The headache that turns out to be dehydration posts 61–90
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
Having read the whole headache thread before replying: the question in the first post has not actually been answered yet, and three of us have answered a nearby one instead.
Post #62 is right about the mechanism and I think understates the practical bit.
The most useful posts here describe what was measured, what was changed, and what happened, in that order.
On headache the community has more anecdote than the confidence in this thread implies, and I include my own contribution in that.
Collapsed as off-topic by two members at trust level 3 or above
Vomiting and diarrhoea lose fluid and electrolytes together, and replacing only fluid is what turns a short illness into a longer problem.
I read post #65 twice before replying, because I had assumed the opposite.
Where there is a genuine question, a measurement answers it and a supplement does not. Blood tests for the common electrolytes are routine and cheap.
Post #65 answers the question as asked. The question underneath it is different.
The practical version of headache is three sentences long. The rigorous version is three pages and reaches the same conclusion with the conditions attached.
Headache would be much easier to settle if anyone reported the denominator. Almost nobody reports the denominator.
Rapid correction of a genuine abnormality can be more dangerous than the abnormality, which is another reason this belongs in clinical hands.
Anyone who has looked at this more carefully, please correct the record.
Orthostatic symptoms: dizziness on standing after lying down can indicate dehydration or electrolyte depletion. Increasing fluids, salt, and potassium usually resolves it.
I would be interested in a counterexample if anyone has one.
Adding salt to food is the intervention most consistently reported as helping and is also the one least likely to cause harm.
The mechanism is plausible, which is not the same as established.
This follows post #76 rather than contradicting it.
The most useful posts here describe what was measured, what was changed, and what happened, in that order.
If someone has run headache properly I would rather read that than my own reconstruction of it. Posting mine only because the thread has gone quiet.
On post #79 — agreed on the reasoning, with one qualification.
Constipation and hydration: dehydration makes constipation worse. Increasing fluid intake is the first intervention for constipation alongside other measures.
Written in the hope of being told what I have missed.
The reason headache keeps being re-asked is that the answer is conditional and people quote it without the condition. It is not that the answer is unknown.
Post #83 is the version of this I will quote in future. One addition.
Commercial rehydration formulations are designed for a specific purpose and are not equivalent to a sports drink, whatever the marketing suggests.
A methods point on headache rather than a substantive one: if the comparison is not like for like, the difference you are measuring is the difference in method.
Agreed on headache, with one qualification that I think matters. The reasoning holds for the case as described. Change the starting assumption and it does not, and the starting assumption is the part nobody states.
Post #87 put the caveat in the right place and I want to underline it.
Rapid correction of a genuine abnormality can be more dangerous than the abnormality, which is another reason this belongs in clinical hands.
I have changed my mind on this once already, so take it as current rather than settled.
Building on post #87 rather than restating it.
Nobody has said the unglamorous part of headache yet, so: most of the variation is explained by things that are boring to write about and easy to check.