If you’ve been drinking the same amount of water as usual – be that 8 glasses a day or a few sips – but are feeling unusually dehydrated, the reason might be stranger than you’d think.

Lack of water can be caused by a huge number of reasons, many of which you might not be aware of. Here’s some of the more common ones to keep an eye out for…

1. Are you on your period?
Oestrogen and progesterone actually do have an influence on your body’s water stores. This usually isn’t an issue, but during your period the two hormones can fluctuate massively. This can leave you lacking in water, so if it’s your time of the month, try to fit in an extra glass of water each day.

2. Avoiding carbs?
A low-carb diet is a sure way to drop the pounds, but it can cause your water levels to plummet too. A lot of the weight loss on a carb-free diet is just down to loss of water – so once you go back to normal, the scales will move up again. Eating cooked rice, pasta and other carbs boiled in water is another sure source of H20, so once you stop, your body will notice the difference.

3. Stressed out?
Stress might seem like an unlikely cause of dehydration but the two do go hand in hand. Our kidneys are responsible for the production of the stress hormone cortisol, as well as the water regulation hormone aldosterone. When you’re stressed, your kidneys can tire out from producing so much cortisol, meaning they stop releasing normal levels of other hormones. A lack of aldosterone can quickly trigger dehydration. If you’re stressed, at least help your kidneys out a little by drinking extra water.

4. Not eating enough fruit and vegetables?
Piling half your plate with fresh fruit and veg at every meal means your body takes in almost 500ml extra water per day. So if you’re not getting your 5-a-day, this can in turn cause dehydration.

5. Working out regularly?
Sure, if you’re suffering through a hot yoga class you’ll be clinging to your bottle of water like it’s your best friend, but it’s important to drink lots of fluid even during moderate exercise. Any time you sweat, your body loses water. A good tip is to weigh yourself immediately before and after exercise. If there is any change in that short time span, it’s probably down to water loss – so drink an extra 500 ml of water for every pound of weight difference.