low sodium level or hyponatriemia

my father is 74 and suffering from cardiac and diabetic problem with specially cervical nerve compression on c3-c4, 5-6 6-7 also.
Last auguest28, 2010 I have checked his sodium and potasium level and I found that is hyponatrimic and his na+ level is on 116. I have tried all suggestion from here dr in india as it on my place. But still his na+ level is not coming at normal level.
Presently his na level is 123 mmol/l. he is taking orally 5-8 gm pure salt  in water.
some more deatils:
weight 100 kg
obese
liver and kidney function test is right.
cbc reports are normal.
urine out put nearly 4 liter
intake fluid : nearly 4 liter
spot urine sodium was last month: 35mmol/l
sleep apnea is present due to obesity
cardiac problem two year back doing angiography and there was bloackage in veins.no possible cabg due to diabetes and age.
also suffering from chf

What should I do in this position.
If you know some solution please tell me.
I will thankful for it.
thanks v

[Dr Sharma]

Hi there. Your father has a cardiac history of blocked vessels, not corrected with angioplasty due to other co morbidities diabetes, congestive heart failure. Hyponatremia is defined as Serum Na levels less than 135 mmol/L. It can develp due to excessive free water if received hypotonic solutions during a hospital stay, excessive renal or extrarenal losses of Na or renal retention of free water and deficient intake of Na, though less common.
I understand your concern, but self treatment of hyponatremia at home can be very dangerous since he has congestive heart failure where you have to restrict salt and fluids to contain edema and pulmonary edema. So my advice to you is that do not increase sodium intake unmonitored. Sudden increase in serum sodium levels is also associated with central pontine myelinosis.
Please show him to a physician and he would be the best judge if this hyponatremia needs correction at all in the background of other diseases he has or if this can be left untreatment if asymptomatic.
Hope this helps. Take care.