Diabetes and polydipsia (extreme thirst)

Polydipsia, a persistent feeling of extreme thirst, is often associated with diabetes.

While extreme thirst is a well-known symptom of undiagnosed diabetes, polydipsia can occur in people with existing diabetes for a number of reasons.

In this article, we’ll explore the link between diabetes and polydipsia, and what you can do about it if you struggle with the condition.

What is polydipsia?

Polydipsia is the medical term for extreme or excessive thirst.

Thirst is a normal feeling that tells you that your fluid balance is out of order and that you should drink something. But persistent thirst, especially if you’re already drinking plenty of fluids, is not normal and could be a sign of illness.

If polydipsia leads someone to drink excessive amounts of fluids to quench their thirst, it can also result in polyuria, the medical term for when a person produces excessive amounts of urine.

But how much fluid is considered polydipsia? Generally, drinking 5 or 6 liters of fluids a day and feeling thirsty all the time would be considered polydipsia.


What can cause polydipsia and extreme thirst?
Polydipsia is a symptom of several conditions, including:

Undiagnosed diabetes.  Type 1 diabetes, type 2 diabetes, gestational diabetes and prediabetes can cause polydipsia
High blood sugar in a person already diagnosed with diabetes
Diabetes insipidus, a rare disease unrelated to diabetes.  Diabetes insipidus does not affect blood sugar but instead causes polydipsia and polyuria because the kidneys do not concentrate urine properly
Acute dehydration
Certain behavioral health conditions, including some anxiety disorders
Certain serious kidney injuries or diseases, including polycystic kidney disease, liver disease, and heart failure
Serious infections, including sepsis
Electrolyte imbalances, especially hypokalaemia (low levels of potassium in the blood)

In addition to diagnosable medical conditions, transient extreme thirst can also be caused by fluid loss through diarrhea or vomiting, or by sweating, especially with a high temperature.
Many people will also experience it due to dietary factors, such as consuming excessive amounts of alcohol or caffeine, or eating very salty foods.
Pregnancy and some prescription drugs can also cause extreme thirst.
Some people experience polydipsia at night if their bedroom temperature is too high or due to nasal congestion or a condition that causes them to breathe through their mouths instead of through their noses while sleeping.
Many factors and conditions can lead to excessive thirst, but if thirst persists for several days and drinking enough fluids doesn’t help, it’s a good idea to talk to your doctor or healthcare provider.

Diabetes and polydipsia
Excessive thirst is one of the main warning signs of diabetes and is often one of the first symptoms a person notices before making a diagnosis. 
For this reason, unexplained polydipsia should not be ignored.
The reason diabetes and thirst are so linked is that hyperglycemia (high blood sugar) often makes you feel thirsty.
When someone’s blood sugar is high, their kidneys have to do extra work to absorb the excess sugar circulating in the blood.  Much of this extra sugar is also flushed out of the body in the urine.  The body needs to draw fluid from the organs and tissues to accomplish this, but doing so disrupts the body’s normal fluid balance, leaving the person dehydrated. 
Humans, like most other living organisms, must maintain fluid levels within a very narrow range to stay healthy.  When someone becomes dehydrated because their tissues give up excess fluid to help flush out excess sugar, the brain senses the imbalance and triggers a feeling of thirst.
If someone’s blood sugar remains high, their kidneys will continue to try to flush out excess sugar, meaning dehydration will continue, fluid levels will not return to normal, and they will likely continue to experience extreme thirst.
However, with the help of a doctor, blood sugar levels can be managed, which usually gives way to excessive thirst quite quickly.
Depending on the type of diabetes a person has, doctors and other health care providers prescribe a combination of medications (such as injectable insulin or oral metformin), as well as suggested guidelines for diet, exercise, and behavior. 
A fingerstick manual blood sugar test or continuous glucose meter may also be prescribed to help track blood sugar levels over time and help a person with diabetes adjust their medications or diet to avoid high or low blood sugar.
You will also likely be ordered a hemoglobin A1C blood test to track your average blood sugar levels over a three-month period.
Together, these tools can help people with diabetes avoid high blood sugar and symptoms such as the common polydipsia.  
Once their blood sugar levels are back in the normal range, most people with diabetes will notice that their excessive thirst subsides quickly. 

Is polydipsia a symptom of diabetic ketoacidosis?
Higher than normal blood sugar levels (hyperglycemia) can cause polydipsia.  Prolonged or very high blood sugar levels can lead to diabetic ketoacidosis (DKA).
Excessive thirst and excessive urination are common early symptoms of diabetic ketoacidosis. 
If you’ve been diagnosed with diabetes, it’s important to keep your blood sugar under control and look out for symptoms of DKA, including unquenchable or excessive thirst and needing to urinate more than usual. 
If you think you are in DKA, it’s important to seek medical attention right away.

How can you deal with excessive thirst if you have diabetes?
For most people, the key to resolving polydipsia is getting their blood sugar levels back into the normal range.
To stop feeling excessively thirsty if you have diabetes, it’s important to both drink enough fluids to stay hydrated and to safely bring your blood sugar back into the normal range, which is around 80 to 130 mg/dL, unless you’ve eaten a lot Lately.
When you drink fluids to stay hydrated, it’s best to avoid drinks high in carbohydrates or added sugar (unless your blood sugar is low).
Preventing blood sugar levels from remaining high for a long time and safely returning them to the normal range when they are high is the key to stopping you from feeling excessively thirsty due to diabetes.
If your blood sugar levels are normal and excessive thirst persists even after drinking plenty of fluids, you may want to talk to your doctor or health care professional.

Application
Polydipsia, or excessive thirst, is something that people with diabetes often experience before diagnosis, but it can also occur after diagnosis if blood sugar levels are high and if the person is suffering from diabetic ketoacidosis.
Dehydration, fluid imbalances, and electrolyte imbalances can all contribute to polydipsia, all of which can be the result of blood sugar levels that are above normal.
Staying hydrated by drinking plenty of fluids and carefully controlling your blood sugar to prevent severe or long-term high blood sugar are the best steps to take to address polydipsia.
Many conditions and other factors can cause excessive thirst, but if this feeling persists for several days and drinking fluids and keeping your blood sugar levels in check doesn’t help, it’s worth talking to your doctor or health care professional right away.