I agree with Trapper about the salt. The question is why does salt help.
Think adrenals;
"If the adrenals are weak, then even normal thyroid activity places an excessive burden on them. One may begin to feel 'hypoadrenal' (coldness, weight loss, dryness, fatigue, insomnia, and/or anxiety) and then the body innately turns down its own thyroid energy production by increasing production of RT3.
Conversely, if the adrenals are strong and the thyroid is weak or unable to keep up with the adrenals, one begins to feel 'hypothyroid' (heat intolerance, weight gain and fluid retention, tiredness, excessive need to sleep and/or depression). A very common error is to focus entirely on the thyroid and ignore the adrenals."
http://www.healingnaturallybybee.com/articles/treat19.php
In my case I had done the watercure for a year before I started on iodine. I have healed my adrenal fatigue paralell with my hypo T. Due to the salt possibly. I have a craving for salt, I believe it is the adrenals telling me something. The adrenals also are the organ single most dependent on vitamin C. So I take it several times aday.
Again I need to remind of the importance of boron. It stops an excessive urination in hours, days. The water are utilized in the cells instead of running through, or / and being retented in a waiting for the right electrolyte balance. This I dont have from books or links, it is purely what I have seen in some cases.
"Improves Cardiovascular Problems
Managing heart ailments like congestive heart failure can be much easier with adequate boron intake. CHF that is typically marked by poor functioning of the heart, causes breathing problems, fluid retention in the legs, weight gain and decrease in appetite. Intake of boron through diet or in supplemental form can play a crucial role to improve CHF symptoms."
http://www.buzzle.com/articles/boron-health-benefits.html
You have migraine; there is a magnesium deficiency behind here. Boron adresses that too, as long as you get enough magnesium, in the right form.
http://www.relieve-migraine-headache.com/magnesium-migraines.html