Why Am I Always Thirsty?

Medically Reviewed by Jennifer Robinson, MD on September 12, 2023
Written by Erica Petri
3 min read

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 refilling your cup without relief, it could signal another health problem.

Dehydration means your body doesn’t have enough water to carry out normal tasks, and thirst is the main symptom. It can happen for a lot of reasons, such as exercise, diarrhea, vomiting, and too much sweating.

Besides wanting water, other signs can include:

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

Thirst you can’t seem to quench, what doctors call polydipsia, is one symptom of diabetes. When you have this disease, 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:

 

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:

 

When your mouth feels very dry, it can make you 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 like cancer, diseases like Sjogren’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 means your body doesn’t have enough healthy red blood cells. Some people are born with it, while others get it later in life. There are a lot of things that can cause it, including diseases, a poor diet, or heavy bleeding.

Mild anemia probably won’t make you thirsty, but you might find yourself craving more water if the condition gets severe.

Other symptoms include:

 

Hypercalcemia means the calcium levels in your blood are above normal. Causes include overactive parathyroid glands (hyperparathyroidism), another illness (tuberculosis, sarcoidosis), and even cancer (lung, breast, kidney, multiple myeloma). Besides thirst, symptoms of hypercalcemia may include:

 

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.