I've tested low for sodium for at least 15 years. By low I mean around 130-131. Is there anything I can d to bring this up? I can eat salt all day long and it has no effect on my blood tests. All it does is make me thirsty.

Note: I used to drink a lot of water. Now, I try to be aware and limit myself to less than 1.5 liters per day. I think my total fluid intake is now pretty close to normal.

Thanks!