Is Salt Bad For Kidneys?

The average salt, or sodium, intake of an American is about double the daily recommended amount of 5 grams. And, while sodium is essential for many bodily functions, too much may be bad for the kidneys.

Good Salt 

Humans need sodium to survive. Our bodies use salt to transmit nerve impulses, control muscle contractions, and balance our fluid levels. (1) Too little salt will force the kidneys to keep water and therefore keep salt around. 

Bad Salt

Too much salt will cause the kidneys to go into overdrive. The only way to remove the excess salt is by filtering and pushing out as much water as possible. Unfortunately, this forces more protein into urine, which acts as a risk factor of kidney damage. (2) If the salt sticks around, it’ll enter the fluid around cells, bringing with it more water. The extra volume of fluids makes the heart work harder, putting extra pressure on blood vessels. If this happens consistently, these vessels can stiffen and damage. (1)

Blood Vessel Health Matters

The kidneys are, essentially, thousands of tiny blood vessels and arteries. The blood enters through the renal artery, is filtered, and then removed through the renal vein. If these veins are damaged, it will seriously impact their ability to work. Over time, fewer toxins will be able to be filtered from the blood, causing more damage. (3)

Salt and Kidney Stones

High salt intake forces the kidneys to remove more water than they normally would. Their goal is to balance sodium levels to regulate blood pressure. During this process, calcium is also pulled along and removed via urine. As a result, calcium may build up and form a “stone”.

The Takeaway

So, salt is not innately bad for the kidneys. In fact, sodium is extremely necessary! It’s only when consumed in excess does salt becomes bad for them. 

Speak with your healthcare provider regarding your salt intake, blood pressure, and kidney health.