Diabetes and Dehydration: Symptoms and Causes

If you’re living with diabetes, you know how important it is to maintain a healthy blood sugar (glucose) level.

If left unchecked, high blood sugar can damage blood vessels and nerves in your body. It can also cause complications like kidney failure, blindness, and cardiovascular disease.

But while medication, exercise, and a healthy diet can lower your blood sugar, it’s also important to stay hydrated. High blood sugar can reduce fluid levels in your body, which can lead to dehydration.

Dehydration and diabetes can go hand-in-hand. In fact, thirst and dry mouth — both signs of mild dehydration — are often the first indicators of diabetes. But, what’s the connection between diabetes and dehydration?

This connection has everything to do with how the body responds to high blood sugar.

Diabetes means that your body doesn’t make insulin or use insulin properly. Insulin is a hormone that allows your body’s cells to absorb sugar in your bloodstream, and then use that sugar for energy.

If your body doesn’t use insulin properly, sugar can accumulate in your bloodstream. When your blood sugar remains high for an extended period, your kidneys must work harder to filter and remove the excess glucose. This happens by means of urination.

It’s this increase in urination that leads to dehydration, especially if you don’t replace lost fluids.

Diabetes thirst

Excessive thirst is an initial symptom of diabetes, as well as a symptom of mild dehydration.

Diabetes thirst increases when your body loses too much water from urination caused by high blood sugar. Even if you drink often, you might still feel thirsty or dehydrated.

This is because your kidneys will continue to produce more urine to flush out excess glucose. This cycle continues as long as your blood sugar is too high.

Diabetic ketoacidosis

Diabetic ketoacidosis (DKA) is a complication of diabetes that occurs after prolonged high blood sugar, and is more common in type 1 diabetes.

If your cells can’t absorb sugar for energy, your body will start to burn fat for fuel. This process produces a type of acid called ketones, and too many ketones in your bloodstream can lead to serious complications.

This condition can cause your body to lose a large amount of fluids, which can send you into shock. Severe symptoms of diabetic ketoacidosis include:

  • dry skin
  • flushed face
  • headaches
  • muscle stiffness
  • vomiting
  • diabetic coma

Diabetes insipidus

Diabetes insipidus is an entirely different condition from diabetes mellitus, and can result from either the pituitary gland not making vasopressin correctly, or the kidneys being unable to respond to it. Vasopressin is an antidiuretic hormone, and causes the kidneys to be unable to retain water.

When this happens, your kidneys will excrete a large amount of urine, which can cause dehydration.


Keeping your blood sugar within a normal range helps your body maintain a healthy…

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