Your kidneys are the primary tool your body uses to reduce sodium, and in most cases, they handle the job without much help. Nearly all sodium leaves your body through urine, with a small amount lost through sweat. The real key to lowering sodium levels isn’t a quick detox. It’s reducing how much sodium you take in while supporting your kidneys’ ability to flush the excess out. For healthy adults, the recommended daily limit is 2,300 milligrams, roughly one teaspoon of table salt, yet most people regularly exceed that.
How Your Body Manages Sodium
Your kidneys filter your entire blood volume many times a day, and they’re remarkably precise at matching sodium excretion to sodium intake. Between 90% and 99% of the sodium they filter gets reabsorbed back into your bloodstream, with the remaining fraction exiting in your urine. When you eat more salt than usual, your kidneys adjust by concentrating more sodium in your urine rather than producing more urine overall. This is why simply drinking extra water doesn’t “flush” sodium the way many people assume.
In the first few days after a spike in sodium intake, your body does retain extra fluid, which shows up as temporary weight gain and puffiness. But the kidneys gradually catch up. The process works in reverse, too: when you cut back on sodium, your kidneys conserve less and excrete more until a new balance is reached. This adaptation typically takes a few days, which is why the effects of a high-sodium meal (bloating, thirst, elevated blood pressure) are temporary for most healthy people.
Cut Back on the Biggest Sodium Sources
About 61% of the sodium in the average American diet comes from store-bought prepared foods and restaurant meals, not the salt shaker on your table. Data from a national nutrition survey found that nearly 44% of all sodium consumed comes from just ten food categories:
- Bread and rolls
- Pizza
- Sandwiches
- Cold cuts and cured meats
- Soup
- Burritos and tacos
- Salted snacks (chips, pretzels, crackers)
- Chicken (often injected with salt solutions before packaging)
- Cheese
- Eggs and omelets (especially from restaurants)
The surprise on this list for many people is bread. A single slice can contain 100 to 200 milligrams of sodium, and because most people eat several servings a day, it adds up fast. Canned soups are another common offender, with some brands packing over 800 milligrams in a single serving.
The most effective dietary change is cooking more meals at home using whole, unprocessed ingredients. When you do buy packaged food, compare nutrition labels and choose the lower-sodium option. Look for products labeled “low sodium” (140 mg or less per serving) rather than “reduced sodium,” which only means 25% less than the original and can still be high.
Eat More Potassium-Rich Foods
Potassium directly increases how much sodium your kidneys excrete in urine, making it one of the most effective dietary levers for lowering body sodium. It also helps relax blood vessel walls, which independently lowers blood pressure. The ratio of sodium to potassium in your diet matters as much as the absolute amount of either one. People with the lowest sodium-to-potassium ratios consistently show lower rates of hypertension.
Good sources of potassium include bananas, potatoes, sweet potatoes, spinach, avocados, beans, yogurt, and oranges. A medium baked potato with skin delivers around 900 milligrams of potassium, and a cup of cooked spinach provides roughly 840 milligrams. Most adults should aim for about 2,600 to 3,400 milligrams of potassium per day, depending on sex, though many people fall short.
One important caveat: if you have kidney disease, your kidneys may not handle extra potassium well. The same applies if you take certain blood pressure medications that already cause potassium retention. In those cases, loading up on potassium-rich foods can cause its own problems.
What Water Actually Does (and Doesn’t Do)
A common piece of advice is to “drink more water to flush out sodium.” The reality is more nuanced. Research on sodium and fluid balance shows that when sodium intake increases, your body adjusts by concentrating more sodium in the urine rather than producing a larger volume of urine. In a steady state, urine volume stays roughly the same across a wide range of sodium intakes.
That said, staying well hydrated does support your kidneys’ ability to function efficiently. If you’re dehydrated, your body holds onto both water and sodium more aggressively. So adequate water intake is important, but drinking excessive amounts won’t speed up sodium clearance in a healthy person. The goal is steady, normal hydration, not forcing fluids.
Exercise and Sweat
Physical activity does cause sodium loss through sweat, and the amounts can be significant. During moderate exercise in warm conditions, a person loses roughly 480 to 600 milligrams of sodium per hour through sweat alone. Over a full day of physical work in the heat, total sodium losses can reach 4,800 to 6,000 milligrams.
For someone trying to bring down high sodium levels from a salty diet, regular exercise offers a meaningful assist. Even a moderate 30- to 60-minute workout can account for several hundred milligrams of sodium loss. But this should be seen as a complement to dietary changes, not a replacement. You can’t reliably out-exercise a high-sodium diet, and intense sweating without adequate fluid replacement creates its own risks.
Salt Substitutes: Helpful With Caution
Salt substitutes sold in grocery stores typically replace sodium chloride with potassium chloride. They taste similar to regular salt (though some people notice a slightly metallic or bitter edge) and can help you reduce sodium intake while still seasoning food. Other flavor-boosting strategies include using lemon juice, vinegar, garlic, herbs, and spices to make lower-sodium food more satisfying.
Potassium-based substitutes aren’t safe for everyone. Mayo Clinic experts advise caution for people with kidney disease, heart disease, liver disease, diabetes, or high blood pressure, and for anyone taking blood pressure medications like ACE inhibitors. These conditions and medications can impair your body’s ability to clear excess potassium, and elevated potassium levels are dangerous in their own right.
Your Taste Buds Will Adjust
One of the biggest barriers to cutting sodium is that low-salt food initially tastes bland. This is temporary. Your palate adapts to lower sodium levels, and foods that once seemed underseasoned start tasting normal. Most people report that this shift happens within two to three weeks of consistently eating less salt. After the adjustment, foods you previously enjoyed often taste unpleasantly salty.
A gradual approach works better than going cold turkey. Reduce sodium by a little each week, and rely on other flavoring agents (acid, heat, herbs, umami from mushrooms or tomatoes) to fill the gap. Over time, you’ll become more sensitive to salt and need less of it to feel satisfied.
When Sodium Drops Too Low
While most people benefit from eating less sodium, it is possible for blood sodium to fall too low, a condition called hyponatremia. This is defined as a blood sodium level below 135 milliequivalents per liter. It rarely results from simply cutting salt in your diet. It’s more commonly caused by drinking excessive amounts of water (especially during endurance exercise), certain medications like diuretics, or underlying conditions affecting the kidneys, liver, or heart.
Mild hyponatremia (130 to 135 mEq/L) can cause fatigue, weakness, difficulty concentrating, and unsteady walking. Moderate cases (125 to 130 mEq/L) bring increased drowsiness, nausea, and muscle cramps. Severe hyponatremia (below 125 mEq/L) is a medical emergency that can cause confusion, seizures, and loss of consciousness. If you’re reducing sodium and experience persistent headaches, unusual fatigue, or mental fogginess, it’s worth having your levels checked.
For the vast majority of people, the far bigger risk is too much sodium, not too little. About 45% of American adults have hypertension, and excess sodium intake is a major contributor. Bringing your daily intake down to or below the 2,300-milligram guideline, while eating plenty of potassium-rich whole foods, is one of the most impactful changes you can make for long-term cardiovascular health.