Fluid retention happens when your body holds onto more water than it should, usually in the spaces between your cells. The fix depends on what’s driving it, but for most people, the combination of dietary changes, movement, and simple physical strategies can make a noticeable difference within days. Here’s what actually works and why.
Why Your Body Holds Onto Extra Fluid
Your capillaries, the tiniest blood vessels, constantly filter fluid into surrounding tissues. Normally, your lymphatic system drains that fluid back into circulation. Swelling starts when filtration outpaces drainage. Four things tip that balance: high pressure inside the capillaries (from gravity, heart problems, or blocked veins), low protein levels in the blood (which reduce the pulling force that keeps fluid inside vessels), leaky capillaries from inflammation or injury, and blocked lymphatic drainage.
For most people searching for a fix, the culprit is one of the simpler triggers: too much sodium, prolonged sitting or standing, hormonal shifts during the menstrual cycle, or not drinking enough water. These are all reversible without medical treatment.
Cut Sodium, Increase Potassium
Sodium is the single biggest dietary driver of fluid retention. It pulls water into the spaces outside your cells, expanding your fluid volume. The World Health Organization recommends staying under 2,000 mg of sodium per day, which is just under a teaspoon of table salt. Most people consume well over that, largely from processed and restaurant foods rather than from a salt shaker.
Potassium works in the opposite direction. It helps your kidneys excrete sodium and balances the fluid pressure inside and outside your cells. Eating more potassium-rich foods (bananas, sweet potatoes, spinach, avocados, beans) while cutting back on sodium shifts the ratio in a way that encourages your kidneys to release excess water. You don’t need to track exact numbers. Simply cooking more meals from whole ingredients and eating fewer packaged foods makes a dramatic difference for most people within 48 to 72 hours.
Drink More Water, Not Less
It sounds counterintuitive, but dehydration makes fluid retention worse. When your body senses low water levels, the pituitary gland releases a hormone called vasopressin that tells your kidneys to conserve water and produce less urine. Your body essentially goes into hoarding mode. Staying consistently hydrated signals that there’s no shortage, so your kidneys let go of the excess.
There’s no magic number, but aiming for pale yellow urine throughout the day is a reliable gauge. If you’ve been under-drinking and suddenly start hydrating properly, you may notice increased urination for a day or two before your body adjusts.
Eat Enough Protein
Albumin, the most abundant protein in your blood, is responsible for 75 to 80% of the pulling force that keeps fluid inside your blood vessels. When albumin drops, whether from chronically low protein intake, extreme dieting, or certain medical conditions, fluid leaks into surrounding tissues and stays there. This is why severe calorie restriction sometimes causes puffy ankles and a bloated-looking midsection even as body fat decreases.
You don’t need to eat enormous amounts of protein. Just make sure each meal includes a reasonable source: eggs, poultry, fish, legumes, dairy, or tofu. If you’re on a very restrictive diet and noticing new swelling, your protein intake is worth examining closely.
Move Your Body and Use Gravity
Your lymphatic system has no pump of its own. It relies on muscle contractions and body movement to push fluid through its vessels and back into your bloodstream. Sitting or standing in one position for hours lets fluid pool in your lower legs, which is why your ankles swell on long flights or after a full day at a desk.
Walking is one of the most effective ways to activate lymphatic drainage. Even short walks of 10 to 15 minutes every couple of hours can prevent fluid from accumulating. Calf raises, ankle circles, and flexing your feet while seated also help by engaging the muscles that squeeze lymphatic vessels in your lower legs.
Elevating your legs above the level of your heart for about 15 minutes, three to four times a day, uses gravity to move pooled fluid back toward your core. Lying on your back with your legs propped on pillows or resting against a wall works well. This is especially helpful at the end of the day when swelling tends to peak.
Compression Stockings
Compression stockings apply graduated pressure to your legs, preventing fluid from settling into the tissues. They come in different pressure levels measured in millimeters of mercury (mmHg):
- 15 to 20 mmHg: Mild support for early or minimal swelling, good for long travel days or desk jobs.
- 20 to 30 mmHg: Moderate compression for more persistent swelling or post-injury edema.
- 30 to 40 mmHg: Firm compression for chronic swelling, typically used with guidance from a provider.
For everyday fluid retention from sitting or standing, the 15 to 20 mmHg range is usually enough. Put them on in the morning before swelling starts for the best results.
Supplements and Natural Diuretics
Vitamin B6 has some evidence behind it for hormonal fluid retention. A trial of 94 women found that 80 mg of B6 taken daily over three menstrual cycles significantly reduced bloating along with other PMS symptoms like irritability and anxiety. If your fluid retention follows a monthly pattern, this is worth trying.
Magnesium also plays a role in fluid balance, and many people don’t get enough from their diet. Foods like pumpkin seeds, dark chocolate, almonds, and leafy greens are good sources.
Dandelion leaf extract has shown mild diuretic effects in a small human study. Volunteers who took the extract experienced significantly increased urination frequency and volume within five hours of their dose. What makes dandelion interesting is that it’s naturally high in potassium, containing roughly 42 to 45 mg per gram of dried leaf. Most pharmaceutical diuretics deplete potassium, so a diuretic that also supplies potassium is a useful property. That said, the research is still limited to small pilot studies, so expectations should be modest.
Hormonal Fluid Retention
Many women notice fluid retention in the days leading up to their period. Estrogen and progesterone fluctuations cause the body to hold onto sodium and water, leading to bloating, breast tenderness, and swelling in the hands and feet. This type of retention is temporary and typically resolves within a few days of menstruation starting.
The strategies above, particularly reducing sodium, staying hydrated, and exercising, are especially effective during the premenstrual window. Tracking when your swelling occurs relative to your cycle helps you anticipate it and act early rather than reactively.
Signs That Fluid Retention Needs Medical Attention
Most fluid retention is harmless and fixable with lifestyle changes. But some patterns point to something more serious. Swelling that appears suddenly in one leg, especially with pain, can be a sign of a deep vein blood clot and needs urgent evaluation. Shortness of breath, chest pain, or an irregular heartbeat alongside swelling may indicate fluid in the lungs, which can happen with heart failure.
Persistent swelling in the abdomen can signal liver damage. Rapid, unexplained weight gain of several pounds over a few days suggests your body is retaining a significant volume of fluid, not fat.
You can check the severity of leg swelling with a simple press test: push your thumb firmly into the swollen area for a few seconds and release. If it leaves an indent that bounces back immediately with only a 2 mm pit, that’s mild (grade 1). If the indent is 8 mm deep and takes two to three minutes to refill, that’s grade 4, and it warrants medical evaluation. Any swelling that doesn’t respond to the strategies in this article within a week or two, or that keeps getting worse, is worth having checked.