7 morning signs that can accompany high or poorly controlled blood sugar
These symptoms aren’t proof that blood sugar is high—many have other causes. The most reliable way to know is to check your glucose and, when appropriate, get an A1C test.
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Waking very thirsty — excessive thirst can occur when glucose levels are elevated.
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Frequent urination, especially overnight — high glucose can cause the kidneys to excrete more glucose and water.
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Dry mouth — can accompany dehydration from increased urination.
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Morning headaches — can occur for several reasons, including dehydration or overnight glucose fluctuations.
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Blurred vision — changing glucose levels can temporarily affect the eye’s focusing ability.
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Unusual fatigue or weakness — persistent high glucose can contribute to tiredness.
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Nausea or feeling unwell — particularly concerning when accompanied by very high glucose, abdominal pain, rapid/deep breathing, or confusion.
When it’s urgent
If someone with diabetes has very high glucose together with vomiting, abdominal pain, rapid/deep breathing, severe drowsiness, confusion, or fruity-smelling breath, they may have diabetic ketoacidosis (DKA), which requires urgent medical care.
If you’re concerned about your morning readings, keeping a record of fasting glucose and symptoms for several days can provide useful information for a clinician.
