Chronic high blood sugar, or hyperglycemia, is the culprit behind a laundry list of diabetes complications, and it’s a daily struggle to keep blood sugar levels within normal range. But blood sugar can drop or spike without warning, and that’s when people with diabetes face an immediate danger: diabetic coma.
High blood sugar happens when there is too much glucose in the blood and not enough insulin to get it into the cells. If the body’s cells can’t get glucose to use for energy, they start to burn only fat as fuel. The fat-burning process produces ketones, and without insulin to regulate that process, ketones can build up and send someone into ketoacidosis, a life-threatening condition. High blood sugar can turn into ketoacidosis if not corrected.
It’s important to know the signs of a blood sugar spike so that someone can correct it, or get help, before things get too dangerous. Here are the 11 warning signs of high blood sugar:
If you didn’t just finish a workout or race up a flight of stairs and your breath is shallow, or it feels hard to get enough air, it could be a sign of low blood sugar. If there’s not a clear reason you’re short of breath, check your blood sugar.
2. Rapid heart beat
We don’t always notice our heart rates, but this is something to check if you feel “off” in other ways. Try feeling your pulse by placing two fingers against the side your neck under your jaw (or use a heart rate app or a fitness tracker) and see if you’re unusually fast. Can’t explain it? It could be your blood sugar.
3. Sweet- or Fruity-Smelling Breath
When your body starts burning fat, the ketones build up and produce a smell strong enough to be detected by the human nose. But this “sweet” smell isn’t a good smell—it’s often compared to rotting fruit or nail polish remover. It’s a sign of ketoacidosis, and you need to check for ketones and seek emergency medical attention if you’re not able to bring your levels back to normal.
4. Blurred vision
If your vision is fuzzy and it’s not because your glasses are dirty, it could be high blood sugar.
Confusion and disorientation can also be a sign of low blood sugar, and both are dangerous, so it’s important to check right away if you’re having trouble concentrating or thinking clearly. Confusion can be a sign of ketoacidosis.
6. Nausea or vomiting
You should check your blood sugar levels more often when you’re sick since illness can throw your blood sugar levels out of whack. But vomiting and nausea can also be a sign of ketoacidosis.
7. Extreme thirst
You get thirsty when your blood sugar is high because your body needs water to flush out your system, and more water can help lower blood sugar in the short-term. But it can also cause symptom number nine…
8. Frequent urination/glucose in urine
Having to pee seemingly all the time is often a first indicator of diabetes and can be a constantly nagging symptom. It’s another way the body tries to flush out excess glucose, as well as ketones if they’re present. Glucose in the urine is a sure sign of high blood sugar—diabetes used to be diagnosed by tasting someone’s urine.
Small amounts of ketones in your urine can be normal, but higher amounts are dangerous. If you have diabetes, talk with your doctor about what levels should concern you so that you’re ready when a blood sugar spike hits.
9. Dry or parched mouth
Your body tries to flush itself when blood sugar goes high, so any excess water that might have been used to keep your lips moist and your saliva flowing may be pulled away to create more urine. A severe dry mouth can be a sign of ketoacidosis.
If your body is not able to get glucose to your cells, then you’re going to feel drained of energy. If the problem is not corrected, you could go into a diabetic coma. Unusual fatigue, especially when combined with any of the other symptoms, is definitely a sign you should check your blood sugar. If the fatigue is extreme, get help so that you’re not alone in case of emergency.
11. Stomach/abdominal pain
Abdominal pain could be a sign of ketoacidosis. Check your blood sugar, or if the pain is severe, get to the doctor.
Checking for ketones
The American Diabetes Association recommends checking your urine for ketones if your blood sugar is above 240mg/dL. Symptoms of high blood sugar generally start once blood sugar is over 250mg/dL and progress as glucose rises. Talk to your doctor or diabetes educator about safe levels for you and what to do if your blood sugar goes high or you find ketones. It’s best to have a plan beforehand so that you know exactly what to do if your blood sugar spikes.
Katie Taylor started writing in 5th grade and hasn't stopped since. Her favorite place to pen a phrase is in front of her fireplace with a cup of tea, but she's been known to write in parking lots on the backs of old receipts if necessary. She and her husband live cozily in the Pacific Northwest enjoying rainy days and Netflix.