This Is Why You're Always So Thirsty Before Bed

The human body is a complex thing, which is why every time you're about to get into bed you're suddenly desperately and urgently thirsty for water. While it can feel like your body is out to deliberately sabotage your sleep, research has found that the brain actually stimulates thirst neurons regardless of whether you are dehydrated.

A 2016 study by McGill University in Canada found that the brain's biological clock stimulates thirst in the hours before sleep. According to Dr ikola Djordjevic, a GP and medical advisor at Whatasleep, it's to do with our circadian rhythm and the production of hormones that ease us into sleep.

Speaking to Popsugar, Dr Djordjevic explained that our circadian rhythm calibrates the production of hormones related to the position of the sun. "In the evening, we produce melatonin, which not only makes our mind sleepy, but also triggers the sleeping state of cells in which they repair and regenerate," she said. "Our body knows that hours without hydration are ahead, and it recharges our fluid supply, hence, the increased thirst at night."

Unsurprisingly, drinking so much water so late at night can lead to inconvenient bathroom breaks and interrupted sleep, meaning this late-night thirst phenomenon can be a real problem for overall health and wellbeing.

If it's just our body clock doing what it's meant to, is there anything we can do to prevent the sudden need to inhale a full two litres of water when we're supposed to be going to sleep? Doctors believe there are a few factors at play that can be addressed.

Factor #1: Salty food

The good news is that our biology isn't the only culprit for this bedtime thirst phenomenon. Dr Jesse P Houghton of the Southern Ohio Medical Centre explained to Popsugar that our lifestyle choices also play a role. "We actually have a 'thirst centre' in our brains that make us feel thirsty when our serum sodium level increases, such as when consuming salty food," he said.

Salty food can deprive the cells in our body of water, sending a chemical message to the brain asking for more water. Cutting down on salt can prevent those cells from becoming dehydrated.

Factor #2: Not enough water

It sounds like bad news, but realising you can help avoid bedtime thirst is definitely good news. Failing to stay sufficiently hydrated throughout the day will mean we are even thirstier than we would otherwise be at night. Drinking enough water throughout the day not only helps to avoid desert-level thirst at night but also works to aid digestion, improve brain function and generally detoxify our internal systems.

"The fact is that every cell in the human body needs water to function optimally," explained clinical professor of medicine at Wayne State University of Medicine, Dr Joel Kahn. "It's good practice to drink water throughout the day, as doing so provides a wide range of benefits, such as proper detoxification, better energy and digestion, and even improved brain function."

There are other elements that can increase thirst, such as certain medications or medical conditions, as well as extreme exercise and alcohol consumption. So, if making adjustments to your food and water intake during the day doesn't seem to be working, be sure to consult your doctor.

Always seek the guidance of your doctor or other qualified health professional with any questions you may have regarding your health or a medical condition.

Enjoyed this? What Happens to Your Body When You Drink 2L of Water a Day.