Salt - How do you know if you are taking enough salt?

The first way to tell if you are getting enough salt and water is called "clinical assessment:"How do you feel? Do you feel better? If you take more, do you feel better or not?

The next question - do you feel better when you take more but you can't keep it up. It might make your mouth hurt or your stomach hurts or is upset - or you just can't stand to take any more. Then, it's time to talk with your doctor about adding medication that will help hold on to the fluid/salt you are getting in.

The third way is to do the urine test. (Described below)

How do you know if you are getting too much?

There are two ways to tell if you are getting enough salt and water. The first way to tell is "clinical assessment" and the physical exam. Many of the physicians treating POTS and NMH start with this approach.

Clinical Assessment

If you taking in more than your body needs inside the blood vessels, the extra fluid will go outside the blood vessels, and collect in the other tissue in your body. You will get "edema" or puffiness in your feet/ankles.

When you are getting more than your body needs for your Orthostatic problem, the extra fluid will collect in the "dependent" parts of your body, the parts of your body that are closest to the floor. When we stand most of the day or sit with our feet on the floor, the dependant parts of our body are our feet, then our ankles and then the lower legs.The fluid could collect in the feet first. If it continues longer, there would be fluid around the ankles and then up the leg. It would first be noticed in the feet, socks or shoes might feel tight. Socks might leave ridges in the skin at the end of the day. The skin might look puffy and shiny.

(If you are sitting in a recliner with your legs up, the most "dependent" or lowest part of your body would be your buttocks. If you are lying in bed most of the day, your buttocks and back would be the dependant part; that is where you would check for fluid collecting.)

How to test to see if you have edema: You can test for edema. Take your 1st finger and gently press on the skin over a bone in the foot or along side the ankle bone. You don't need to press hard, just gentle. Hold your finger there while you count to 30 seconds and then take it off. You might see a dent in the skin where your finger was. If you can't see a dent, run your finger lightly over the skin. Can you feel a little dent? This is called "pitting edema" because it left a "pit" when you pressed on the skin.

One physician's observation: Fludrocortisone is a medication used to retain fluid and salt, Dr. Figuero describes the clinical assessment of fluid status using fludrocortisone: "If the patient gains 3 to 5 pounds (1.2-2.3 kg) and develops mild dependent edema, you can infer that the plasma volume has expanded adequately." Here, we are talking about expanding the amount of plasma (plasma volume) enough just with salt and water!1

  How do you tell the difference between this and the edema that comes with blue legs?

You may already gets blue/red legs & edema when you stand too long. Usually, the blueness, pinkness or mottling & edema develops after standing awhile, like in the shower. You may also get blueness in your lips or hands also. It usually goes away with lying down. If there is swelling in your legs that stays, then you would need to check to see if the swelling/edema is more than your 'usual'. You might have to use a tape measure to measure the size of you leg & see if it changes. If it does not go away now, talk it over with your doctor.

What to do if you think you have edema:Edema suggests you have reached your body's limit for fluid and salt. You should skip your next dose of salt and contact your doctor for more guidance on how much salt you should take. Have your diary/log ready to share what you have been taking and when you first noticed the swelling/edema.

If you have edema and are having a hard time breathing when you lie down (hint - you don't lie down anymore, you sit up to rest or sleep), you have started a new cough, or you are having pressure or heaviness in your chest, you should contact your physician immediately so that you can be seen. You need to be seen and evaluated.

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The Urine Test

This is a 24-hour collection of urine. The laboratory provides plastic bottles with special chemicals in them for you to use to save your urine. The urine is measured to see how much urine you put out in 24 hours (output, volume) and how much sodium there is in the urine.

  • If there is more than 170 mmol of sodium and urine volume more than 1500 ml in 24 hours, you are getting enough salt and fluids. 2,7
  • If there is less than 170 mmol, try up to 6 grams a day, divided up into 3 doses.1,4
  • If there is less than 100 mmol (100 mEq), it would suggest that low fluids/volume.5

The test is not often done to check on how much salt is enough. Most clinicans rely on the clinical assessment and physical exam. It is usually only done when the clinical information is confusing or there are other medical conditions present and the inforamtion is needed to sort out the clinical situation..

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Why You Need to Raise the Head of Your Bed - and How Much


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Author: Kay E. Jewell, MD
Page Last Updated: September 13, 2012