Dizziness on standing: the ordinary explanation first

Posting this under the heading it deserves: Dizziness on standing: the ordinary explanation first Everything below is what sits behind that.

A hydration and intake question, with the figures, since this one is unanswerable without them.

Fluid intake over a day, roughly, plus what I take with it and when. Intake is down substantially on where it was, which I gather is the ordinary consequence of eating much less rather than anything else.

What I would like to understand is which of the symptoms attributed to this are plausibly about fluid and salt, and which are being attributed there because it is the easy explanation.

The opening post describes the usual case. This is about the unusual one.

Nobody has said the unglamorous part of dizziness on standing yet, so: most of the variation is explained by things that are boring to write about and easy to check.

I would put moderate confidence on the mainstream reading of dizziness on standing and no more. That is not scepticism for its own sake; it is where the sourcing actually stops.

Orthostatic symptoms: dizziness on standing after lying down can indicate dehydration or electrolyte depletion. Increasing fluids, salt, and potassium usually resolves it.

Correct me on the arithmetic if it is wrong; I would rather know.

The arithmetic in post #4 is right; the assumption feeding it is the part to check.

The very ordinary causes of week-two malaise: inadequate hydration, low sodium intake, too-rapid calorie deficit, and inadequate sleep are more common causes of fatigue and malaise than compound toxicity.

Adding it in case it saves somebody the afternoon it cost me.

The question underneath dizziness on standing is usually "how would I tell?" rather than "what is true?", and that one has a method attached to it.

Write down what you would expect to see under each hypothesis before you collect anything. If they predict the same observation, collecting it will not help.

Adding salt to food is the intervention most consistently reported as helping and is also the one least likely to cause harm.

Adding it because I spent an afternoon working it out and nobody should have to twice.

Worth separating dizziness on standing as a question about the compound from dizziness on standing as a question about the documentation. They get answered by different people and only one of them is answerable here.

Commercial rehydration formulations are designed for a specific purpose and are not equivalent to a sports drink, whatever the marketing suggests.

Not a strong opinion, just a consistent one.

If someone has run dizziness on standing properly I would rather read that than my own reconstruction of it. Posting mine only because the thread has gone quiet.

I read post #9 twice before replying, because I had assumed the opposite.

Constipation and hydration: dehydration makes constipation worse. Increasing fluid intake is the first intervention for constipation alongside other measures.

I am confident about the direction and much less about the magnitude.

The most useful posts here describe what was measured, what was changed, and what happened, in that order.

Caveat: everything above assumes the paperwork is what it says it is.

The practical version of dizziness on standing is three sentences long. The rigorous version is three pages and reaches the same conclusion with the conditions attached.