Hello, I'll try and answer with some ideas, I have severe ME and POTS myself so have some experience and have had rather a lot of tests over the decades. This doesn't mean the condition I have, is what you have at all (there is no autoimmune marker yet for ME or POTS), and we all differ in symptoms and reacting to different things we put in our bodies.
Observation 1:
If you had POTS, drinking salt would not stop you having tachycardia standing. It may however increase blood volume, but you don't know this as you haven't had a blood volume test to my knowledge (expensive, requires a radiological tracer, and thus hard to obtain).
A way to evaluate a suggestion of low blood volume, is to get a 24hr urine test ordered for sodium. In POTS patients, this can be significantly low. Not really in the category of low sodium diagnosis outright, but 'low normal'. Naturally you'd have to go back to your old 'diet', unless you want to see what your post sodium levels are, instead of your baseline pre intervention. (It's best to have baseline or we don't know the level of increase you'd had, after your 1/4 teaspoon salt 3x daily).
*You can monitor OI associated electrolytes and OI associated hormones yourself online, if your GP or consultant won't allow it, contact me by PM if you want to know the lab as I don't know if I post it, it's classified as advertising. It is, however expensive.
Answer to your question on BP:
You ask if you should be concerned about your BP. This is a matter for your doctor, or an online doctor if you cannot leave the house to see one. BP depends on your sex, height, weight, fluid intake, kidney function, hormone levels etc, and other medical conditions you may or may not have. So we don't know you, or what it should be. If you were a big strapping 6ft 3 guy then yes it's low, but if you're a petite slim female, it's not that low.
Observation 2:
We don't know what your BP was before the onset of your symptoms. It may have always been a bit low, this is the problem with medicine, it is massively complex with huge variables. With something so fluid as BP, then a whole host of factors can cause you to have BP fluctuations (low and high), this might be something as easy as it being a very hot day, of you'd got out the bath , or you'd have little to drink that day and were a bit dehydrated, or you just randomly had low BP at the moment in time. For greater accuracy, keep a diary of your BP, and not just related to episodes when you feel extra faint, or weak, but multiple times during the day.
Answer to your question on electrolytes:
In short, no. I would add nothing at all (including the sodium you are on), until you'd have an electrolytes blood test taken first thing in the morning when you're most 'dry'. (It is dangerous to mess around with your electrolytes as they can affect heart function and potentially caused cardiac arrhythmias or worse). Also as you don't know your kidney function at this moment in time, I would again, not mess around with this yourself, but only on the advice of a doctor who is qualified to advise you on what to do.
Safe self testing:
It is harmless, albeit a bit 'icky' to measuring fluid intake and urine output over multiple days in big plastic bottles, to check you drink enough, or not drink too much, and also to check you produce enough urine. (One classic symptom of autonomic dysfunction is to pee a lot at night, called polyuria). Sometimes I can pee 2.5L overnight (8 hours), despite my total water intake over 24hrs being only 2L. On/off I might pee 3.5 L in 24hrs, again with only a 2L input. Naturally, you then end up with even less water volume and the symptoms of OI get worse.
This means, the next day I am clinically dehydrated. My body will be al over the place with this, and 'fix' itself, sometimes going opposite and producing far too little urine output, even on days it wasn't excessively outputted, which is rather scary as I get uncontrolled thirst and back pain (kidneys) with sometimes no urine produced for up to 12hrs. (Any longer and I'd go to ER) with a strange burning tongue and feeling very dizzy.
I use this an example, because I am not on sodium. If I was, imagine what would happen during these days!
My opinion:
1)Never self diagnose any medical condition including OI, as these are circulation related and circulation is vital for life. (Hence with impaired circulation and no real treatment, severe ME CFS POTS have ruined lives).
A 'poor mans' TILT test is indeed poor, but understandable if you are blocked from this test by a hospital?Unfortunately it is not diagnostic and has no definitive measure at all about a person having autonomic dysfunction. (nb: There are many reasons for having a fast pulse standing up, including conditions that are similar to POTS, or even found in POTS patients but are a confusingly close diagnosis if only using heart rate as measure of abnormality. E.g. IST or adrenal failure, certain infections making you very weak so standing is a big load on the heart.
The reason it is necessary to always have a doctors diagnosis of all signs of symptoms?
POTS diagnostic criteria (rapid heart rate in upright posture) is poor as a measure of wide spread autonomic dysfunction. POTS doesn't require other abnormal signs or tests to be present for autonomic dysfunction at the time of diagnosis. Ironically, these are often seen in POTS patients too. (such as bowel dysfunction, seizures etc).
To complicate matters further, POTS has multiple subsets, that again, are rarely tested for other than in specialist autonomic centres. (Neuropathic/ autoimmune/hyperadrenergic/genetic/ etc).
This is why you hear about POTS patients who can play sports and even work, and POTS patients who are hospitalised or bedridden. (Confusingly, both ends of the spectrum fit the criteria, but the more sick people have far worse wide spread dysautonomia that affects so many parts of the body, that sitting up or eating is even impossible, never mind playing soccer and socialising). This phenomena doesn't help the patients, because the patients all think they need the same treatment interventions, or in fact are on the wrong treatments altogether because their 'subsets' or severe grade of illness hasn't been diagnosed correctly, because all they needed, was a TILT table test to become a POTS patient!
Patients unable to access a TILT test (99% of CFS ME) can thus presume they have condition ABC, when there is no reliable evidence for this. They are influenced by their own guess work (fuelled by understandable desperation driven by medical neglect), or by other patients (e.g. people off the internet). Again, this is understandable if a patient is blocked by medical health care services and left to their own devices to struggle. It doesn't mean though it's a good idea to continue on this path though.
Intervention with salt for OI, POTS or otherwise:
Administering sodium (salt) is potentially dangerous if you don't monitor your levels before and after to observe any changes into the red or green zones:
Generally speaking, without medical tests, such as 24hr urine Sodium (lowered levels are suggestive of low blood volume), and electrolytes blood tests, I would never mess around with my electrolytes as in extreme cases, this could be fatal if, due to messing around, huge volumes of water was drunk or your kidneys pack in as you were guessing feel faint and weak is due to something that hasn't been diagnosed, when it was something totally different. Yes, this is extremely unlikely, but possible in other people who haven't had testing.
If I was forced to, (due to blocked medical tests) I would always:
*Inform a medical professional this is my intention to take salt on a daily basis, without monitoring U&E/sodium.
*Inform a family member or person I live with I am taking supplementation that may affect me adversely.
*Monitor my blood pressure, fluid input and urine output, especially if you notice reduced urine output.
*Order tests with a private doctor to self monitor U&E's, or at least sodium.
In my view, the sensible approach in a patient with disabling O.I (undiagnosed) is to try and get a TILT table test ordered in a qualified Syncope/cardiac centre or University NHS Hospital, with an ECG/Echocardiogram/24hr blood pressure monitoring before hand. This should be a matter of course, safety wise, but check. NB: Don't jump on a TILT table without the all clear on the ECG. Do not go to a private clinic for a TILT test without evidence the people who offer these tests know your medical history. In that respect, the NHS is far safer.
Additional tests can then be ordered for OI type symptoms in a specialist syncope clinic, such as a Valsalva manoeuvre (look for exaggerated BP blood pressure over shoot (pressor response) and test for vasovagal faint. You can also you eat a meal, and see if you BP drops, and they put a cold pack on your arm to see if you BP increases. If you're quite disabled, get them to make you stand on the spot without your socks on, to see if your feet turn red, and stand up tall with your arms by your side, then turn your hands outwards (as if having an object placed in them) and see if your hands are covered in little white spots which diminish when sitting back down. All these are signs, (collectively) your circulation is impaired and your nervous system is attempting various methods to stop your fainting, such as vasoconstriction, or failing, and vasodilating - or both. In POTS instead of fainting your body is meant to produce a rampant tachycardia to compensate, thus demonstrating blood pooling. In a fainting disorder, you wont' get this compensatory measure, and you'll just black out. If that happens, it needs to be documented and investigated there is no underlying detectable cardiac problem, and it's more likely neurogenic syncope.
If it remains impossible to access medical tests, I would get a cell phone and video record the difference between sitting/standing pulse rate or laying/standing pulse rate, ideally with blood pressure readings. If you cannot get an appointment, email the video clip to a doctor and ask them if they can order you a TILT test, as you think you might have POTS or some form of problem dropping your BP with an elevated pulse (POTS doesn't usually drop your BP and POTS patients rarely faint). You can have vasovagal syncope and POTS though, I do, but I don't drop my BP like people who faint from standing upright who tend to run a low BP. In fact, some with POTS have attacks of postural hypertension, and/or narrowing of pulse pressure. If you have an arm cuff BP monitor (not wrist based), see during an episode of feeling extra ill, if when you stand up the two blood pressure levels are too close together, if so see if you can photograph this and again, show a doctor:
E.G. 110/78 sitting, laying down and 150/130 standing up. That's a classic autonomic dysfunction sign (not a gap of 40 between upper and lower figures - systolic/diastolic. Naturally, this won't be able to be shown on demand, as autonomic dysfunction, is all over the place. So if you have these attacks and struggle to stand up, document them.
NB: Don't do this on your own own if you have a history of fainting or going very wobbly. (Make sure if you're measuring BP standing up, sitting down, you have someone else in the house and you can't faint and hit your head on furniture etc). It sounds silly, but it's not if you injure yourself.
Diagnosis is essential:
Without a TILT test you will be unable to have a neurological/cardiogenic diagnosis and the possibility of medications, used in POTS or syncope disorders. In some people, these can help a lot, although there are side effects of medications that many patients cannot tolerate (Beta blockers, Midodrine etc), so a positive outcome is unsure not certain.
I hope that helps. Whenever possible with a condition like POTS rule everything out that affects brain/heart/lungs/circulation/hormones before going down the route of self belief, in any medical condition, as without monitoring, you don't know the positive or negative effects you feel are down to the compound you're ingesting.
Take care.
