can a blood test indicate that you've been dehydrated for some time ,or would it just measure dehydration on the day the blood was taken

[gingeroots]

That's it really .
Just wondering as my mum generally drinks a fair amount but not on days when she has a hospital appointment .
So factoring in early stressful start ,long wait once arrived ,hottest weather of year I'm wondering if what the nurse barked at us
" Yes but the blood test shows that your mother has been dehydrated for weeks "
is entirely accurate .
I do realise that in common with a lot of elderly people she probably needs to drink more than she does ,and also how critical it is that she does drink enough .

A really PCV would be indicative, but not diagnostic of prolonged dehydration.

urine samples give better results afaik

Thank you .

Blood tests can confirm dehydration, especially the electrolytes tests which check liver and kidney functions.

If your mum is drinking more than 2 litres a day then one day without drinking would not make much difference, so are you sure she is drinking. Tea and coffee don't count.

I have to drink 2-3 litres a day but recently haven't. My last blood test showed I have kidney failure, white cells and neutrophils are sky high and liver function tests are off the scale. Needless to say I got a,lecture off the doctor who rang me and his first question was how much I am drinking.

Doctors, nurses can also tell by looking at your skin and veins and get a picture of dehydration

Re the urine tests, dark urine is also a good indication of dehydration, and also constipation

Yes ,all makes sense .
Urine is pale not dark .
Has kidney failure ,takes 100mg diueritics daily ,all a difficult balancing act .

But is 92 and needs to be encouraged .
Speaking to her kindly and acknowledging impact of heat ,stress of hospital visit rather than going into full confrontional mode would have been more helpful .
Telling her off will make her switch off and ignore advice .

And I wouldn't regard tea as not counting .
www.nhs.uk/news/2011/03March/Pages/tea-compared-to-water-for-hydration.aspx
Small study I know .

I heard that Alcohol is genuinely dehydrating, but not caffeinated drinks. they irritate the blader but don't much dehydrate otherwise. The odds are that basically bits of her are not working well with the fluid intake she has, it's the age, sadly.

I'm sure tea counts, and for most people the requirement is 2 litres of water from all sources ie water in food also counts.

However if she is taking diuretis she will need more fluids than would otherwise be the case. Has she been given any indication of how much she should be drinking? She probably needs to treat water (or juice or whatever) almost as part of her medical regime. Does she take any tablets? Maybe she could get into the habit of a big glass with each tablet.

Is she fairly mobile? At 92 and on diuretics could she be limiting her fluids because it is an effort to go to the loo?

It might help her if she has a 500ml bottle or jug beside her and she sips her way down it then refills. Then she'll know how much she's drunk and how much she needs to do. It is hard work.

She's fairly mobile and no incontinence issues .

She has one of those sports top bottles of water next to her and sips from that . ( I refill it and other bottles next to her bed etc as she has very limited eyesight plus very little feeling and dexterity in her fingers )
She's also fond of pear juice which again she drinks from a bottle on the table next to her .

But she has very little appetite and she does regard drinking a large ( half a pint ) of liquid as filling her up and putting her off her food even more .

The doctor wants to increase her diuertics .
I get this is because her heart is failing but I can't figure out how it works with regard to her poor renal function .
It feels a bit to me like like whipping an exhausted horse .
Maybe more akin to doping an exhausted horse ?

I don't know about hard ,feels frankly impossible to me .

And we have to go back for more telling off next week .

How is she now?

Oh ,that's kind to ask .

Not too bad thanks . I'm trying to push the liquids all the time .
I've changed the pear juice for cranberry and raspberry - less fructrose .

Doc at hospital clinic decided not to increase diuertics because she was starting a weeks course of antibiotics . That's what he said .

More visits and clinics to attend .... it's hard to feel that we're included in what's going on ,just feels like my mum has tests .