Sodium deficiency?

Hi. I’ve been doing a huge diet/exercise thing since June 1, about 1 hour/day exercise (stationary bike) + calorie deficit (~1500 cal/day). I’m not a big person, 5’6" 59yo male so this is intense but not nuts. I’d lost 38 pounds in 3 months, which isn’t that crazy a rate. Intense, but not crazy. I’ve been eating good food in smaller quantities, no alcohol, no silly Keto or Paleo or whatever fad, just the old fashioned thing: eat less and exercise. I’m now at 150 pounds: a really good place.

So, anyway: I went for blood work 8/25 and had a sodium deficiency. 128/whatever the scale is. Google says this can happen if you overhydrate; I hadn’t been. I stopped the diet September 1 and started eating normally (probably 2500-3300/cal a day, I stopped measuring) and doing light (<40 min/day) exercise, not strenuous just activity. Little or no sweating, very measured.

Sept 7 I still had a sodium deficiency, about 128 again. I have not been over hydrating, I’m just drinking coffee, water when thirsty. I eat tons of salt on food so I get plenty of sodium.

My doctor today told me she wants to do one more blood test, and if I’m still deficient wants to do a CTI of my lungs and brain. I’m kind of freaked about this. The last time I got in shape at 52 (7 years ago) my PSA tested abnormal and I was eventually diagnosed with prostate cancer. I had surgery 3.5 years ago, so far I’m cancer free. Now this.

So, what freakout level should I be at here? Thanks in advance.

PS, I’m doing another ultra-sensitive PSA test on Friday, which would detect my cancer coming back. As of 6mo ago it hadn’t, so I’m not expecting surprises there :crossed_fingers:

Since you Googled hyponatremia, you probably saw all the symptoms. Are you symptomatic? Why were you having blood work? Before you panic, you might wait until you go back and repeat the test. Remember that tests have normal ranges, but there’s the occasional outlier that’s still normal. If your Na is still low, you might ask your doctor what, exactly, she’s looking for on the scans.
Share your concerns with your physician. (I am a retired doctor, but I hope this doesn’t qualify as medical advice and overstep the SDMB rules.)

I was symptomatic on 8/25: extreme fatigue for a couple of days. Since then I’m fine.

I had high cholesterol and weird liver numbers and was following up after doctor told me to lose weight in May. Liver numbers are nominal now. Cholesterol I’m getting on next test (we had a miscommunication).

This will be the 3rd sodium test upcoming.

Only partially facetious, but maybe I should have clickbaited my thread:

My Doctor wants to CTI my lungs and brain

Because I had low sodium.

</boring details>

I mean, I seriously buried the lede in my OP. Who is going to read all the way down to " My Doctor wants to CTI my lungs and brain" near the end? Thanks for reading this far I guess :slight_smile:

The lungs thing rings a bell. I had a series of marginally low sodium readings, and the doctors tried a series of things, including an X-ray of my lungs. I forgot what it was they were checking, but I assume they’re ruling out all sorts of possibilities, however remote.

(In my case, the specialists made some offhand remark about “restriction of fluids”, I cut back on the amount of tea I was drinking, and, lo and behold, the next blood test was back in the normal range. Are you sure your fluid intake isn’t the culprit?)

Pardon my pedantry, but ‘sodium deficiency’ is a pretty uncommon development in adults. Having a low level of sodium in the blood is almost always due to having an excess of water in the blood, i.e. the sodium has been diluted, but it is not ‘deficient’. As noted above, this is called hyponatremia.

There are many causes of hyponatremia but some of the more common ones include a side effect of medications that causes the body to hold on to too much water (but not to lose sodium), heart failure, and cirrhosis.

There is a condition called SIADH (Syndrome of Inappropriate Anti-Diuretic Hormone) which causes hyponatremia. It has many causes including the use of certain medications and various types of lung disease.

It is possible to drink so much water that it dilutes your blood sodium but that is pretty hard to do - assuming your kidneys are normal and you’re on no meds that lead to your body holding onto water, you’d need to drink at least around 10 liters of in a day (over 10 quarts).

Another cause of low blood sodium (but not very common) is a grossly inadequate dietary intake of protein. This typically occurs in people who live on beer and not much else, or the proverbial little old lady who eats nothing but ‘tea and toast’.

Whelp, 3rd blood test(s) in 3 weeks. Sodium is still low at 129 mmol/L where 135-146 mmol/L is normal, and was about the same on three tests over three weeks. On the plus side my PSA is undetectable, so my prostate cancer hasn’t yet returned.

I see my doc this Thursday in person. Her office wanted to send me straight to specialists and CTI scans but I wanted to get a face-to-face and hear from her what the possibilities are. I’ve been somewhat fatigued, even dizzy at times, though perhaps that’s just being run down and unrelated.