Salt is made up of sodium and chlorine (chemical name: "sodium chloride"). But there are other forms of sodium in food, including baking soda (sodium bicarbonate) and food additives, such as monosodium glutamate, sodium nitrite, and sodium benzoate. Any form of sodium adds to your overall daily intake, but salt makes up about 90% of the sodium we consume.

The human body needs some sodium for proper functioning. Sodium helps regulate your blood pressure and blood volume, the balance of other fluids in your body, and it helps with the function of your nerves and muscles.

However, your body needs only 180 mg to 500 mg a day to function properly. That's less than the amount in 1/4 teaspoon of salt.

Only about 6% of our daily sodium comes from salt added at the table. Another 5% comes from salt added during cooking. Most of the rest -- up to an estimated 77% -- comes from processed or restaurant foods. The easiest way to cut down on your sodium  intake is to eat more home-cooked meals made from fresh ingredients.

By far, the biggest health problem caused by a high-salt diet is high blood pressure. On average, the higher your salt intake, the higher your blood pressure. And high blood pressure increases your risk for stroke, kidney problems, heart failure, blindness, and heart attacks.

You can help counter the negative effects of a high-salt diet with physical activity. Studies show that the more physically active you are, the less your blood pressure rises in response to a high-salt diet. Consequently, researchers say if you live a sedentary lifestyle, you need to pay particular attention to reducing your salt intake.

Too much salt can have detrimental effects on the heart, kidneys, and blood vessels. According to the CDC, excess sodium can increase your risk for a heart attack or a stroke.

The National Academy of Science's Institute of Medicine recommends that healthy adults limit their sodium intake to less than 2,300 mg per day -- about the amount in one teaspoon of table salt (which is about 40% sodium). On average, Americans consume more than 3,400 mg of sodium per day -- or the amount contained in about 1 1/2 teaspoons of salt.

Certain populations are more prone to high blood pressure or at risk from its effects. For these groups -- including people 51 years of age or older, African-Americans, or people who have high blood pressure, diabetes, or chronic kidney disease --1,500 mg per day is the recommended maximum intake of sodium. Some people may need to consume even less.

Men consume more dietary sodium than women, mainly because they simply eat more food. On average, American men consume between 3,100 mg and 4,700 mg of sodium per day; women consume between 2,300 mg and 3,100 mg.

Sodium isn't all bad; it occurs naturally in most foods and can perform several important functions in the food supply. Salt and other forms of sodium are used to bind and stabilize ingredients and as preservatives, flavor enhancers, and color enhancers.

While ordinary flour may contain no sodium at all, self-rising flour includes leavening, which typically contains large amounts of sodium in the form of baking soda and salt. Because of that, flour contributes to the surprising amounts of sodium in baked goods.

According to the CDC, bread products contribute 354 mg of sodium per day to the average American diet. Other surprising sources of salt include dairy products (one cup of low-fat cottage cheese contains 918 mg); canned soups, sauces, and vegetables (one cup of canned tomato sauce has 1,284 mg); and deli meats (two slices of salami have 822 mg).

It can take a while to adjust to a low-salt diet. Salt is an acquired taste, but most of us acquired it as children. As adults, after years of eating overly salted foods, we have to make a committed effort to changing our palates. Experts say on average it takes 8 to 12 weeks.

Table salt, sea salt, and kosher salt are all the same thing: sodium chloride. And they all have the same sodium content (40%). The differences are primarily in texture and taste.

Table salt is made from rock salt harvested from inland deposits (with iodine sometimes added as an extra nutrient). Kosher salt is made from similar sources, but it's usually additive-free and has a coarser texture. Sea salt, as its name suggests, is harvested from evaporated seawater. Consequently, it has a slightly different flavor. In the end, though, they all contribute equally to your total sodium consumption. 

Most sports drinks contain electrolytes, which are minerals found in the bloodstream; they include sodium, potassium, and calcium. Electrolytes in sports drinks are meant to replenish the losses through sweat during exercise, but if you drink them without sweating enough to lose these minerals, you could be increasing your sodium intake.

Food labeling rules allow up to 5 mg per serving in a product labeled "sodium-free." Products labeled "very low-sodium” are allowed to have up to 35 mg per serving; "low-sodium" means 140 mg or less; "reduced sodium" means the usual sodium level has been cut by at least 25%; and "unsalted," "without added salt" and “no salt added” mean that it contains no additional salt beyond the amount that occurs naturally in the food.