What is Oedema? A Podiatrist Explains the Causes and Treatment

A podiatrist explains why feet and ankles swell, when swelling needs checking, and how to choose shoes for a foot that changes size through the day.

Alannah Andrews

Senior Podiatrist, Sunshine Coast Health Services, Buderim QLD

Dip. App. Sc (Pod), B. App Sc. (Pod), Grad Dip (Geront), Grad Dip (Bus), M.Bus (Mgmt). More than 35 years in clinical podiatry.

Read Alannah's full bio

What is oedema?

Swollen feet and ankles are something I see regularly in clinical practice, particularly in older people, those with reduced mobility and people living with chronic health conditions.

For some, the swelling is relatively mild and only becomes noticeable towards the end of the day. For others, their feet can change considerably in size and shape, making shoes uncomfortable or difficult to put on.

I often have patients tell me that their shoes fit perfectly well in the morning, but by the afternoon they're struggling to get them off.

The medical term for this swelling is oedema. It's important to understand that oedema is a symptom rather than a diagnosis in itself. While appropriate footwear can make a considerable difference to comfort and mobility, we also need to understand why the swelling is occurring.

Understanding why our feet and ankles swell

When I'm explaining oedema to patients, I often start by talking about three important systems in our body that work together to maintain circulation and fluid balance.

• The first is the arterial system, which carries blood away from the heart, delivering oxygen and nutrients to the tissues throughout our body.
• The second is the venous system, which returns blood from our extremities towards the heart. From there, it travels to the lungs to collect more oxygen before being pumped around the body again.
• The third is the lymphatic system. This is sometimes overlooked, but it has a very important job. As blood circulates through our tissues, some fluid naturally moves out of the tiny blood vessels into the surrounding tissues. The lymphatic system collects excess fluid, along with proteins and other substances, and returns it to the bloodstream.

These systems work together to maintain a healthy balance of fluid within our tissues.

When that balance is disrupted, fluid can begin to accumulate, particularly in the feet, ankles and lower legs. This is what we call oedema.

Gravity also plays a part, which is why swelling often becomes more noticeable after spending long periods sitting or standing.

What causes oedema?

There are many possible causes of swollen feet and ankles.

Some of the more common ones include:

• Venous insufficiency: When the veins and their valves have difficulty returning blood efficiently from the legs.
• Reduced mobility: Sitting or standing for extended periods reduces the assistance provided by our calf muscles in returning blood towards the heart.
• Lymphoedema: When the lymphatic system cannot adequately drain fluid from the tissues.
• Medications: Some medications, including certain blood pressure medications, can contribute to swelling.
• Injury or inflammation: Swelling may occur following an injury, surgery or inflammatory condition.
• Heart, kidney or liver conditions: These can affect the body's fluid balance and contribute to oedema.

Occasionally, swelling can indicate something more serious, such as a blood clot or infection.

One thing I always encourage patients to remember is that persistent swelling shouldn't simply be dismissed as a normal part of getting older.

Does it matter if one or both feet are swollen?

Yes, it can.

Swelling affecting both feet and ankles is commonly associated with prolonged sitting or standing, venous insufficiency, certain medications and some general medical conditions.

Swelling that develops suddenly in one leg, particularly if accompanied by pain, warmth or redness, needs prompt medical assessment because it may indicate a deep vein thrombosis (DVT) or another significant problem.

If swelling occurs with sudden shortness of breath, chest pain or collapse, seek emergency medical assistance immediately.

New, unexplained or worsening swelling should always be discussed with your GP or another appropriate health professional.

You don't have to put up with poorly fitting, uncomfortable shoes

One thing I regularly notice in clinical practice is that many people with swollen feet have simply given up trying to find shoes that fit.

Some resort to wearing hospital-style non-slip socks around the house, while others wear oversized slippers or shoes that are several sizes too big. Often, they tell me that these are the only things they can comfortably get their feet into.

The problem is that these options don't always provide the protection, support or stability needed for safe walking, particularly for older people or those who already have balance difficulties.

What many people don't realise is that we are fortunate in Australia to have access to footwear specifically designed for people with swollen or difficult-to-fit feet. (Comfort Co note: these shoes are available in New Zealand too.)

These shoes are quite different from simply buying a larger size. Many have generous openings, additional width and depth, soft protective uppers and adjustable fastenings that allow the fit to be altered as swelling changes.

I often find that patients are pleasantly surprised to discover that they can wear a properly fitted pair of shoes again, rather than relying on slippers or socks.

What should you look for when choosing footwear?

When assessing footwear for someone with oedema, there are several features I consider important.

• Adjustability: Adjustable straps or fastenings allow the shoe to accommodate changes in foot volume throughout the day. Multiple points of adjustment can be especially helpful because swelling doesn't always occur evenly throughout the foot.
• Adequate width and depth: A swollen foot doesn't necessarily just become wider. Swelling frequently occurs across the top of the foot and around the toes, so additional depth can be just as important as width.
• A generous opening: A shoe that opens widely makes it much easier to get a swollen foot into it. This is particularly useful for people who also have arthritis, reduced hand strength or difficulty bending to put their shoes on.
• A secure fastening and stable sole: Although we need to accommodate swelling, the shoe still needs to fit securely. A shoe that is too loose can allow excessive movement of the foot, affecting walking stability and increasing friction.
• Soft, protective materials: Swollen skin can be more vulnerable to pressure and irritation. Soft uppers, adequate internal space and minimal seams can help reduce these problems.
• Removable footbeds: These can provide additional flexibility by allowing extra depth or space for prescribed orthoses where appropriate.

I often explain to patients that buying a bigger shoe isn't necessarily the answer. We need to find something that gives their feet enough room when they're swollen, but doesn't become too loose when the swelling settles.

Simple things you can do at home to help manage oedema

Once the underlying cause of swelling has been assessed, there are several practical things that may help, particularly when oedema is associated with prolonged sitting, standing or reduced mobility.

Give your legs a break from gravity

One of the simplest strategies is to elevate your legs during the day.

When we sit or stand for long periods, gravity encourages fluid to accumulate in the lower limbs. Elevating the legs can help fluid return towards the body.

If appropriate for your medical condition, try lying down with your legs comfortably supported above heart level for around 20–30 minutes. Lunchtime or an afternoon rest can be a convenient opportunity.

Simply resting your feet on a footstool may feel comfortable, but elevating them above heart level is generally more effective.

Make sure the position is comfortable, and avoid placing pressure behind the knees. If lying flat causes breathlessness or discomfort, stop and seek medical advice.

Keep your ankles moving

Our calf muscles act as a natural pump, helping return blood from the lower legs towards the heart.

When we're walking, these muscles work regularly. When we sit for long periods, that pumping action is reduced.

Try moving your ankles up and down 15–20 times every hour while sitting. Gentle ankle circles or alternating between lifting your heels and toes can also help.

Take regular short walks

Walking activates the calf muscle pump and can help reduce the effects of prolonged sitting.

Even a few minutes walking around the house or garden can be beneficial, provided it's safe for you to do so.

Look after your skin

Swollen skin can become stretched, dry and more vulnerable to injury.

Keep your feet and lower legs clean and appropriately moisturised. Check regularly for redness, blisters, cracks or broken skin.

This is particularly important for people with diabetes or peripheral neuropathy, who may not always feel pressure or irritation.

Consider whether compression therapy is appropriate

Compression stockings can be very effective for some types of oedema, particularly swelling associated with venous insufficiency.

However, compression isn't suitable for everyone and should be recommended following appropriate assessment, including consideration of arterial circulation and other medical conditions.

People with persistent lymphoedema may also benefit from assessment by a suitably qualified lymphoedema practitioner.

Be mindful of salt intake

Excess dietary sodium can contribute to fluid retention in some people.

Reducing heavily processed and high-salt foods may help, particularly when recommended as part of managing blood pressure or certain medical conditions.

However, dietary changes alone won't resolve every cause of oedema.

Don't forget about your socks

Socks can sometimes be just as troublesome as shoes.

A tight elastic cuff can leave a deep indentation around a swollen ankle or lower leg. Look for socks that fit comfortably without constricting the skin or bunching inside your shoes.

Non-restrictive socks (often called Diabetic socks) have a more relaxed band and may be helpful for some people, but these should not be confused with medical compression stockings.

When should you have your shoes fitted?

If your feet tend to swell throughout the day, it can be helpful to try shoes when some of your usual swelling is present, rather than only first thing in the morning. I generally suggest going later in the afternoon.

However, the shoes must still fit securely when the swelling reduces.

Always try both shoes, as swelling isn't necessarily the same in each foot.

And remember, the number on the shoe box is only a guide. How the shoe actually fits your foot is far more important.

Check your feet when you take your shoes off

One final piece of advice I regularly give patients is to take a moment to look at their feet when they remove their shoes.

Check for persistent redness, pressure marks, blisters, rubbing or broken skin.

If you have reduced sensation in your feet, this becomes particularly important because you may not feel the discomfort that would normally warn you that your footwear is causing damage.

A final thought

Oedema can make finding comfortable footwear frustrating, particularly when your feet change size throughout the day.

But the answer isn't necessarily to buy a bigger shoe.

Look for footwear that can adjust to changes in foot volume while still providing adequate protection, comfort and stability.

And remember that while suitable footwear can help accommodate swelling, it doesn't explain why the swelling is occurring.

If your oedema is new, unexplained or worsening, have it assessed by an appropriate health professional.

With the underlying cause properly investigated and managed, a few practical strategies and carefully selected footwear can make a real difference to everyday comfort and mobility.

Alannah Andrews
Senior Podiatrist
Sunshine Coast Health Services
Buderim, Queensland

This article provides general educational information and does not replace individual medical assessment or advice.

The Comfort Co Solutions

The line to hold onto from Alannah's guide: the answer isn't a bigger shoe, it's a shoe that adjusts. The good news is The Comfort Co has you covered! The styles below are matched to the job they do best. None of them treats the swelling itself. They are there to keep you comfortable, protected and steady on your feet while the cause is managed.

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About these picks

The products below are suggestions from The Comfort Co team, not Alannah's clinical recommendations. Where Alannah recommends a style herself, we've quoted her directly. For advice on managing your oedema, book in with a podiatrist or your GP.

"I have found the Anodyne Wrap shoe (No. 84 for men, No. 85 for women) and the Revere range of adjustable sandals to be particularly useful for these clients. Their ability to accommodate fluctuations in foot volume is a significant advantage."

"From a clinical perspective, having footwear that can adapt to the foot, rather than expecting the foot to conform to a fixed shoe, can help maintain comfort and reduce unnecessary pressure and irritation."

Alannah Andrews, Senior Podiatrist, Sunshine Coast Health Services

Most adjustable sandal

Revere Miami Adjustable Sandal

Lets you change the fit as swelling changes through the day.

• Three points of adjustment
• Strap extenders add length where the swelling sits
• Medium and Wide widths
• Heads up: open toes give less protection if feeling in your feet is reduced

Shop now

Men's adjustable sandal

Revere Montana 2 Back Strap Sandal

Full adjustment across the forefoot, where swelling often builds.

• Hook-and-loop straps across the whole forefoot
• Matching strap extensions included
• Removable footbed with extra depth for orthoses
• Slip-resistant outsole

Shop now

The wrap-style shoe Alannah recommends

Anodyne Sport Double Depth Stretch

A closed-in shoe with room on top of the foot as well as across it.

• Stretch fabric upper
• Hook-and-loop closures on both sides
• Double depth and a wide toe box
• Insole lifts out for prescribed orthoses

Women's No. 85Men's No. 84

Dressier double depth

Anodyne Casual Double Depth Stretch

The same extra room in a shoe that looks less sporty.

• Stretch upper with the look of leather
• Double depth and a wide toe box
• Removable insole for orthoses

Women's No. 81Men's No. 88

Easiest to get on

Anodyne No. 77 v2 Double Depth Sport Walker with Heel Assist

Built for anyone with arthritis, weak hands or trouble bending.

• Step-in heel assist
• Double depth
• Certified slip-resistant outsole

Shop now

For regular short walks

Vitasole Walker Mesh III

Walking puts your calf muscles to work, and this is a cushioned, supportive option for regular short walks. How well it suits you still depends on your foot shape, swelling and mobility.

• Meta-rocker sole helps you roll through each step
• VX Technology EVA cushioning
• Memory-foam footbed lifts out for your own orthosis
• Medium and wide fittings

Shop now

Everyday sock

OS1st WP4+ Wide Wellness Performance Sock

A relaxed, non-restrictive sock.

• Extra room
• Seamless toe
• Non-binding top that won't dig into a swollen ankle

Shop now

Only if compression is recommended

OS1st FS4+ Compression Bracing Socks

IMPORTANT NOTE* ONLY for people whose podiatrist or GP has advised compression.

• Compression bracing sock, 20 to 30 mmHg

Shop now

Heads up

Not every compression sock suits oedema. This is a bracing sock, not a graduated compression stocking designed for managing lower-limb oedema. Check with your podiatrist or GP whether it suits your condition, as compression needs an assessment of your circulation first.

Instead of hospital socks

Scholl Easyfit Slipper

Secure home wear in place of non-slip socks or oversized slippers.

• Adjusts at two points
• Removable footbed
• Rubber outsole with grip

Women'sMen's

For shoes you already own

Realign Stretch Laces

A small fix if bending down to tie a bow is a struggle.

• Turns most lace-ups into slip-ons
• Gives a little as your foot fills out

Shop now

Comfort Co Pro Tip

Treat the removable footbed as a fit tool, not just a place for orthotics. In many Comfort Co styles, lifting the footbed or spacer out buys extra depth on a swollen day. Put it back when your feet settle if the shoe feels roomy. It's a handy top-up, not a substitute for straps you can loosen as swelling changes. Want to try before you buy? Visit the Comfort Co showroom in the afternoon and bring the socks you usually wear.

Keep Reading

The Comfort Edit

What is an Adjustable Shoe?

The Comfort Edit

What is a Rocker Sole?

The Comfort Edit

The Best Wide-Fitting Shoes for Women

Shop Revere sandals Shop Anodyne shoes

Quick questions

What causes swollen feet and ankles?

Swollen feet and ankles happen when fluid builds up in the tissues. Common causes include long periods of sitting or standing, venous insufficiency, lymphoedema, some medications, injury or inflammation, and heart, kidney or liver conditions. Swelling is a symptom, so the cause should be checked by your GP or another health professional.

When is a swollen foot or ankle an emergency?

Swelling that comes on suddenly in one leg, especially with pain, warmth or redness, needs prompt medical assessment because it may be a deep vein thrombosis. If swelling comes with sudden shortness of breath, chest pain or collapse, call 111 immediately.

What shoes are best for swollen feet?

Look for adjustable straps or fastenings, extra width and depth, a generous opening, a secure fit with a stable sole, soft uppers with minimal seams, and a removable footbed. Adjustable sandals and double-depth shoes with hook-and-loop fastenings are good starting points. A stretch upper is great for accommodating mild swelling, but once swelling builds through the day, you'll want a shoe you can loosen as well.

Should I buy a bigger shoe size if my feet swell?

Usually not. A shoe that fits a swollen foot can be too loose once the swelling settles, which lets the foot move around, affects stability and increases rubbing. An adjustable shoe that can be let out and tightened again is the better choice.

Do compression socks help swollen ankles?

Compression can be very effective for some types of oedema, particularly swelling linked to venous insufficiency. It isn't suitable for everyone, so it should only be used after an assessment that includes your arterial circulation. Non-restrictive socks are different: they have a relaxed top but do not apply compression.

What time of day should I buy shoes if my feet swell?

Try shoes later in the afternoon, when some of your usual swelling is present, and always try both shoes. The shoe still needs to feel secure when the swelling goes down, so adjustable styles make this much easier.

Alannah sees patients at Sunshine Coast Health Services in Buderim, Queensland. If you're ever in the area, you can book a podiatry appointment with her. Everywhere else, a local podiatrist is the right next step.