Polydipsia is a medical term that means excessive thirst. It's normal to be thirsty sometimes. You may have worked up a sweat, and your body is telling you it’s time to rehydrate. But if you feel thirsty all the time, even after drinking a lot of fluids, you may have a more serious health condition such as diabetes mellitus or diabetes insipidus.


What is polydipsia?

Polydipsia is the medical definition of excessive thirst. Excess thirst is an abnormal urge to drink fluids at all times. It’s a reaction to fluid loss in your body. Dry mouth (xerostomia) and the urge to pee often (frequent urination) may go along with it.

Drinking adequate amounts of water is very important because your body needs to stay hydrated to function properly. Everyone gets thirsty from time to time. But with polydipsia, your thirst may last for days, weeks or months. No matter how much you drink, you can never seem to quench your thirst.

If you feel thirsty all the time, or if your extreme thirst has increased or continues after you drink, it may be a sign of diabetes or another serious health condition.


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Possible Causes

What causes excessive thirst?

Your body needs a certain amount of water to function properly. If you’re feeling thirsty, you may just need to drink more water. Your body is reacting to lost fluids. Feelings of thirst may be due to:

But excessive thirst may be a sign of certain health conditions, such as diabetes mellitus. Having higher than normal blood sugar levels (hyperglycemia) can cause polydipsia. Hyperglycemia is one of the “big three” signs of diabetes mellitus.

If you have excessive thirst and urination, but you don’t have diabetes mellitus, you may have one of the following conditions:

  • Diabetes insipidus: Although they share a name, diabetes insipidus is unrelated to diabetes mellitus. Diabetes insipidus affects your kidneys and the glands and hormones that interact with them. This condition can result in your body producing large amounts of urine.
  • Loss of bodily fluids from your bloodstream into your tissues:This can result from medical conditions such as burns, sepsis, kidney failure, liver failure or heart failure.
  • Dehydration: If you don’t drink enough water over an extended period, your body can become dehydrated.
  • Psychogenic polydipsia: Some psychiatric and mental health disorders, such as anxiety and schizophrenia, can result in compulsive water drinking.
  • Low blood potassium (hypokalemia): Hypokalemia is a condition that can occur when you don’t have enough potassium in your blood.
  • Cystic disease: Cystic disease is a group of conditions in which cysts develop on or around your kidneys.

What’s causing my excessive thirst at night?

One of the most common reasons for waking up thirsty is you didn’t drink enough water during the day. Your body needs a certain amount of water for your salivary glands to produce enough spit (saliva). If your salivary glands don’t produce enough saliva, it can result in dry mouth. Other potential causes of extreme thirst at night include:

  • Medications you’re taking.
  • What you eat and drink before bedtime.
  • Drinking alcohol before going to bed.
  • The temperature in your bedroom.
  • Mouth breathing.
  • Underlying health conditions.


Care and Treatment

What can I do at home to treat polydipsia?

If you’re thirsty, your body is trying to signal that you need to replace water loss. The best way to treat this condition at home is to drink plenty of liquids. But if your excessive thirst continues, you should get in to see a healthcare provider who can determine the cause and recommend the appropriate treatment.

How can polydipsia be prevented?

Depending on the cause of your condition, you may be able to prevent excessive thirst by drinking more water and other fluids. Avoid drinking caffeine and alcohol.

If you have diabetes and have access to blood glucose testing equipment, you may want to test your blood sugar levels when you’re thirsty. Testing your blood sugar levels can help you determine if your blood sugar levels are too high.


When To Call the Doctor

When should polydipsia be treated by a healthcare provider?

If you have excessive thirst along with the following symptoms, you should see a healthcare provider:

  • Drinking lots of fluids hasn’t quenched your thirst after several days.
  • Frequent urination.
  • Excessive urination (polyuria).
  • Blurry vision.
  • Fatigue.
  • Excessive hunger (polyphagia).

Your provider can help determine what’s causing your polydipsia. They’ll ask you about your symptoms and perform a physical exam. Questions they may ask include:

  • How long have you been experiencing excessive thirst?
  • Did polydipsia develop suddenly or slowly?
  • Does your thirst change throughout the day or stay the same?
  • Have you recently changed your diet?
  • Has your appetite increased?
  • Have you had any unexplained weight loss or weight gain?
  • Has your physical activity level changed?
  • Have you had any recent burns or other injuries?
  • Are you sweating a lot?
  • How often are you urinating?
  • How much urine are you producing?

Your provider may also request several tests to help determine the cause of your polydipsia. These tests may include:

How will a healthcare provider treat polydipsia?

Based on your exam and blood tests, your healthcare provider will recommend treatment for the underlying condition causing polydipsia.

If tests show you have diabetes mellitus, they’ll recommend treatments to help manage your blood sugar levels. Treatment for diabetes insipidus may include drinking fluids to prevent dehydration. Your provider may refer you to a specialist for more specific treatments.

If your medications are causing polydipsia, your provider may adjust your dosage or change your prescription. Treatment for psychogenic polydipsia may include counseling to help you become more aware of your water consumption.

A note from Cleveland Clinic

It's normal to be thirsty sometimes. Your body may just be telling you it’s time to hydrate. But if you constantly feel thirsty even after drinking a lot of fluids, you may have a more serious health condition. See your healthcare provider to find out what's causing your excessive thirst. They can help determine treatment for whatever’s causing your polydipsia.

Medically Reviewed

Last reviewed on 08/24/2022.

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