Water retention happens when excess fluid builds up in your body’s tissues, causing puffiness, bloating, and swelling, most commonly in your hands, feet, ankles, and legs. The good news: most cases respond well to simple changes in diet, movement, and daily habits. Here’s what actually works and why.
Why Your Body Holds Onto Water
Your kidneys constantly fine-tune how much fluid stays in your body. They do this primarily by adjusting how much sodium they reabsorb. A hormone called aldosterone, produced by your adrenal glands, tells your kidneys to hold onto sodium when your body senses it needs more fluid. Since water follows sodium, retaining more sodium means retaining more water. The net effect is that your body holds onto fluid at roughly the same concentration as your normal bodily fluids.
Another hormone, antidiuretic hormone (ADH), plays the opposite side of the equation. When you’re dehydrated, your body ramps up ADH production, telling your kidneys to hold onto water. When you drink enough, your body stops signaling ADH release, and your kidneys let more water pass through as urine. This is why drinking more water can paradoxically help you stop retaining it.
Cut Back on Sodium
Sodium is the single biggest dietary driver of water retention. When you eat a high-sodium meal, your body pulls water into the spaces between your cells to dilute the excess salt, and you wake up puffy the next morning. The Heart Failure Society of America recommends keeping sodium between 2,000 and 3,000 mg per day for people prone to fluid issues, with a stricter limit of under 2,000 mg for more severe cases.
Most people consume far more sodium than they realize, because roughly 70% of it comes from packaged and restaurant food, not the salt shaker. The fastest way to reduce sodium intake is to cook more meals at home and read labels. Canned soups, deli meats, frozen dinners, soy sauce, and bread are some of the worst offenders. Swapping these for fresh alternatives can produce noticeable results within a day or two, since your kidneys will begin flushing the excess once your sodium levels drop.
Drink More Water, Not Less
It sounds counterintuitive, but restricting water makes retention worse. When your body senses dehydration, it increases ADH and holds onto every drop it can. Staying well-hydrated does the opposite: it signals your kidneys that there’s plenty of fluid available, so they release more through urine. There’s no magic number, but aiming for enough water that your urine stays a pale straw color is a reliable guide. If you’re already retaining fluid, gradually increasing your intake over a few days gives your body time to adjust and start releasing the excess.
Move Your Body, Especially Your Legs
Gravity pulls fluid into your lower extremities whenever you sit or stand for long periods. The main mechanism that pushes it back up toward your heart is a set of muscle pumps in your feet and calves. Every time you take a step, the soles of your feet compress deep veins like a hydraulic pump, while your calf muscles squeeze blood upward through a system of one-way valves. Each pump cycle moves roughly 33 mL of blood into the vein behind your knee, and these pumps collectively overcome the roughly 90 mmHg of pressure that gravity creates when you’re standing still.
This means walking is one of the most effective things you can do for swollen legs and ankles. Even simple calf raises or ankle pumps (pointing and flexing your feet) activate this system when you can’t get up and walk. If you sit at a desk all day, set a reminder to get up and move for a few minutes every hour. Elevating your legs above heart level when resting also helps fluid drain passively back toward your core.
Try Compression Socks
Compression stockings apply graduated pressure to your legs, tightest at the ankle and gradually looser toward the knee or thigh. This external pressure mimics what your muscles do during movement, pushing fluid out of the tissue and back into circulation. They’re available in several pressure levels: 15 to 20 mmHg for mild everyday swelling, 20 to 30 mmHg for moderate retention, and 30 to 40 mmHg for more significant fluid buildup. For general water retention, the 15 to 20 mmHg range is usually sufficient. Put them on first thing in the morning before gravity has a chance to pull fluid into your legs.
Combining compression with manual lymphatic drainage massage can further reduce swelling. Research supports this combination for significantly reducing the volume of swollen areas by increasing lymphatic activity. You can do a simplified version at home by gently stroking your skin in the direction of your lymph nodes (toward your groin for your legs, toward your armpits for your arms) using light, rhythmic pressure.
Increase Potassium-Rich Foods
Potassium works in direct opposition to sodium in your body. While sodium pulls water into the spaces between cells, potassium helps move it back inside cells and signals your kidneys to excrete more sodium. Eating more potassium-rich foods is one of the most effective dietary strategies for reducing retention. Good sources include bananas, avocados, sweet potatoes, spinach, beans, yogurt, and salmon. Rather than focusing on supplements, getting potassium from whole foods gives you a steadier supply and avoids the risk of taking too much, which can affect heart rhythm.
Consider Magnesium and Vitamin B6
Both of these nutrients show real evidence for reducing water retention, particularly the bloating and swelling tied to the menstrual cycle. A clinical study found that 200 mg of magnesium daily improved water retention associated with PMS. A follow-up study found even better results with 250 mg of magnesium combined with 40 mg of vitamin B6. Separately, a double-blind, randomized controlled trial in 94 women found that 80 mg of vitamin B6 taken daily over three menstrual cycles significantly reduced bloating and other PMS symptoms.
If your water retention tends to follow a monthly pattern, trying one or both of these supplements is a reasonable starting point. Magnesium-rich foods like dark chocolate, nuts, seeds, and leafy greens can also help you increase your levels without a supplement.
Other Habits That Help
Refined carbohydrates contribute to retention because your body stores each gram of glycogen (stored carbohydrate) with about 3 grams of water. Cutting back on heavily processed carbs, especially sugary snacks and white bread, can reduce the amount of water your body locks into glycogen stores. This is also why people lose several pounds of “water weight” in the first few days of a low-carb diet.
Stress raises cortisol, which directly increases ADH production and tells your kidneys to retain fluid. Chronic stress can keep this cycle running indefinitely. Sleep deprivation has a similar effect. Getting consistent sleep and finding ways to manage stress, whether through exercise, meditation, or simply spending less time in fight-or-flight mode, can reduce the hormonal signals that cause your body to hold onto water.
When Swelling Needs Medical Attention
Most water retention is harmless and responds to the strategies above. But certain patterns of swelling signal something more serious. Pitting edema, where pressing your finger into swollen skin leaves a visible dent that takes several seconds to fill back in, should be evaluated by a doctor, especially if it appears suddenly or without an obvious cause like a long flight or a salty meal.
Seek prompt medical attention if your swelling comes with pain or skin discoloration in the swollen area, an open sore on swollen skin, shortness of breath, swelling in only one limb (which can indicate a blood clot), or difficulty walking. These symptoms can point to heart, kidney, or liver problems, deep vein thrombosis, or other conditions that need treatment beyond lifestyle changes.