The August Ankle Swell: Heat & Travel Tips to Reduce Summer Leg Swelling

August in the Northern Hemisphere: the sky is blue, the sun is shining, the temperatures rise. For sun-lovers, this is the best time of the year. But for many people, the summer weather means swollen ankles and “heavy” legs – which can also be painful. People with varicose veins also suffer more discomfort in summer. But why? And what is the connection between heat and swollen ankles? In this article, we look into the numerous causes as well as the things that you can do to ease the problems.

“August ankle swell” is often the result of two converging factors: heat-induced fluid redistribution and travel-related circulatory stagnation. Sounds complicated, but it is not – and understanding how these factors impact both the vascular and lymphatic systems can help you take the necessary action during the summer months.

Fluid redistribution (vascular system)
At high temperatures, the blood vessels are dilated by the body so that excess heat can be released through the skin. Whilst this has a cooling effect, it also affects vein function, including slackening the vessel walls and increasing their permeability. Fluid then escapes from the vessels into the tissue, which in turn leads to water retention (oedema). Gravity plays a role here, meaning that the fluid often travels downwards into the legs and feet, thereby causing swelling, tension and pain. If heat exposure is prolonged, review our quick primer on sunstroke symptoms so you can spot warning signs early.

Circulatory stagnation (lymphatic system)
In hot weather, we tend to reduce our movement: we avoid going for walks or exercising, preferring to sit around and not sweat too much. Also, summertime is holiday time, and we often spend hours sitting practically still on a plane. Lack of movement, however, means that the muscle-venous pump, which helps to move blood from the legs up to the heart, does not work sufficiently. Long journeys often mean that we have to remain seated, almost immobile, for many hours at a time – this can result in deep-vein thrombosis, a serious vascular condition often preceded by leg and ankle swelling.

A further factor that additionally exacerbates the situation caused by fluid redistribution and reduced movement is a lack of fluids. In hot temperatures, the body loses fluid through sweating. This fluid needs to be replaced, and if we do not drink enough, the blood thickens, which makes it even harder for blood to return to the heart. The viscosity of the blood increases and the flow rate decreases, increasing the risk of thrombosis. For practical ways to balance intake on hot days, see what dehydration really is and how to fix it.

The impact of heat on circulation
Heat increases the overall blood flow to the periphery. But it also initiates sweating, which leads to a loss of electrolytes such as sodium, a key mineral for fluid balance. Depleted electrolytes can cause fluid to move more readily from the bloodstream into tissues (especially during vasodilation). If you’re unsure whether your symptoms point to mineral imbalance, skim our checklist of electrolyte imbalance warning signs.

Who is at risk?
Almost anybody can experience summer swelling, but certain groups of people are more vulnerable:

• Pregnant women, as a result of heightened circulatory volume and pressure on pelvic veins.
• Older adults, whose vascular and lymphatic systems are generally less resilient.
• Individuals with pre-existing venous insufficiency, varicose veins, or lymphoedema.
• People with very low physical activity, in particular during travel.
• People with cardiovascular conditions or on certain medications, such as calcium channel blockers (CCBs) prescribed for high blood pressure or angina.

How to combat “August ankle swell”
There are a number of things you can do in order to help you cope with (and prevent) ankle swelling caused by heat and travel. We’ve divided these into “Vascular tactics” and “Lymphatic tactics”.

Vascular tactics

• Hydrate with electrolytes, not just water: Aim for regular sips and balance fluids with electrolytes. Water alone can dilute sodium levels if you overdo it. Low-sugar electrolyte drinks (or tablets) help maintain fluid balance without excessive sugar. If swelling hangs around with puffiness elsewhere, review water retention basics.
• Compression stockings: Graduated compression stockings (20–30 mmHg for general use; 30–40 mmHg for greater oedema) support venous return. Put them on before swelling starts (e.g., prior to your flight) and keep them on during long journeys.
• Leg elevation and movement: Whilst sitting comfortably, raise your legs up to heart level for 15–20 minutes. Repeat this 2–3 times daily to assist fluid return. During flights or train journeys, stand up and walk along the aisle every 60–90 minutes, if possible. When seated, perform “leg raises” and “foot circles” to maintain calf-muscle pump activity. For safe summer activity ideas, check tips for running in heat.
• Air-activated cooling wraps or bandages: These provide cooling and mild compression simultaneously and are useful in cases of acute, heat-induced swelling. And when UV is fierce, these Spanish summer sun tips help you avoid overexposure that can worsen symptoms.

Lymphatic tactics

• Manual lymphatic drainage (MLD): A gentle massage technique that stimulates lymphatic flow. Increasing lymphatic flow can reduce swelling and the discomfort associated with it. Learn the fundamentals in our overview of lymphatic drainage.
• Active lymphatic movement: Gentle walking, cycling or ankle-pumping (lifting toes while seated) every hour increases both venous and lymphatic flow. Need a simple routine? Start with walking daily for better health.
• Dry brushing or gentle stimulation: While evidence is limited, brushing the skin of the legs (from the foot towards the body) can activate superficial lymphatic flow, especially when combined with light oils and done before leg elevation.
• Short-stretch bandaging: Self-administered lymphatic compression bandaging (using cohesive, short-stretch bandages) creates low resting pressure and higher working pressure during movement, which can assist lymph return. Learn technique from a professional first.

Your heat-and-travel routine (copy/paste checklist)

• Wake-up: 500 ml water + electrolytes; 5–10 minutes feet-up; compression socks on if a travel day.
• Morning movement: 10–15 minutes of gentle calf raises, ankle circles and a short walk (indoors if necessary).
• Midday: Prioritise shade or air-con breaks; rehydrate (electrolytes if sweating); avoid very heavy meals.
• Afternoon cool-down: Swim if possible (hydrostatic pressure helps fluid return) — see why swimming helps — or do a cool shower and elevate legs.
• Evening: Light dinner with potassium-rich foods (banana, avocado, tomato, leafy greens) to balance fluids; brief walk after eating.

Travel-day tactics: in transit
On planes, trains and in cars:

• Choose aisle seating if possible so it’s easier to stand and move.
• Wear compression stockings on long journeys and put them on before boarding.
• Wear comfortable, loose-fitting footwear (feet often expand in heat and during flights).
• Elevate your legs when you can, even briefly, and avoid crossing your legs for long periods.
• Do calf raises while waiting in queues and practice foot circles and ankle pumps when seated.
• Walk the aisle every 60–90 minutes on flights and trains; plan regular rest stops when driving. Travelling with kids? These flying-with-kids tips help everyone keep moving.
• Hydrate steadily; choose electrolyte drinks or tablets dissolved in water. If you’re sensitive to motion, review motion-sickness prevention to keep nausea from limiting your movement.

At your destination:

• Start moderate exercise as soon as you can (a short walk after check-in works well).
• Go swimming to activate deep lymphatics and enjoy gentle, sustained movement with natural compression from water.
• Book MLD or have a gentle self-massage session if swelling and discomfort persist.
• Favour lighter meals; include potassium-rich foods (banana, avocado, leafy greens) and adequate protein for tissue repair.
• Use cooling wraps if heat and swelling are intense, especially after long hot days on your feet.
• Limit alcohol and caffeine if swelling is problematic, as both can worsen dehydration in heat.
• Avoid tight footwear and prolonged static postures; set a 45–60-minute “move” reminder.

Myths vs facts

• “Just drink loads of water.” Fact: Over-diluting electrolytes can worsen swelling for some people. Balance plain water with electrolytes when sweating. If cramps or dizziness strike, revisit the electrolyte signs.
• “Compression is only for older people.” Fact: Anyone on a long flight, pregnant travellers, those with a history of swelling, or athletes after events can benefit.
• “If one leg swells, it’s just the heat.” Fact: Unilateral swelling, especially with pain, warmth or redness, is a red flag. Seek medical evaluation promptly.

When to consult a doctor

• Unilateral, rapid swelling, in particular when accompanied by pain and warmth in the leg.
• Redness, severe tenderness, or systemic symptoms such as fever.
• Persistent swelling lasting more than a week after the journey, or worsening despite rest and self-care.
• Signs of kidney, heart, or liver issues (e.g., breathlessness, chest pain, dark urine).
• New swelling after starting a medication (e.g., some blood-pressure medicines) — ask your clinician if this could be a side effect. If you live here, here’s how to register with a doctor in Spain.

Simple packing list for “low-swelling” summer travel

• Graduated compression stockings (20–30 mmHg; higher only if advised).
• Electrolyte tablets or powders you can dissolve in water.
• Lightweight cooling wrap or reusable gel pack.
• Short-stretch cohesive bandage (only if trained in safe application).
• Comfortable, adjustable footwear with room for mild swelling.
• Refillable water bottle and a small timer/reminder app set to move every 60 minutes.

Diet pointers that actually help

• Focus on potassium-rich foods (bananas, avocados, tomatoes, leafy greens) alongside adequate water and electrolytes to help balance fluids.
• Include lean proteins and colourful vegetables to support vessel integrity and recovery, especially after long travel days.
• Keep restaurant salt in check on travel days if you’re not sweating much; if you are sweating heavily, don’t eliminate salt entirely unless advised to do so by your doctor.

Bottom line
August ankle swell can be uncomfortable and painful, and if symptoms persist, medical advice should be sought promptly. However, by taking a few precautions and maintaining movement and hydration, it can be easily combatted and managed, enabling you to enjoy the summer temperatures without heavy-leg misery.

Need fast access to care in Spain?

If you’re living in Spain or planning a move, private cover helps you see vascular and cardiology specialists quickly and arrange tests without long queues. Explore our expat health insurance in Spain. A popular everyday option is Sanitas Mas Salud Family. If you need help choosing the best private health insurance in Spain for your situation, we can guide you — get a quick quote and personal support today.