---
title: "Fluid Retention in Legs and Ankles: 8 Ways to Switch On the Calf Pump That Drains Them"
description: Why your legs, ankles and feet swell in heat, on flights and after long days, and eight ways to switch on the calf pump that drains the fluid.
author: Dr Marina Nani (Editor-in-Chief)
date: 2026-11-12T17:00:00.029Z
updated: 2026-11-12T17:00:00.036Z
canonical: https://richhealthmagazine.com/article/fluid-retention-in-legs-and-ankles
image: https://cdn.nanimediahouse.com/pexels-4429101.webp
categories: Health, Fitness & Movement
content_type: Guide
publication: Rich Health Magazine
schema_type: Article
---

By six o'clock your shoes feel half a size smaller. Your socks leave a ridge around each ankle, and your legs feel heavy on the stairs. Your legs, ankles and feet are where fluid retention shows up first for most people, and they are also where you can shift it fastest, as long as you know what drains them.

Here is why swelling settles in your legs, ankles and feet, and the movement, nourishment and nervous system steps that drain it.

## Why Your Legs, Ankles and Feet Swell

When you stand or sit upright, gravity pulls blood down into the veins of your lower legs. The pressure inside those veins rises, and more fluid seeps out of your smallest blood vessels into the surrounding tissue. Your ankles and feet sit lowest, so they collect the most.

**Heat** makes it worse. In hot weather the blood vessels near your skin widen to release warmth, more fluid escapes through their walls, and gravity carries it down to your feet. Most people also move less in the heat, which slows the drainage further.

**Pregnancy** adds extra blood volume, hormones that relax the walls of your veins and a growing womb that presses on the large veins carrying blood up from your legs. Mild ankle swelling that builds through the day is common, especially in the last three months.

**Medicines** can play a part too. Some blood pressure tablets such as amlodipine, anti-inflammatory painkillers such as ibuprofen, steroids and the contraceptive pill all cause ankle swelling in some people. Never stop a prescribed medicine on your own, but ask your GP or pharmacist whether yours could be the cause.

## What the Calf Muscle Pump Does

Your heart pushes blood down to your feet easily. Getting it back up again, against gravity, is the job of your calf muscles.

The deep veins of your lower leg run through the middle of your calf muscles, and they have one-way valves inside them. Each time your calf tightens, it squeezes those veins and pushes blood upwards. When the muscle relaxes, the valves close to stop the blood falling back. The same squeeze moves lymph through the lymph vessels of your legs. Doctors often call your calves your second heart.

The pump only works when your ankle moves. When you sit at a desk or stand still in a queue, it stops, the pressure in your ankle veins stays high and fluid builds up. When you start walking, the pressure in your ankle veins falls sharply within a dozen or so steps. High heels hold your ankle in a fixed position and weaken each squeeze, so a flat or low, wide heel helps your calves do their work.

## Movement That Drains Your Legs

### Calf Raises and Ankle Pumps Every Half Hour

Set a reminder for every 30 to 45 minutes. At your desk, point your toes away from you and then pull them back towards you 20 times, then circle each ankle ten times in each direction. If you can stand, rise slowly onto your toes and lower your heels 15 times. Each movement squeezes your calf veins and empties them upwards.

### A Brisk Ten-Minute Walk After Meals

A short walk after lunch and dinner keeps your calf pump working at the times you are most likely to sit for a long stretch. Walk briskly, heel first and then toe, so your ankle moves through its full range. The same walk also softens the rise in blood sugar after a meal.

### Legs Up for Twenty Minutes

Raising your legs lets gravity work for you instead of against you. Lie on your back on the sofa, the bed or the floor and rest your calves on two or three firm cushions, so your heels sit higher than your heart. A pillow under your feet while you sit in a chair barely helps, as your ankles are still below your heart. Stay there for 15 to 20 minutes, two or three times a day while your legs are swollen. Lying on the floor with your legs resting up a wall works just as well. If you feel breathless lying flat, skip this step and speak to your GP.

### Swimming and Walking in Water

Water presses on your body, and the deeper the water, the harder it presses. When you stand or swim upright in a pool, the pressure is greatest at your ankles and least at your thighs, which squeezes fluid upwards in the same way as a support stocking. Cool water also narrows the blood vessels in your skin. Twenty minutes of swimming, or walking lengths in the shallow end, combines that pressure with constant work from your calves.

### Compression Socks, Fitted Properly

Graduated compression socks and stockings are tightest at the ankle and looser towards the knee, so they help push fluid upwards and stop it pooling. Ask a pharmacist to measure your ankle and calf, as the wrong size can dig in and make swelling worse. Light flight socks are useful on long journeys. Do not wear compression without speaking to your GP first if you have poor circulation in the arteries of your legs, for example calf pain when you walk that eases when you stop, if you have diabetes with numbness in your feet, or if the skin on your legs is fragile or broken.

## Food and Drink That Help Your Legs

### Less Salt, More Potassium

Your kidneys hold on to water to balance the salt you eat, so salty days show up as fuller ankles. UK guidance is no more than 6g of salt a day for adults, about one level teaspoon, and most of it is already in bread, cheese, cured meats, sauces and ready meals. Potassium helps your kidneys pass sodium out in your urine. Good sources are potatoes eaten with their skins, beans, lentils, spinach, tomatoes, bananas, dried apricots and plain yoghurt. If you have kidney disease or take medicines that raise potassium levels, check with your GP before you eat much more of it.

### Enough Water Through the Day

Cutting back on water does not reduce swelling. When you are short of water, your brain releases a hormone that tells your kidneys to hold on to what you already have. Drink steadily through the day, and more in hot weather, so your urine stays pale yellow. Our guide to [the best times to drink water](https://richhealthmagazine.com/article/optimal-water-intake-the-most-effective-times-to-hydrate-your-body) helps you spread it out.

## Calming Your Nervous System to Help Drainage

### Slow Breathing With Your Legs Raised

Turn your legs-up time into a breathing practice. Rest one hand on your stomach, breathe in through your nose for a count of four so your stomach rises, and breathe out for a count of six. Each slow in-breath pulls your diaphragm down and lowers the pressure in your chest, which draws blood and lymph up from your belly and legs towards your heart. Slow breathing also moves your nervous system out of its stress setting, and lower stress hormones mean your kidneys hold on to less salt. Ten slow breaths are enough to start. For more techniques, read our guide to [calming your nervous system in minutes](https://richhealthmagazine.com/article/how-to-calm-your-nervous-system-7-fast-techniques).

## A Plan for Long Flights and Car Journeys

Sitting still for hours with your knees bent is the hardest test for your calf pump, and journeys of four hours or more also raise your risk of a blood clot.

- Book an aisle seat so you can get up easily.
- Wear light flight socks if they are safe for you.
- Do ankle pumps and circles every 30 minutes, and walk the aisle every hour or two.
- Drink water regularly and go easy on alcohol and salty snacks.
- Loosen your shoes rather than taking them off completely, so you can get them back on when you land.
- On a long drive, stop every two hours and walk for a few minutes.

## When Swollen Legs Need a Doctor

Swelling in both legs that goes down overnight and responds to the steps above is usually harmless. Ask for an urgent GP appointment or call NHS 111 if one leg swells without an injury, especially with pain, warmth or redness in the calf, as that can be a blood clot. Call 999 if leg swelling comes with breathlessness, chest pain or coughing up blood. Our guide to [the signs of fluid retention](https://richhealthmagazine.com/article/signs-of-fluid-retention) sets out the other warning signs in full.

If you are pregnant, call your midwife or NHS 111 straight away if swelling in your face, hands or feet comes on suddenly, or if you also have a bad headache, problems with your vision or pain just below your ribs. These can be signs of pre-eclampsia, which needs checking the same day.

Start with the smallest step tonight: ten slow calf raises while the kettle boils and 20 minutes with your heels above your heart. Keep it up for a week, and your socks will show you the difference before the scales do.

## In Case You Were Wondering

**Q: Why do my feet swell in hot weather?**
In hot weather the blood vessels near the skin widen to help the body lose heat. Wider vessels let more fluid leak into the surrounding tissue, and gravity pulls it down into the feet and ankles. Sitting or standing still, salty food and not drinking enough make heat swelling worse. Keeping cool, walking, raising the legs above heart level and drinking water usually help. Swelling in one leg only, or swelling with pain, redness or breathlessness, needs medical advice.

**Q: What is the calf muscle pump?**
The calf muscle pump is the way the muscles of the lower leg push blood and fluid back up towards the heart. The deep veins of the calf run through the muscle and contain one-way valves. When the calf muscles tighten during walking or ankle movement, they squeeze the veins and push blood upwards, and the valves stop it flowing back down. When a person sits or stands still for long periods, the pump stops working and fluid can build up in the ankles and feet.

**Q: How long should you elevate your legs to reduce swelling?**
Raising the legs for 15 to 20 minutes at a time, two or three times a day, usually helps reduce swelling in the ankles and feet. The legs need to be higher than the heart, so the most effective position is lying down with the calves supported on cushions or resting up a wall. Resting the feet on a stool while sitting helps far less. People who feel breathless when lying flat should speak to a GP before trying this.

**Q: Why do ankles swell during pregnancy?**
During pregnancy the body carries extra blood and fluid, hormones relax the walls of the veins, and the growing womb presses on the large veins that carry blood up from the legs. Together these make fluid collect in the ankles and feet, especially later in the day and in the last three months. Mild swelling is common. Sudden swelling of the face, hands or feet, or swelling with a severe headache, vision problems or pain below the ribs, can be a sign of pre-eclampsia and needs urgent advice from a midwife or NHS 111.

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*This article is for general information only and is not medical advice. It does not replace a diagnosis or treatment from your GP or another qualified health professional. Speak to your GP or pharmacist before you change your diet, exercise routine or medicines, especially if you are pregnant, have a long-term health condition or take regular medication. If you have sudden, severe or one-sided swelling, or swelling with shortness of breath or chest pain, call 999.*