough to revise now, or would you prefer to wait?
• Given where the scar is and how my skin heals, what realistic change in width, height and color do you expect?
• Which technique are you proposing, and will the new scar be longer or a different shape than the current one?
• Do I have features that raise my keloid or hypertrophic risk, and if so, what adjunct treatments would you combine with surgery?
• Would you recommend trying silicone, injections or laser first, and what would tell us those have done enough?
• What anesthesia will be used, and what should I expect for discomfort in the first week?
• Which activities will be restricted, for how long, and when can I return to work, exercise or lifting?
• What will the scar look like at three months compared with a year, so I do not judge it too early?
• What signs after surgery should make me call you the same day?
• If the result is not what we hoped, what are the options, and how long would you wait before considering them?

Two further questions are worth asking yourself rather than the surgeon. Would I be content with a scar that is fifty percent less noticeable but still present? And am I ready to protect the new wound from sun, strain and smoking for the full year it needs? If the answer to either is no, waiting is not a defeat; it is good timing. Whatever you decide, the final recommendation about whether and how to proceed belongs with the surgeon who has examined the scar.

When to call your doctor

Most scar revisions heal without incident, but a small number of problems need prompt attention, and the first two weeks are when they tend to appear. Contact your surgical team the same day if you notice any of the following, and seek urgent care if symptoms are severe or you cannot reach the team.

• Spreading redness, increasing warmth or swelling around the wound after the first two or three days, rather than gradual settling.
• Pus, cloudy or foul-smelling discharge, or a wound edge that opens or gapes.
• Fever or chills, which can signal infection even when the wound itself looks only mildly inflamed.
• Bleeding that soaks through the dressing or does not stop with ten minutes of firm pressure.
• Pain that worsens over time or is out of proportion to what the surgeon described.
• Numbness, tingling or weakness beyond the immediate scar area, particularly after revisions on the face or over joints.
• Dark, dusky or blackened skin at the wound edges or on a graft or flap, which can indicate poor blood supply.

Later concerns deserve a call too, even if they are not emergencies. A scar that starts to grow beyond the incision line, becomes increasingly raised and itchy after the first couple of months, or begins pulling on a nearby feature may be heading toward hypertrophy or keloid, and early injection or pressure treatment is more effective than late. MedlinePlus lists infection, bleeding, poor wound healing and recurrence of the scar among the recognized risks of revision, and all are easier to manage when reported early.

Before leaving the clinic on the day of surgery, make sure you have a direct number for the surgical team and know who covers evenings and weekends. Keeping that information to hand is the single most useful piece of aftercare planning.

Frequently asked questions

Are scar revisions worth it?

They are most worthwhile when the scar’s problem is mechanical: too wide, badly aligned, tethered or restricting movement, because surgery changes those features predictably. They are least reliable for keloids, where recurrence after excision alone is common. Worth also depends on accepting that the result is a better scar, not no scar, and that judging it fairly takes about a year.

How painful is scar revision surgery?

The procedure itself is usually done under local anesthesia and causes little pain beyond the initial numbing injection. Afterward, most people describe soreness and tightness rather than sharp pain, peaking in the first two or three days and easing over the following week. Pain that increases rather than settles, especially with redness or discharge, should be reported to the surgical team.

Will insurance pay for a scar revision?

It depends on the plan and on whether the scar causes a documented functional problem such as restricted movement, pain, recurrent breakdown or distortion of a feature. Revisions considered purely cosmetic are often not covered. Most insurers require pre-authorization and clinical notes or photographs from the surgeon, so ask the surgeon’s office what documentation your plan needs before scheduling.

What is the success rate of scar revision?

There is no single evidence-based success percentage, because studies measure different outcomes in different scar types, and no major guideline body publishes a pooled figure. What the evidence supports is that revision reliably improves wide, misaligned and contracted scars, while keloids carry a meaningful recurrence risk after surgery alone. Any clinic quoting one number is describing its own selected cases.

When is a scar mature enough for revision?

A scar is considered mature when it has stopped changing: its color has settled toward the surrounding skin, it is soft and flat, and it no longer itches or tightens. The NHS notes scars can take up to two years to settle, and many surgeons wait at least a year unless the scar is restricting movement or distorting a feature.

Is hypertrophic scar surgery different from keloid surgery?

Yes. Hypertrophic scars stay within the original wound edges and often flatten on their own, so surgery is reserved for ones that persist after a waiting period and non-surgical measures. Keloids spread beyond the wound and tend to recur after excision, so surgery for them is almost always paired with injections, pressure or other adjuncts to reduce the risk of regrowth.

Does scar revision for keloids work without surgery?

Often it is the preferred starting point. Corticosteroid injections into the keloid reduce inflammation and collagen production and can soften and flatten it over repeated sessions. Silicone sheeting, pressure devices and cryotherapy are also used, particularly for small keloids. Whether to begin with these, proceed to excision with adjuncts, or leave the keloid alone is a decision for a dermatologist or plastic surgeon.

Will the new scar be smaller than the old one?

Usually it will be narrower and flatter but not shorter. Removing a scar as an ellipse requires a length roughly three times the width excised so the skin closes flat, and techniques such as Z-plasty deliberately lengthen and redirect the scar to relieve tension. The aim is a scar that blends with skin lines and is harder to notice, not a shorter line.

Can people with dark skin have scar revision?

Yes, with additional planning. Brown and Black skin carries a higher likelihood of keloid formation and of pigment changes during healing, so surgeons ask closely about previous scars and often combine surgery with adjunct treatments and strict sun protection. Skin type is one factor among several, and many people with darker skin are suitable candidates after an individualized assessment.

How long before I can see the final result of scar revision?

Plan on about a year. The revised scar often looks redder and firmer between roughly six weeks and three months as new collagen builds, then gradually softens and fades. The NHS and MedlinePlus both describe final scar appearance as taking a year or longer to settle, which is why surgeons typically schedule a review around that point.

References

• MedlinePlus Medical Encyclopedia: Scar revision
• MedlinePlus Medical Encyclopedia: Keloids
• NHS: Scars

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.