Why You're So Thirsty & What To Do About It

While you may never be able to explain your overwhelming thirst for, say, the priest in Fleabag or Kristen Stewart, when it comes to the actual physiological sensation of thirst, usually there's a logical explanation for it. And it's important to be aware of this common symptom, because sometimes excessive thirst can be a sign of an underlying health condition.

So, how do you know if your thirst levels are considered "excessive"? It's normal to feel like you need to drink about a litre and a half of water per day, says Rocio Salas-Whalen, MD, an endocrinologist and clinical instructor in the department of medicine at NYU Langone Hospital. "Anything above that, if it’s consistently, then we can say somebody is excessively thirsty," she says. "And it should go along with excessively urinating, too."

If you're drinking more than two litres of water a day, it's be wise to talk to your doctor or healthcare provider, so they can help pinpoint the cause. Here's what it could mean if you are excessively thirsty all of the time:

This might sound pretty duh, but many times, excessive thirst is a consequence of dehydration, Dr. Salas-Whalen says. Dehydration is caused when you either lose too much fluid, don't drink enough fluid, or a combination of both. The key is figuring out why you're dehydrated, and how long you've felt this way. If you've been sweating a lot or exercising in intense heat, it might take a bit of fluid and electrolytes for you to get fully hydrated again. But chronic dehydration, on the other hand, can point to more serious health conditions.

One of the earliest and most common signs of diabetes is feeling like you need to drink constantly but can't keep up with your thirst, Dr. Salas-Whalen says. This is because people with diabetes typically have high levels of glucose in their blood. Usually, the kidneys would just flush out any excess of chemical protein byproducts in the blood. "But when the sugar goes up too high, at a point, the kidney can't keep up with that," she says. Sugar also pulls water from tissues, "so the person becomes very dehydrated and that triggers excessive thirst throughout the day," she says.

There are some psychological factors that make people want to drink more water, sometimes inexplicably, Dr. Salas Whalen says. For example, there's a psychiatric condition called psychogenic polydipsia, which can lead to compulsive water drinking. "It's not the body or dehydration asking you for water, it's just psychological," she says. We know that polydipsia tends to be associated with other psychiatric conditions such as depression, bipolar disorder, and schizophrenia.