Excessive thirst, or polydipsia, can be a symptom of diabetes. If someone is experiencing excessive thirst and frequent urination, they should see a doctor.

In this article, we describe the connection between excessive thirst and diabetes, as well as the different types of diabetes that can cause this symptom.

a woman with diabetes drinking water as she has increase thirstShare on Pinterest
A person with diabetes may experience excessive thirst.

One symptom of diabetes is feeling unusually thirsty.

Anyone who is experiencing the following symptoms should see a doctor:

  • feeling thirstier than usual
  • still feeling thirsty after drinking
  • dry mouth
  • urinating more than usual, or polyuria

Age, lifestyle, and activity levels can contribute to how much a person drinks.

According to the Centers for Disease Control and Prevention (CDC), there are currently no guidelines about how much water a person should drink each day.

In 2004, the Institute of Medicine estimated an adequate daily water intake as 3.7 liters for males and 2.7 liters for females. These amounts included water from all the drinks and foods in a person’s diet.

According to the National Health and Nutrition Examination Survey, 2009–2012, males in the United States tend to consume 3.46 liters of water per day, while females in the country typically consume 2.74 liters per day. These figures also included water from all dietary sources.

However, from day to day, a person may feel more or less thirsty for a variety of reasons. Spending time in the sun or being especially active, for example, can contribute to thirst.

Different types of diabetes can cause excessive thirst.

Diabetes mellitus

The term “diabetes mellitus” includes diabetes types 1 and 2.

A person with type 1 diabetes is unable to produce insulin.

Someone with type 2 diabetes is able to produce insulin, but their body is unable to use it effectively to help glucose enter cells.

In either case, glucose from digested food remains in the bloodstream.

As the authors of a 2014 article note, the kidneys excrete some excess glucose through urine. As the glucose draws water into the urine, the body loses more fluid than it should. This results in the person becoming extra thirsty.

Gestational diabetes

Gestational diabetes occurs during pregnancy.

Just as in a person with diabetes mellitus, in a woman with gestational diabetes, insulin resistance can lead to hyperglycemia.

For the reasons that we describe in the section above, this can lead to an increased need to urinate and excessive thirst.

Diabetes insipidus

Diabetes insipidus is a rare condition that involves the kidneys passing an unusually high amount of urine, which is diluted and odorless.

Typically, the kidneys pass about 1–2 quarts of urine a day. In someone with diabetes insipidus, the kidneys can pass 3–20 quarts a day. This results in the person being excessively thirsty.

Unlike a person with diabetes mellitus, someone with diabetes insipidus has normal blood glucose levels. However, their kidneys are unable to balance the amount of fluid in the body.

This can happen for a number of reasons, including:

  • damage to the hypothalamus or pituitary gland, two small parts of the brain
  • inherited genetic mutations
  • an abnormality in the thirst mechanism
  • transient gestational diabetes insipidus, which occurs during pregnancy

The factors above can disrupt the function of the hormone vasopressin. This hormone works with the brain and kidneys to help regulate fluids in the body.

Some other symptoms of diabetes include:

  • tingling or numbness in the hands or feet
  • blurred vision
  • fatigue
  • unexplained weight loss
  • sores that do not heal

The right approach to diabetes depends on the type, and a doctor can recommend the best course of action.

Type 1 diabetes

People with type 1 diabetes need to take insulin.

A doctor may recommend:

  • self-injecting with a syringe
  • using an insulin pen
  • using a jet injector, which sends a fine spray of insulin into the skin without a needle
  • wearing a pump device that delivers steady doses
  • using an inhaler that delivers powdered insulin to the lungs

A person with type 1 diabetes also monitors their blood glucose levels with a device called a meter.

They use a lancet to take a drop of blood and apply it to a test strip. The test results can help the person make decisions about their diet and medication routine.

Type 2 diabetes

Some people with type 2 diabetes are able to manage the condition through diet and exercise.

Others also benefit from taking medication, such as metformin (Glucophage), which comes as tablets or a liquid.

Gestational diabetes

The doctor will focus on keeping blood glucose levels in check. They may recommend special meal plans, scheduled activities, insulin injections, or a combination.

A woman with this condition may need to monitor her blood glucose levels every day throughout the pregnancy.

Diabetes insipidus

For someone with diabetes insipidus, the primary treatment is drinking enough liquid to prevent dehydration.

A doctor may refer the person to a specialist for testing or treatment. This might be a nephrologist, who specializes in kidney-related conditions, or an endocrinologist, who specializes in hormone disorders.

If a person has symptoms of diabetes, a doctor may perform blood tests to make a diagnosis.

A doctor may also want to test infants or young adults with family histories of type 1 diabetes, as well as people with risk factors for diabetes, including overweight or obesity.

Healthcare professionals should test pregnant women for gestational diabetes between 24 and 28 weeks of gestation.

To check for transient diabetes insipidus in pregnancy, a doctor may perform a water deprivation test.

To help manage diabetes or better understand the course of the disease, a person can:

Overall, having a healthful diet and lifestyle can help prevent some forms of diabetes. This can involve:

  • having a whole-foods diet
  • limiting the intake of processed foods
  • avoiding foods and drinks that contain added sugars
  • increasing awareness of portion size and calorie intake
  • limiting alcohol consumption
  • being more physically active
  • maintaining a healthful weight

If someone is excessively thirsty and has dry mouth, they should see a doctor. A person should also see a doctor if they are urinating more often than usual.

People with diabetes should report any new symptoms or unusual blood glucose readings to their doctor or another member of their diabetes management team.

Because diabetes can cause further health issues, it is important for people with the disease to routinely visit a doctor.

The doctor may want to check the person’s:

  • blood pressure
  • foot health
  • weight
  • diet plan

For people with diabetes insipidus, the main complication is dehydration. Symptoms of dehydration include:

  • thirst
  • dry skin
  • fatigue
  • sluggishness
  • nausea
  • confusion
  • dizziness

A person with any of these symptoms should receive medical attention immediately.

Anyone who experiences excessive thirst should see a doctor, who may check for diabetes. A person may also be dealing with dry mouth and frequent urination.

People with diabetes need to manage the condition carefully and report any new symptoms to their doctor or diabetes team.

A family history of diabetes or ongoing health issues, such as obesity, can increase the risk of developing the disease. A person can often limit their risk by maintaining a healthful diet and lifestyle.