There is a single number that often decides whether you go home in compression stockings:

90 minutes.

Spend that long or more under general anaesthetic, and you cross a recognised threshold for blood clot risk, which is why surgical teams treat time under anaesthesia, not just the operation, as a main reason to put you in compression. The stockings are answering a danger, the anaesthetic and the stillness around it created, and understanding that changes how you think about the whole timeline.

This guide explains how long to wear them, why the anaesthetic itself raises your clot risk, how the day-and-night pattern shifts as you recover, and the warning signs that need a doctor.

Main Squeeze Compression Socks are an MHRA-registered medical device, so the guidance is grounded in how compression behaves on a recovering body, honest about both benefits and limits.

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What the Anaesthetic Does to Your Legs

A general anaesthetic does more than send you to sleep. It removes the very thing that normally keeps blood moving in your legs. Awake and upright, your calf muscles squeeze with every step and push blood back up towards the heart. Under anaesthetic, you lie completely still, often for the length of the operation and for hours afterwards, so that the natural pump goes quiet and blood flow in the legs slows right down.

That stillness is the danger. Slowed blood flow in the deep leg veins makes it easier for a clot to form, a deep vein thrombosis, and the serious risk is a fragment breaking away and travelling to the lungs. UK practice puts a clear marker on it: being under general anaesthetic for 90 minutes or more is one of the recognised triggers for assessing whether you need compression. The longer the surgery and anaesthetic last, the more time your blood spends sitting still, and the more compression earns its place. Our guide on compression and DVT explains the mechanism.

How Long, Phase by Phase?

After a procedure under general anaesthetic, most people wear compression socks for two to six weeks, with the exact length set by the type of surgery, your personal clot risk, and how quickly you get moving again. The anaesthetic raises the risk; the operation and your recovery shape how long that risk lasts. That is why the same range covers everything from a short day-case procedure to a major operation, with your own figure somewhere inside it. The need tapers as your mobility returns rather than stopping on a fixed date.

Your clot risk peaks while you are least mobile, which is why the round-the-clock phase usually covers the early days in hospital and sometimes the first weeks at home. As you start walking properly and your calf muscles take back the pumping job, most people move to daytime-only wear, since lying flat at night does that work for you. Even after a day-case operation where you go home the same day, you may still be sent home in stockings if you will be sitting or resting for a stretch.

What Moves Your Figure Within the Range?

Three factors mostly decide where you land between two and six weeks.

The first is the one specific to this question:

The length of the anaesthetic and the operation.

A brief procedure that kept you under for well below the 90-minute mark, with a quick return to your feet, sits at the shorter end. A long operation under prolonged anaesthetic means more hours of stillness and a higher clot risk, which tends to attract longer compression. The type of surgery matters alongside this, since a major abdominal or orthopaedic procedure keeps you immobile longer than a minor one.

The second is your medical history. A previous DVT, a clotting disorder, hormone treatment, being over 60, extra weight, or smoking can all extend the time as a precaution. Reduced mobility after the operation is its own risk factor: needing bed rest, struggling to walk without help, or spending most of the day in a chair all keep blood flow slow and the risk high for longer.

The third is the practical dial, mobility, with swelling pulling the other way. The sooner you are walking properly, the sooner your own circulation takes over, and compression can taper. But if your legs are still puffy as the weeks pass, that is usually a reason to keep going with daytime wear, since lingering post-surgical swelling can overlap with the fluid pooling of venous insufficiency.

Should You Wear Compression Socks Day and Night, or Just Day?

In the first phase, often day and night; later, usually daytime only. While you are in hospital and through the early days when your clot risk peaks, surgeons commonly ask you to wear stockings around the clock, removing them only to wash, because in those first immobile days after an anaesthetic, the job of moving blood does not pause overnight. The pattern flips once you are up and walking, because lying flat removes the gravity that pulls fluid into the legs. There is also a practical hazard once supervision ends:

A sock can twist or bunch as you sleep and form a tight band that quietly restricts circulation. Follow the specific instructions your surgeon gives you, and do not stretch or cut it short on your own. Our guide on getting the timing right explains the daytime routine.

Stopping Safely?

Stopping works best as a gradual taper rather than a hard switch on a set date. When your surgeon clears you, wear them through the day for a few more days, then reduce, watching how your legs respond at each step. Keep an eye on swelling as you cut back, and if your legs or feet puff up again, put the socks back on and mention it to your doctor.

One rule overrides comfort:

Never stop while you are still largely confined to bed or barely mobile, because that is exactly when clot risk is highest. The socks come off when your body has taken back the work of moving blood, not when you feel ready to be rid of them. Stopping too early after an anaesthetic can undo the protection during the very window it matters most.

The Risk of Wearing Them Too Long

Compression has a job, and once it is finished, keeping the socks on past usefulness causes harm. Prolonged or ill-fitting wear can bring skin irritation, itching, redness, and dryness, and in worst cases, blisters, sores, or pressure damage. Over-tight compression worn too long can restrict blood flow rather than support it, producing numbness, tingling, or a burning feeling. Resting your legs at night and stopping when your surgeon says the risk has passed keeps compression on the helpful side of that line.

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When to call?

Compression lowers your clot risk; it does not remove it. Contact your surgeon or seek urgent advice if you notice new or worsening swelling in one leg that does not match the other, calf pain or tenderness that builds rather than eases, or skin that feels warm, red, or unusually tight. Breathlessness or chest pain after an operation is a medical emergency and needs immediate help, because it can mean a clot has reached the lungs. A quick check always beats ignoring a symptom that turns out to matter.

Because so much here turns on details only your surgical team knows, how long you were actually under, what your personal risk looks like, settle those details before you are discharged. Three things are worth getting straight: how many weeks they expect you to wear them, whether that means day and night or daytime only, and what specific signs should make you stop.

Get the answers in writing, and the 90-minute threshold that started all of this becomes just one input into a plan you actually understand. A comfortable, MHRA-registered pair sized to your morning leg measurements is what makes following that plan painless through the longer recovery days.