Salt Intake for orthsotatic intolerance and Fainting

22nd February 2023 | Dr Boon Lim


Whilst salt intake plays a crucial role in managing symptoms of vasovagal syncope and orthostatic intolerance, it is important to approach it with careful consideration. While some individuals may benefit from increased salt intake, excessive salt consumption may pose risks, especially for those with certain health conditions. With this in mind, the focus on this article is mainly for patients who do not have a diagnosis of hypertension or prior heart attack or stroke history, and who have ongoing symptoms of dizziness on standing, or worsening symptoms of palpitations, shortness of breath, and lightheadness, worsened with dehydration and prolonged upright states.  

Contraindications for Excessive Salt Intake

Hypertension: Excessive salt intake can lead to an increase in blood pressure, which can be particularly concerning for individuals with hypertension (high blood pressure). It is crucial for individuals with hypertension to monitor their salt intake carefully and work with healthcare professionals to determine the appropriate level of salt restriction.

Cardiovascular Conditions: Certain cardiovascular conditions, such as congestive heart failure or kidney disease, may require sodium restriction as part of the overall treatment plan. Excessive salt intake can lead to fluid retention, exacerbate symptoms, and increase the risk of complications in these individuals. Healthcare professionals should provide guidance on salt intake based on individual health conditions.

Edema or Fluid Retention: Individuals with a history of edema or fluid retention should exercise caution with salt intake. Excessive salt consumption can contribute to fluid retention and worsen symptoms.

Your prior BP history: If you have any of these conditions listed above, you are very likely to have had blood pressure measurements taken by your GP, or other doctor or nurse specialist, at some time in the past. It is important to recognise what your usual blood pressures are:

Typically, healthy ranges are said to be below 135/85mm Hg on home BP readings. If your blood pressure readings are consistently above this levels, you may want to discuss things further with your own doctor before taking the advice to significantly increase salt intake to help with your symptoms of dizziness and orthostatic intolerance. 

Typical ranges suggested are: 

Hypertension  > 135/85mm Hg

Normal BP = between 90/60 to 135/85

Low BP  <90/60

However, individuals clearly vary! Some people may be able to comfortably tolerate blood pressures which are low, without any symptoms at all. Others, may start to “suffer” with symptoms suggestive of low blood pressure, with blood pressures within the fairly normal or “low” normal range between 100-115/60-80mm Hg, and is important to understand that there is no fixed low blood pressure at which point your symptoms of dizziness and orthostatic intolerance are worst.

A very clear example of this is often seen in our clinic setting when patients (typically above 60yo), who had been used to higher than normal blood pressures throughout their lives (for example above 140/90), who gradually failed to regulate the blood pressure on standing, and noticed a significant deterioration in symptoms of dizziness and lightheadedness and may even faint with blood pressures as “high” as 110/80. This is because the brain has gotten so used to the higher-than-normal BPs such that when BPs fall acutely to what is considered a “normal” range for most, these patients start to develop symptoms with dizziness.

In summary, with respect to salt intake, if your blood pressure is <120/80 and you feel dizzy with standing, and you do not suffer with any other cardio vascular conditions outlined above, then it is highly likely to be useful to increase salt intake.


OK... so I have been told I have low normal or normal blood pressures. Can I have salt and how much should I be having a day?

So now you know that your blood pressures are on the low side or low normal side, typically less than 120/80. Your doctor has explained that you should be having more salt in your diet. What is the best way to take this salting and how much should you have? Are there any other alternatives to salt that are easier on the palate? 

The first principle of increasing salt intake is that we should be aiming to frontload salt (and fluid) intake. That means, having most of the salt, and fluid, in the first half of the day which typically means having most of it in the morning and by lunchtime perhaps with breakfast. A typical suggestion would be to have as much as teaspoon of salt at breakfast time, and a further teaspoon of salt at lunchtime, of course with at least 500 mL of water with each of these salt boluses.

For those of you who rarely would struggle with having a teaspoone of salt in this way, having salt alternatives such as isotonic electrolyte drinks which are easily sourced from health shops, or even online (some brands commonly used by our patients include NUUN, ORS, Vitassium, SIS, Precision 1500, LMNT), but please ensure to get those that are caffeine-free with minimal sugar. Uncommon way of patients enjoy taking it, would be to have a thermos of 400 mL of (cold) water by the bedside and to pop in 1 of these isotonic effervescent electrolyte tablets into the cold water and once dissolved after 2 minutes, to drink this neat, and wait for a further 3-5 minutes before getting out of bed. A similar drink with isotonic electrolytes can be taken before lunchtime, or before engagement in any physical activity or during warmer weather particularly when sweating copiously.

Why front loaded? 

We recommend fluid and salt first thing in the morning because there is a period of dehydration which naturally occurs overnight due to insensible losses which occur from respiration, perspiration (i.e. sweating), and producing urine. This means that for the 6 – 8 hours of sleep which most people have, without any fluid intake, there will continue to be fluid losses which allows your plasma volume to be contracted and so in particular for those patients who do feel worse in the mornings, this tip of front-loaded hydration and salt may make a large to difference to symptoms!

Please see video  for more top tips on hydration,including isotonic electrolyte drinks: 



Salt intake is important in managing symptoms of vasovagal syncope and orthostatic intolerance, but it’s important to know what your resting blood pressure is and whether you have any other cardiovascular conditions as outlined above which may make increase salt intake less desirable for you specifically. In these instances, it may be useful to speak to healthcare practitioner.

However if you do have a low or low normal BP, and clear symptoms of dizziness, palpitations, shortness of breath, associated with dehydration, hot weather, standing for a long period, then it is very likely that increasing salt and fluid levels will be instrumental in helping to improve your overall symptoms.

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