On a hot summer day, or after a long workout, it’s normal to be really thirsty. After all, you’ve just lost a lot of water through sweat, so your body is telling you to replenish it ASAP. If you’re always thirsty, though, for no apparent reason, that’s not quite so normal.
As long as you’re drinking (and eating) water throughout the day, and making sure to hydrate during and after exercise, you shouldn’t ever feel excessively thirsty. If you are, it can be a sign of a few medical conditions—some simple, others a bit more serious.
Natasha Bhuyan, M.D., a family doctor at One Medical in Phoenix, Arizona, tells SELF that you should try to drink enough water throughout the day so that you never feel super thirsty. “When you get to the point that you’re thirsty, you’re already behind the ball,” she says. “The reality is we shouldn’t feel thirsty, and the reason why is we should stay ahead of water intake.” That means not waiting to drink water until your mouth feels like the Sahara, but rather, slowly sipping it throughout the day. You probably don’t ever have to worry that you’re drinking too much: Overhydrating is a medical possibility, and can come with serious side effects, but you’d have to try exceptionally hard to overpower your body’s way of dealing with excess water (e.g. peeing) and ignoring cues it’s sending you that it’s had its fill. “Our bodies are pretty good at regulating our intake,” Bhuyan adds.
If you experience that thirsty feeling more often than not, here are some potential reasons why.
- You’re simply not drinking enough, so you’re dehydrated.
“The main reason people feel thirsty is because they’re dehydrated, they’re not drinking enough water,” Bhuyan says. Simple enough. The standard recommendation is eight glasses of water a day—though it doesn’t have to all be from straight H2O; other liquids count, and there’s a lot of water content in your food, too. Some people have higher hydration needs than others, so even if you think you drink enough every day, you actually might not. “People who are regularly working out and exercising and those who live in dry climates should drink more water, too,” according to Bhuyan. Anytime you’re vomiting or have diarrhea, you’re losing fluids and should drink more to replace them (even if you’re not always thirsty right away). Any of these things can lead to mild dehydration, which can easily be fixed by just getting more fluids. (Extreme dehydration may warrant an ER visit.)
- You’re eating too much salt.
“Foods that are high in salt make people thirsty,” Bhuyan says. Our bodies need the right balance of sodium and water to function properly, so when salt intake is too high, we get thirsty so that we’ll reach for H2O to dilute our blood. This doesn’t just happen because you’re binging on pretzel rods—sodium is in a lot of the foods we eat, whether they’re blatantly covered in salt or not. If you’re eating a lot of salt, you may also feel super bloated—that’s because your body’s holding onto its little water content for dear life. Chugging will not only quench your thirst, but help you deflate, too.
- Your medications cause dry mouth.
Some drugs can cause dry mouth, which makes you feel thirsty. Two OTC medications to look out for: Dramamine (for motion sickness) and antihistamines for allergy relief, Bhuyan says. If you’re taking meds that come with these side effects, “Make sure to drink more water to make sure you’re staying ahead of your hydration status,” she suggests.
- You have diabetes.
Diabetes interrupts your body’s ability to break down and store sugar correctly, Bhuyan says. “So you get high sugar levels in the blood and often in the urine,” she says. “What sugar does is it draws out fluid and makes people pee more. It’s the body’s natural way of trying to pee out extra sugar,” she explains. Frequent thirst and urination are both signs of the disease. If you are actively drinking a lot of water and are still always thirsty, see a doctor to get your blood sugar tested. It’s quick and virtually painless.
- You have an autoimmune disease.
Sjogren’s syndrome is an autoimmune disease that affects the mucous membranes. The main symptoms are dry eyes and dry mouth, which can leave you feeling thirsty. With Sjogren’s, “your salivary glands don’t make enough saliva, so every time you eat food it feels like eating dry crackers,” Bhuyan says. If you’re constantly drinking to combat dry mouth, and you’re not taking any medications that may be causing it, Sjogren’s is a possibility.
- You have diabetes insipidus.
Contrary to what the name suggests, this isn’t the same as diabetes. Diabetes insipidus is a rare condition, caused by a hormonal imbalance, that impacts your salt and water metabolism and causes extreme thirst. “People with diabetes insipidus pee all the time even though they don’t have excess water, so it dehydrates them,” Bhuyan explains.