Could my scales be causing my weight to seemingly yo yo?

[TyrionLannistersShadow]

I've had my current scales (glass electronic ones, cheap enough at the time) for years , maybe the best part of 10 years? Anyway I've lost a lot of weight over the past year and am working on maintaining it/losing a bit more, but my scales show I'm putting on and losing up to 1kg or 1.5kg a day? So for example yesterday my scales said 72.1 and it's 73.1 today even though I'm eating the same as always, tomorrow I might be 0.5kg down ( or up!) again? Is it possible for digital scales to act up sporadically or would they be consistently wrong if they needed to be replaced? Also I've always stored them on their side out of the way (tiny bathroom!) but read somewhere recently that you're supposed to leave them flat all the time and in the one place?
Now before anyone says you should only weigh weekly , I know that's what's recommended but I've weighed daily for the past year and never had this issue before, plus I just prefer to keep a daily eye on it. 1 to 1.5kg (2lbs to 3.5lbs approx) just seems a lot to jump up or down in a day and it's all the time so not related to my cycle or anything. Is it worth just replacing my scales, do they have a time limit?

Well 0.5kg weight fluctuation is possible even if the scales are accurate as you do gain and lose weight slightly over the course of the day depending on water retention and poo (TMI sorry!). But yes, I find digital scales get more and more unreliable as they get older and if you've had them for years they probably aren't completely accurate anymore - try changing the battery and also make sure they are on a completely flat surface when you use them, and if they are stored on their side make sure they have time to calibrate properly when you turn them on. Or just buy a new pair if they were only cheapies?

I decided to buy a new scales so we will see how it goes!

I mean you can lose 1.5kg going to the toilet so I wouldn't worry about it. I weigh in stone and pounds, but can go up or down between 3-7lbs depending on what I eat, and whether I'm on my period (bloated) or not, and have been told that's within normal realms.

They do say the first half a stone is "water weight" which does tell you that 0.5-1.5kg would be easy to lose or gain in water weight due to salt intake/food intake/toilet habits/losing sweat/gaining bloat etc.