Thirst is your body’s way of telling you that it’s running low on water, which it needs to work well. It’s normal to feel thirsty when it’s hot or after you’ve powered through an intense workout.
But if you’re constantly sipping water without relief, it could signal another health problem.
Dehydration
Dehydration means your body doesn’t have enough water to carry out normal tasks, and thirst is the main symptom. It can happen for many reasons, such as exercise, diarrhea, vomiting, and too much sweating.
Besides wanting water, other signs can include:
- Dark-colored urine
- Not needing to pee as often
- Dry mouth
- Dry skin
- Feeling tired or lightheaded
- Headache
Kids who are dehydrated might also:
- Have few or no tears when they cry
- Have a dry, sticky mouth
- Go to the bathroom less or have fewer wet diapers
- Be cranky or sluggish
Diabetes
Thirst you can’t seem to quench, what doctors call polydipsia, is one symptom of diabetes. When you have diabetes, your body doesn’t make enough of the hormone insulin or doesn’t use it properly. It causes too much sugar (called glucose) to build up in your body.
Glucose in your urine draws in more water, so you pee more often. That leaves your body wanting to replace the fluid you’re losing.
Along with thirst and more visits to the restroom, other symptoms of diabetes include:
- Blurred vision
- Feeling very tired
- Hunger
- Cuts and bruises that are slow to heal
Diabetes Insipidus
Despite its name, this condition isn’t related to diabetes. It happens when your body doesn’t make enough of a hormone that helps your kidneys control the amount of water in your body. Excessive thirst is one of the major symptoms.
If you have diabetes insipidus, you may also have:
- Dehydration
- The urge to pee often
Dry Mouth
A dry mouth can make you feel very thirsty. Usually, it happens because the glands in your mouth make less saliva. You may get it because of medications you take, treatments for other conditions such as cancer, diseases like Sjögren’s syndrome, nerve damage in the head and neck, or tobacco use.
If your glands don't make enough saliva, you may have other symptoms, such as:
- Bad breath
- Change in taste
- Irritated gums
- Lipstick sticking to your teeth
- Thick, stringy saliva
- Trouble chewing
Anemia
Anemia means your body doesn’t have enough healthy red blood cells. Some people are born with it, while others get it later in life. A lot of things can cause it, including diseases, a poor diet, or heavy bleeding.
Mild anemia probably won’t make you thirsty, but if it gets severe, you might start craving more water.
Other symptoms include:
- Dizziness
- Fatigue and weakness
- Pale or yellowish skin
- Quick pulse
- Sweating
Hypercalcemia
Hypercalcemia means the calcium levels in your blood are above normal. Causes include overactive parathyroid glands (hyperparathyroidism), certain illnesses (such as tuberculosis or sarcoidosis), and even cancer (lung, breast, kidney, multiple myeloma). Besides thirst, symptoms of hypercalcemia may include:
- More frequent urination
- Stomach upset
- Nausea and vomiting
- Constipation
- Bone pain and muscle weakness
- Brain issues (such as confusion, fatigue, and depression)
- Heart issues (rare), such as racing pulse or skipped beats (arrhythmia)
Other Reasons You Might Be Thirsty
Other reasons you might be thirsty include:
- Eating spicy or salty foods
- Heavy bleeding
- Taking medicines (such as anticholinergics and diuretics) that cause excessive thirst as a side effect
- Psychogenic polydipsia, a mental condition that causes you to want to drink water even when your body doesn’t need it
- Hyperthyroidism (overactive thyroid)
Excessive Thirst in Pregnancy
Excessive thirst is a common symptom in many pregnant people and is usually not a cause for concern. You might also notice that you’re peeing more. However, having these symptoms could also mean you have high blood sugar, a condition called gestational diabetes. This diabetes happens only in pregnant people due to pregnancy-related body and hormone changes, such as weight gain. It usually causes no symptoms.
If you have gestational diabetes, your doctor may suggest lifestyle changes, such as eating healthier foods and being more active. They might also prescribe medications to help you manage your blood sugar levels. Following your treatment plan may help reduce excessive thirst and other symptoms.
How Can You Quench Your Thirst?
The answer depends on what is making you so thirsty. Drinking more water is a good place to start. But if you can’t satisfy your craving for it, talk with your doctor.
Whatever the cause, don’t just live with it. Most of the conditions that cause thirst are treatable.
When to Get Help for Excessive Thirst
Get help if you find that even after hydrating and eating water-rich foods, such as cucumber, you still feel thirsty soon after. See a doctor if you have other symptoms — such as peeing often, feeling tired and hungry frequently, and having slow-healing wounds — which may indicate health problems like diabetes.
Takeaways
For many people, feeling thirsty is just their body telling them it needs water. But if you continue to feel thirsty even after drinking water, it might be a symptom of a health condition such as diabetes, anemia, dry mouth, or hyperthyroidism. Excessive thirst may also be a side effect of your medication. See a doctor if you have excessive thirst that doesn’t go away even after you hydrate.
Excessive Thirst FAQs
What am I lacking if I'm always thirsty?
If you’re always thirsty, your body lacks enough fluid to work well. It could also mean your body has too much vitamin D.
Why am I always dehydrated even when I drink water?
Feeling dehydrated even after drinking water could mean you have an untreated health condition that causes excessive thirst, such as diabetes or anemia.
What illness causes constant dehydration?
Illnesses that cause constant dehydration include diabetes, dry mouth, anemia, hyperthyroidism, hypercalcemia, and psychogenic polydipsia.
What hormone causes excessive thirst?
If your body doesn’t make enough antidiuretic hormone or cannot use it well, you can experience excessive thirst.
What causes excessive thirst at night?
Not drinking enough water during the day can cause excessive thirst at night. You might also feel thirsty at night if you eat spicy or salty foods or drink alcohol before bed. Other triggers include being in a hot room or breathing through your mouth.