Another morning clue that can sometimes be associated with high blood sugar is frequent urination, also known medically as polyuria when urine output is excessive.
You may find yourself waking up multiple times during the night to use the bathroom. Or perhaps you sleep through most of the night but immediately need to urinate after getting out of bed—and then continue making frequent bathroom trips throughout the morning.
High blood glucose can contribute to increased urination because the kidneys filter glucose from the blood. When glucose levels exceed the kidneys' ability to reabsorb it efficiently, glucose remains in the urine.
Water follows glucose.
As a result, more urine is produced.
This process can lead to the familiar combination of frequent urination and increased thirst.
Again, however, this symptom is not specific to diabetes.
You may urinate frequently because you drink large amounts of water before bed. Caffeine can increase urinary frequency in some people. Alcohol can do the same. Certain medications, particularly diuretics, are specifically designed to increase urine production.
An enlarged prostate can cause urinary symptoms in men. Urinary tract infections can cause urgency and frequent urination, often with burning or discomfort. Pregnancy, bladder conditions, and other medical problems can also change urination patterns.
Nighttime urination can increase with age as well.
So how should you think about the possibility of blood sugar?
Look for a change from your normal pattern.
If you suddenly begin waking two, three, or four times per night to urinate without an obvious explanation—and you are also unusually thirsty or tired—mention the pattern to a healthcare professional.
Do not assume it means diabetes, but don't dismiss it either.
Persistent excessive urination can contribute to dehydration and disrupted sleep. And disrupted sleep itself can worsen daytime fatigue, creating a cycle in which several symptoms overlap.
There is also a more urgent situation to recognize.
If frequent urination occurs alongside severe thirst, vomiting, abdominal pain, deep or rapid breathing, confusion, marked weakness, or a fruity-smelling breath, seek urgent medical attention. Those symptoms can be associated with diabetic ketoacidosis, a potentially life-threatening metabolic emergency that is particularly associated with type 1 diabetes but can occur in other circumstances.
Most people with frequent urination will not have this emergency.
Still, knowing the warning signs matters.
Your bathroom habits can sometimes provide one clue among many. The key is to consider frequency, severity, duration, and accompanying symptoms, rather than treating one symptom as a diagnosis.