If you are not worth your salt, well you aren't any good are you? So salt must be good.... Say what? Such blaspheme. Salt contains sodium and sodium is an essential element. About 40% of table salt is sodium, meaning a gram of salt gives us 400mg of sodium.
Most of us relate sodium to hypertension and thus to heart, kidney and cerebravascular disease. People with high blood pressure are at high risk of a brain hemorrhage or stroke. However, not everyone with hypertension got it from a high salt intake and not everyone who has HTN will see it normalize if they restrict their salt. Some people are salt sensitive and some are not. At this time, we really don't know which category anyone will be in unless they begin to have problems.
In our bodies, sodium is concentrated outside of cells. Sodium helps to regulate the amount of water inside or outside the cell. This a very important job. Electrolyte imbalances from dehydration can result in heart irregularities and even death. When water is lacking and the system (I think kidneys excrete salt which pulls the water from the cells) starts to take it from cells (which have already lost water), it takes minerals along with the water. It is a very dangerous situation.
Back to SALT. There is no population whose diet has been found to be too low in salt. Therefore there is much more concern about the upper limit than the lower (which may be about 200-500mg/day). What is really interesting is that if all is okay with your body, you do not have to worry about your salt intake at all.
Most all of our foods contain salt and too many of us add it, but the kidneys can filter out the extra sodium and even save some in case you swing the other way. The important thing to remember is to also drink enough water. Water will carry out the salt that is in your blood, by making urine. You should actually get rid of the same amount that you consume, on a daily basis. If you are concerned about water weight and salt making you swell, then what you need to do is drink MORE water, not less. You will pee it out. We do not gain any "pounds" from drinking water.
As I have been saying, it isn't clear that high salt intake causes hypertension, however it is clear that high calorie diets (which may also be high in sodium) increase obesity rates. Obesity is linked to HTN. Though not all people with high blood pressure see a reduction when salt intake is reduced, many people see an improvement when their WEIGHT is reduced. There is evidence that lower fat diets that are high in fruits, vegetables and grains, as well as fish and moderate amounts of low fat dairy are more health protective then simply restricting salt.
The higher ones blood pressure, the higher risk of death from heart disease, so do not think I am trying to minimize HTN, I am not. What health experts recommend is that everyone be mindful of their intake and try not to exceed the 2400mg a day limit on most days. There certainly is no harm in that.
Otherwise, if you do not have a history of kidney disease or hypertension in your family, eat your salt but drink your water too! Certain things will deplete your salt levels. Extreme physical activity, vomiting and diarrhea can alter your electrolyte balance. See a health care professional if dizziness, fainting and or headaches occur following these activities.