High blood sugar is part of a life with diabetes, whether it’s type 1, type 2, LADA, gestational diabetes, even the more rare forms of the disease. But sometimes, hyperglycemia can seem unexplainable, persistent, and stubborn.
This article will outline the reasons why you may be experiencing high blood sugar, and what you can do about it.
What Exactly Happens When Blood Sugar Is High?
High blood sugar, by definition, is when there’s too much glucose in the blood and not enough insulin to help the cells digest it. That extra glucose floating around in the bloodstream is what brings about symptoms of frequent urination, fatigue, brain fog, headache, body ache. In severe cases, it can lead to diabetic ketoacidosis (DKA).
But even when you’ve done everything “right,” like counting carbohydrates and taking your medications, your blood sugar may rise and stay annoyingly (or dangerously) high. These are the top reasons why you may be experiencing unexplainable hyperglycemia.
Ever wonder why when you’re stressed about work or school your blood stays high? That’s because the release of natural hormones in your body, like adrenaline and cortisol, spike when you’re stressed, leading to insulin resistance, and in people with existing diabetes, high blood sugars. Whether you’re prepping for a big test, selling your home, hustling for that promotion at work, or fighting with your spouse, stress can send your blood sugars skyrocketing.
Dawn Phenomenon describes the high blood sugars and insulin resistance people experience in the morning, usually between 2 a.m. and 8 a.m.
The phenomenon is natural: late overnight, the body releases a surge of hormones in preparation for the new day. These hormones can trigger the liver to dump glucose into the bloodstream. In people with diabetes, the body cannot produce a healthy insulin response, and therefore blood glucose levels spike up.
Many people with diabetes require more insulin during those hours, maybe even twice as much, to counteract this age-old hormonal effect.
A different, less common (but more dangerous) phenomenon may also explain morning blood sugar highs: Somogyi effect.
When people with diabetes are under the weather (or fighting off an infection), their blood sugars tend to be much higher than normal, and they become much more insulin-resistant.
This can sometimes result in needing 75% (or more!) of your average daily insulin requirements. Make sure you’re staying hydrated, monitoring for ketones, and taking as much insulin as you need to keep your blood sugars in range.
If you cannot control your blood sugars during illness – especially if you’re having trouble eating or drinking – it’s very important to get in touch with your doctor.
You’re Eating Too Many Carbs
Let’s face it: carbohydrates spike blood sugar. It’s something that people with diabetes need to think about nearly every time they eat.
Test your blood sugar frequently to see how your own body responds to different foods. Some people may find that they can comfortably eat fresh fruit, but not added sugars or white rice. Some may find something completely different.
And if you use insulin before meals, you probably already know that carbohydrate counting can be an inexact science. The more carbs you eat, the more insulin you need to take, and the more difficult it is to deliver that perfectly dosed and perfectly timed pre-bolus.
Even a little carbohydrate restriction is likely to help reduce the frequency and intensity of blood sugar highs.
You’re Eating Hidden Carbs
Ever order a salad at a restaurant, thinking it will be a nice, low-carbohydrate option, only to experience debilitating high blood sugars for hours on end afterward? There are many deceiving foods that we think are low-carb, but are anything but.
Sugar and starches hide in many foods where you wouldn’t expect to find them, especially at restaurants and among the processed foods in the grocery store. Some examples of foods that seem “healthy” but can cause a blood sugar nightmare include:
- Salads with sweet dressings and croutons or other toppings (or salad in a bread bowl)
- Smoothies (especially fruit smoothies)
- Fruit juice
- Foods labeled “gluten-free”
- Flavored yogurts
- Fat-free ice cream
- Restaurant foods (especially due to extreme portion sizes)
“Healthy” does not necessarily mean “diabetes-friendly.” Fat-free products are often fortified with sugars and starches. And many gluten-free products have even more carbohydrates than their standard gluten counterparts.
If you’ve chosen a restaurant that can provide nutritional information, ask for it, so you’ll know exactly how many carbohydrates you’ll be consuming. Consider asking for salad dressings and sauces on the side.
Your Insulin Pump May Be Kinked
If you’re insulin-dependent, the first thing you should do at the sign of stubborn high blood sugar is to check to see if you have a kink in your insulin pump cannula. This can block the delivery of insulin, leading to a very frustrating day.
If you’re unsure, change your pump site! Make sure to call your insulin pump manufacturer to let them know of the issue, and they will usually mail you a replacement for free.
You’ve Injected Into Scar Tissue
If there’s no kink in the cannula, or if you’re using syringes to deliver multiple daily injections (MDI), you may have also just picked a “bad” site. When insulin is injected (either manually or with an insulin pump infusion set) into scar tissue, absorption suffers, resulting in unpredictable and high blood sugars.
Make sure to always rotate your sites as much as possible to avoid developing scar tissue and the inevitable high blood sugars they bring.
Your Medications Need Adjusting
Our bodies are constantly changing. It would be silly to expect the same insulin to carbohydrate ratio or insulin sensitivity factors or even the same number of milligrams of our oral diabetes medications for our entire lives.
Make sure you’re seeing your endocrinologist or diabetes doctor regularly; they can help refine your medication regimen.
You may be especially likely to require adjustments if you’ve recently lost or gained weight, have increased or decreased your activity levels, are going through a stressful life change, are pregnant, or planning on becoming pregnant, or haven’t been to the doctor for a while.
Your Medications Are Expired
Always check to make sure your medications aren’t expired! At room temperature, insulin will lose potency.
Oral medications can last much longer, but you still need to be cognizant of expiration dates and make sure you’re refilling your prescriptions regularly to avoid taking an expired (and potentially useless) dose.
What to Do When Your Blood Sugar Is High
High blood sugars can range from not-a-big-deal to a life-or-death emergency. Make sure to check your blood sugar often and monitor for any signs of diabetic ketoacidosis (DKA). If you have blood sugars that are over 250 md/dL for more than a few hours and you have moderate to high ketones, you will need to seek emergency medical care immediately. If you don’t have ketones, but want to feel better as soon as possible, try some of these tactics:
- Exercise – cardio (a walk, jog or even jumping jacks) can bring blood sugar down quickly
- Take a correction bolus of insulin
- Change your pump site
- Chug water
- Take a hot shower or bath
- Manage stress with a quick yoga sequence or meditation
- Test for ketones (if you have moderate or high ketones and your blood sugar has been high for several hours, call your doctor or go to the emergency room right away)
Understanding why you’re experiencing high blood sugars is one more way to improve your life with diabetes! Always work with your doctor before changing your oral medication and/or insulin therapy.
Have you ever experienced a mystery, stubborn high blood sugar? What helped you to get it down quickly? Share this post and comment below; we love hearing from our readers!
This content originally appeared on diaTribe. Republished with permission.
By Eliza Skoler
Why do your blood sugar levels increase at night, and what you can do to prevent this? Learn strategies for managing high blood sugar levels overnight and in the morning, including healthy bedtime snacks.
For National Sleep Awareness week, we are focusing on how to regulate overnight blood glucose (sugar) levels. With the many factors that can affect your glucose levels, nighttime can be a challenge. Some people with diabetes experience high overnight levels while others fear or experience a glucose drop during sleep. Trying to keep glucose levels stable overnight will help you get more sleep and feel better – and a good night’s sleep will aid your diabetes management the next day. While this article focuses on overnight highs, you can learn more about preparing for and preventing hypoglycemia (low blood sugar) here.
Here are some tips and strategies for how people living with diabetes can get better sleep at night and avoid high blood sugar levels.
Click to jump down:
Symptoms of High Blood Sugar at Night
Is It Safe to Sleep with High Blood Sugar?
Why Does Blood Sugar Go Up at Night?
What is the Dawn Phenomenon?
How to Stabilize Your Blood Sugar Overnight
Great Bedtime Snacks for People Living with Diabetes
What Should Your Blood Sugar be When You Wake Up?
How to Lower Morning Blood Sugar
If your blood sugar is high at night you may experience symptoms of hyperglycemia. Hyperglycemia, or “high glucose,” is not defined by one specific glucose level. While many people with diabetes aim to keep blood sugar levels below 180 mg/dl during the day, some people aim for the lower range of 120 or 140 mg/dl at night, when they are not eating.
At night, symptoms of hyperglycemia include:
- Poor sleep
- Waking up often to urinate or to drink water
- Dry mouth
Other symptoms of hyperglycemia that you may experience during the day or night include:
- Frequent and excessive urination
- Extreme thirst
- Blurry vision
- Shortness of breath
Glucose levels that are occasionally a little high at night generally don’t pose serious, immediate health concerns. Most people with diabetes cannot avoid some high glucose levels. However, frequent or long-term highs – particularly extremely high levels (above 250 mg/dl) – can be dangerous. It is important for people with diabetes to reduce high blood sugar as much as possible for two key reasons:
- Frequent hyperglycemia can lead to major health complications caused by damage to blood vessels and nerves, which can affect your eyes, heart, kidneys, and other organs. This occurs when glucose levels are too high over a long period of time.
- Very high glucose levels can be a sign of diabetic ketoacidosis (DKA, or high levels of ketones in your blood indicating that there is not enough insulin in your body). This occurs mainly in people with type 1 diabetes and can be life-threatening. For more information on DKA, read “Ketosis vs. Ketoacidosis: What’s the Difference.”
There are many factors that can cause your blood sugar to increase at night. For example: what food you ate during the day, how much and when you exercised, whether you ate snacks before bed, the timing of your insulin doses, and your stress level. You can experience different patterns of high blood sugar at night. You may start with high glucose when you go to bed, start the night in range but go high several hours later, or spend most of the night in range until the hours just before you wake up. By identifying your body’s patterns, you can figure out what is causing your high blood sugar and how to address it.
Common causes of a glucose increase at night include:
- Eating too close to bedtime: whether you’re snacking or eating a late dinner, a post-meal glucose spike can lead to high glucose levels overnight. In particular, high-fat, high-carb meals (like pizza or pasta with creamy sauces) might delay glucose absorption causing an extended period of high blood sugar levels.
- If you have type 2 diabetes, a treatment plan that doesn’t adequately address your nighttime insulin resistance or missed doses of your glucose lowering medication can cause high glucose levels at night (and often also during the day).
- Over-correcting a low glucose level before bed. If you need to bring your glucose level back into range before you sleep, take just enough glucose to stabilize your blood sugar. Quantity-limited treatments (like glucose tablets or small candies) that will raise your glucose levels by a specific amount can be very helpful – learn more here.
- If you take insulin, your insulin levels may be inadequate during the night. Depending on your dose and timing of basal insulin, the insulin may not last in your body until the morning. Learn about different types of insulin, insulin pumps, and automated insulin delivery (AID) systems, all of which can be helpful for staying in your target glucose range overnight.
- Taking less insulin before bedtime due to fear of low blood sugar overnight.
Another reason for high nighttime blood sugar levels is the “dawn phenomenon.” The dawn phenomenon occurs early in the morning when the body naturally signals your liver to produce glucose, giving your body the energy it needs to wake up.
The hormonal changes associated with the dawn phenomenon happen to people with or without diabetes, though those without diabetes do not experience hyperglycemia. If you take insulin, you may need to try a new basal insulin or adjust the timing and amount of your basal dose (with injected insulin) or your nighttime basal rates (with an insulin pump) to cover an early morning rise.
The most important thing you can do to stabilize your blood sugar is monitor your glucose levels at bedtime, during the night, and when you wake up to look for patterns. This will help you determine what’s going on in your body and how you can fix it. While there are many strategies people use to stabilize blood sugar at night, every person is different – you’ll have to look for trends in your body, experiment with ways to lower glucose levels over a period of time, and learn what works best for your body.
- Check your blood sugar (or CGM) before bed. If it’s already high, your blood sugar levels may remain high throughout the night. To address this, you’ll want to start by adjusting when you eat your evening meal and what it consists of, and how much mealtime insulin you take to cover it.
- Avoid eating lots of food close to bedtime. For diaTribe writer Adam Brown, the key to staying in range overnight is low-carb, early dinners, with no snacking after dinner.
- Consider eating less food at night and taking more basal insulin to cover your evening meal.
- Check your blood sugar (or CGM) during the night, between midnight and 3am. If you were in range before bed but have high glucose levels between midnight and 3am, you may need to adjust your basal insulin dosage and timing. If you are low during that time, you may experience a rebound high blood sugar later on – this is usually associated with overcorrecting the low.
- Talk with your healthcare team about the optimal nighttime insulin regimen for you. You may need to adjust your insulin to avoid both early low blood sugar and later high blood sugar.
- If you take basal insulin, see if you’re able to get an insulin pump or an automated insulin delivery (AID) system. AID systems will automatically adjust your basal insulin doses throughout the night to help keep your glucose levels stable.
- For some people, a small snack before bed (with a small dose of insulin, if appropriate) can help stabilize glucose levels throughout the night and avoid an early morning high. Keep reading for a list of healthy bedtime snacks.
- Check your blood sugar (or CGM) when you wake up. If you were in range before bed and between midnight and 3am, but have high blood sugar in the morning, you may be experiencing the dawn phenomenon or running out of insulin (or other medication).
- If you take insulin, you may need to delay the timing of your basal dose to as close to bedtime as possible. Or, you may increase your basal rates with an insulin pump from around 3am on.
- If you have type 2 diabetes, talk with your healthcare professional about your glucose-lowering medications to make sure that your treatment plan addresses overnight hyperglycemia.
It’s possible to experience a combination of these events – you may have high blood sugar levels at various points throughout the night. If you have a continuous glucose monitor (CGM, you’ll be able to better track your glucose levels throughout the night. You can use your CGM data to relate your behaviors to patterns in your nighttime glucose levels. Does the timing of physical activity affect your glucose levels overnight? What about food choices throughout the day, in terms of type, quantity, or timing of food? If you don’t have a CGM, the more frequently you can take a blood sugar readings the better. Learn how to get the most of your fingerstick blood sugar data here. It’s important to share your nighttime glucose observations with your healthcare team so that you can find the best ways to stabilize your blood sugar over the entire night.
For more advice on stabilizing nighttime glucose levels, read Adam Brown’s “The Overnight Blood Sugar Conundrum.”
For some people, a healthy bedtime snack helps to prevent glucose swings during the night. By eating a small snack that is full of protein and healthy fats (and low in carbohydrates), your body may be better able to avoid an overnight high – but if you take insulin, be sure to cover the carbohydrates in your snack even if it only requires a small dose of insulin.
Here are some snack ideas:
- Plain nuts or seeds – try eating a small handful
- Raw vegetables, such as carrots, celery, cucumbers, or tomatoes, with a small amount of hummus or peanut butter
- Plain yogurt, and you can add berries or cinnamon (read about choosing a healthy yogurt here)
- Chia seed pudding
Remember, a bedtime snack is only helpful for some people. To see if it works for you, you’ll have to carefully monitor your glucose before bed, during the night, and when you wake up.
The goal of diabetes management is to keep your blood sugar levels as stable as possible. This means that when you wake up, you want your glucose to be in range and to stay in range throughout the day.
For many people with diabetes, the overall target glucose range is between 70 mg/dL to 180 mg/dL (3.9 to 10.0 mmol/L). To start the day strong, the American Diabetes Association recommends that you aim to wake up with glucose levels between 80 to 130 mg/dL. Talk with your healthcare team about your glucose targets.
Whether a morning high is caused by the dawn phenomenon or something else, here are a few things you can try to lower your blood sugar levels:
- Physical activity when you wake up can help bring your glucose level down. Even going for a walk can be helpful.
- Eating a light breakfast can help keep a morning high from increasing even more. Taking your mealtime insulin will help lower your blood sugar.
- Adam Brown suggests eating a breakfast that is low in carbs, and notes that sometimes mealtime insulin has to be adjusted in the morning. One of his favorite breakfasts is chia pudding, since it has little impact on glucose levels; see what else he eats for breakfast here.
- Catherine Newman has six popular, low-carb, delicious recipes in “The Morning Meal.”
- Intermittent fasting and time-restricted feeding approaches to meal timing can also help people keep morning blood sugar levels in range. Read Justine Szafran’s “Intermittent Fasting: Stabilizing My Morning Blood Sugars” to learn more.
- For additional ways to navigate mornings, read seven strategies from Adam Brown in “A Home Run Breakfast with Diabetes.”
People with all types of diabetes are at a higher risk for numerous health complications, in particular for various vascular problems. While it is known that consistently tight glycemic management can greatly minimize these health risks, there are numerous factors which will determine long-term health outcomes.
One interesting concept is that of “metabolic memory,” a phenomenon that suggests high blood glucose levels experienced early on (for instance, before and some time after diagnosis) may still play a role in the development of complications years later, even if blood glucose has been generally well-managed. Several theories have been proposed as to why this may be, and most recently, researchers at the City of Hope conducted a study that may help explain why. The results of the study were recently published in Nature Metabolism.
Researchers selected patients from the DCCT/EDIC trials and compared their DNA to identify differences as they relate to glycemic management histories. The scientists were looking at something called DNA methylation, a process that involves the attachment of chemical groups (methyl groups) to specific regions of DNA.
The addition of certain chemical groups to DNA can change its function. This is one example of epigenetic regulation, a way that gene expression can be altered without a change in the actual DNA sequence (i.e., a mutation). These chemical groups that bind to the DNA can change the way that gene behaves, may affect the function of other genes and alter various physiological events downstream.
In this study, the authors report that they uncovered a connection between the HbA1c levels of patients at the end of the DCCT, their DNA methylation patterns, and the development of complications later in life. They believe that these differences in DNA methylation may promote the development of diabetes-related retinopathy and neuropathy (and likely other complications as well). In fact, many of these changes were occurring in genes that are directly relevant to the development of complications.
Rama Natarajan, PhD, one of the authors of the study, had this to say in a recent press release:
“This comprehensive study has systematically compared the epigenetic states of a large number of type 1 diabetic subjects with their glycemic history and their future development of key diabetic complications over 18 years. While the link between epigenetics and diabetes and related complications has been reported before, this is the first large scale study in type 1 diabetes showing that a prior history of high glucose levels can cause persistent changes in DNA methylation to facilitate metabolic memory and trigger future diabetic complications. This study provides the first evidence in humans supporting the link between DNA methylation in inflammatory and stem cells, a patient’s blood sugar history and development of future complications.”
Having a better understanding of detectable “markers” for complications before they even develop may mean earlier detection (i.e., via blood test) and more timely treatment of diabetes complications in the future. This research group is currently continuing to explore these findings, in collaboration with other research groups. They are planning to evaluate the relationship of DNA methylation and other diabetes-related complications, as well as investigate whether these changes may be a reliable biomarker for early detection. They are also investigating what other epigenetic changes may be relevant in metabolic memory.