12 Surprising Things That Can Cause High Blood Sugar Levels

Written by GHBY Team on Wed, 19 June 2024

Key Highlights

  • High blood sugar can bring about multiple health problems.
  • A sedentary lifestyle with poor eating habits & little exercise can cause blood sugar levels to remain high.
  • However, other factors such as lack of sleep & chronic stress may also be responsible for high blood sugar.

Research indicates that when blood-sugar levels stay at 140 to 150 for prolonged periods of time, beta cells (the cells in the pancreas that produce insulin) start to die, neuropathy can set in, eyes can be damaged, and the potential for heart disease rises dramatically.

It's not just food that can increase your blood sugar levels. There are several behavioral, biological, environmental factors, effects of medication, exercise and lifestyle habits that raise your risk of high blood sugar.

Here are 12 surprising things that can spike your blood sugar:

1. High-intensity exercise

Most of the time, working out causes blood glucose to dip. But some people, after certain types of exercise, notice that their glucose levels actually rise during or after exercise.

High-intensity exercise like weight lifting, jump-roping, sprints, and competitive sports, etc, can sometimes raise blood glucose. These workouts cause you to produce stress hormones like adrenaline. Adrenaline raises blood glucose levels by stimulating your liver to release glucose.

What you can do:

  • Choose moderate-intensity aerobic workouts, or circuit weight training with light weights and high repetitions.
  • Practice relaxation techniques such as paced breathing, visualisation, or meditation before and during your workout to minimise the adrenaline effect.

2. The dawn phenomenon

A natural rise in blood glucose occurs between about 4:00 and 8:00 a.m. This can result in higher blood sugar in the morning.

According to the Mayo Clinic, some researchers believe the natural overnight release of the so-called counter-regulatory hormones like including growth hormone, cortisol, glucagon and epinephrine increases insulin resistance, causing blood sugar to rise.

High morning blood sugar may also be caused by insufficient insulin the night before, insufficient anti-diabetic medication dosages or carbohydrate snack consumption at bedtime.

What you can do:

  • Avoid carbohydrates at bedtime.
  • Adjust your dose of medication or insulin, or change the timing of medication.

3. Cold weather

Cold weather is also known to reduce blood flow through the body, increase blood sugar levels, and even increase risks of complications for people with diabetes.

In colder temperatures, a lowered physical activity can increase insulin resistance, which, in turn, tends to increase blood sugar levels if you don't adjust the dosage properly.

Maintaining regular physical activity during winter can help to balance blood sugar levels. Winter is also cold and flu season. Viral infections are known to increase blood sugar levels.

What you can do:

  • If you are sick, be extra mindful of your blood sugar and make sure you measure your ketone bodies.

4. Smoking

According to the Centers for Disease Control and Prevention (CDC), insulin helps blood sugar enter cells, but nicotine changes cells so they don't respond to insulin, which increases blood sugar levels.

Type 2 diabetes

Chemicals in cigarettes harm cells in your body and cause inflammation. This also makes cells stop responding to insulin. People who smoke have a higher risk of belly fat, which increases the risk for type 2 diabetes even if they aren't overweight.

So, if you smoke, you're 30% to 40% more likely to get type 2 diabetes than people who don't smoke. The more you smoke, the higher your risk.

What you can do:

  • Quitting smoking helps your body use insulin better, which can make your blood sugar levels easier to manage.

5. Eye drops

According to a 2007 study published in the journal 'Ophthalmologica', using topical corticosteroids drops for a short period of time (7 days) seems to statistically raise the blood glucose levels in patients with controlled diabetes, which, however, returns to pretreatment levels after discontinuation of the eye drops without any side effects.

In another study published in the journal 'Current Eye Research', dexamethasone eye drops have a greater effect on the blood glucose profile of diabetic patients than on nondiabetic patients.

6. Illness and infections

Diabetes also can lower the amount of blood flow in your feet. Not having enough blood flowing to your legs and feet can make it hard for a sore or an infection to heal.

According to Diabetes UK, people with diabetes are already at higher risk for foot problems, so when they happen, as part of the body's defense mechanism for fighting illness and infection, more glucose is released into the blood stream.

People who don't have diabetes just produce more insulin to cope. But when you've got diabetes, your body can't do this. The symptoms of diabetes can add to those of the original illness or infection and make it much worse.

Feeling or being sick, or having diarrhoea can make your blood sugar levels drop, because you're not absorbing food as usual.

7. Dehydration

Dehydration or less water in your body means your blood sugar is more concentrated. According to a 2017 study published in the journal 'Nutrition Research', adult men with type 2 diabetes going only three days with subpar water intake (17-34 ounces per day) had impaired glucose response.

Even a mild level of dehydration could easily leave your blood sugar levels 50 to 100 mg/dL higher than if you were drinking enough water. If you're consistently dehydrated on a daily basis, you might even be compensating with higher insulin levels than you'd need if your body was getting the water it needed.

More severe levels of dehydration can drive blood sugars very high quickly. Have enough water in your body.

8. Too little sleep

Noted researchers from the University of Chicago Medical Center in a study published in the journal 'The Lancet' have written that chronic sleep loss can reduce the capacity of even young adults to perform basic metabolic functions, such as processing and storing carbohydrates or regulating hormone secretion.

Cutting back from the standard eight down to four hours of sleep each night produced striking changes in glucose tolerance and endocrine function-changes that resembled the effects of advanced age or the early stages of diabetes-after less than one week.

Researchers found profound alterations of glucose metabolism, in some situations resembling patients with type-2 diabetes, during sleep deprivation.

When tested during the height of their sleep debt, volunteers took 40% longer than normal to regulate their blood sugar levels following a high-carbohydrate meal. Their ability to secrete insulin and to respond to insulin both decreased by about 30%. A similar decrease in acute insulin response is an early marker of diabetes.

9. Too little exercise

When you exercise, insulin sensitivity is increased, so your muscle cells are better able to use any available insulin to take up glucose during and after activity. Not getting enough physical activity can raise a person's risk of developing type 2 diabetes.

Physical activity helps control blood sugar, weight, and blood pressure and helps raise 'good' cholesterol and lower 'bad' cholesterol. Adequate physical activity can also help reduce the risk of heart disease and nerve damage, which are often problems for people with diabetes.

blood sugar levels

According to the Physical Activity Guidelines for Americans published by Health and Human Services (HHS), simply moving more frequently throughout the day provides substantial and immediate benefits.

Physical activity helps reduce anxiety and blood pressure, improve quality of sleep and insulin sensitivity, and fend off the progression of Type 2 diabetes and hypertension. Regardless of your current level of fitness, simply being active opens up ways to live healthier.

10. Excessive chronic stress

Glucocorticoids are stress hormones. High levels of these hormones might stop insulin-producing beta cells in the pancreas from working properly and reduce the amount of insulin they make. In turn, this might contribute to the development of type 2 diabetes.

Family conflict, illness, unhealthy relationships, workplace challenges or emergency situations like natural disasters can all cause extreme stress, depending on your coping mechanisms and how resilient you are. If stress doesn't go away, it can keep your blood sugar levels high and put you at higher risk of diabetes complications.

Diabetes is often a cause of stress too, particularly in the early days when you've just been diagnosed. Having to pay close to attention to what you eat and having lots of new things to learn and remember can be tough.

It may mean you now have to check your blood sugar levels a lot or inject yourself every day. Worrying about what the results will say or feeling anxious about needles can be really stressful.

11. Certain medications

According to WebMD, certain medicines you might take to keep yourself healthy can cause a spike, too.

Prescription medicines that can raise your glucose include:

  • Steroids or corticosteroids. They treat diseases caused by inflammation, like rheumatoid arthritis, lupus, and allergies
  • Drugs that treat anxiety, ADHD, depression, and other mental health problems
  • Birth control pills
  • Drugs that treat high blood pressure, such as beta-blockers and thiazide diuretics
  • Statins to lower cholesterol
  • Adrenaline for severe allergic reactions
  • High doses of asthma medicines
  • Medication, which you get after an organ transplant
  • Some medicines that treat HIV and hepatitis C
  • OTC medicines that can raise your blood sugar include some cold and flu medicines

12. Gum disease

According to the American Diabetes Association, people with diabetes, especially uncontrolled diabetes, have more gum disease than those without diabetes. We have known that for a long time.

Now, scientists are finding that gum disease may raise blood sugar levels in people with and without diabetes. Scientists think that some of the germs in infected gums leak into the bloodstream after normal activities such as chewing or tooth-brushing. This starts a reaction from your body's defense system, which, in turn, produces some powerful molecules that have harmful effects all over your body - an example is raising your blood sugar level.

In people with type 2 diabetes, treatment of severe disease (for instance, deep cleaning) can lead to a drop in blood sugar levels. Keep your gums as healthy as possible, whether or not you have diabetes.


There are several factors that affect blood sugar. Not every person will respond in the same way, and the response may change from day to day or within a day with you. The best way to see how a factor affects you is through personal experience.

Having your blood-sugar levels high for long periods of time throughout the day will drain your health. Every hour that your blood sugar is significantly higher than normal your kidneys are being attacked, your heart is weakening, and your mouth, eyes and feet are in danger.

Knowing what raises your blood sugar will help you make a few simple changes that can improve your health. A journey of a thousand miles, it is said, begins with a single step.



GHBY Team comprises content writers and content editors who specialise in health and lifestyle writing. Always on the lookout for new trends in the health and lifestyle space, Team GHBY follows an audience-first approach. This ensures they bring the latest in the health space to your fingertips, so you can stay ahead in your wellness game. 

Did you like our Article?





Not Sure





  1. Philip kolil

    Thu, 13 April 2023, 1 year ago


    • DrAung Phyo

      Wed, 12 April 2023, 1 year ago

      good article

      • Nakibuuka Betty

        Thu, 08 December 2022, 1 year ago

        It's a useful article,am living with diabetes,I take oral medication ,I will need boaster information

        • GHBY Team

          Thu, 05 January 2023, 1 year ago

          We have taken note of your comment. We will soon have something on the information you are looking for.

        • Brigitte Appiah

          Wed, 30 November 2022, 1 year ago


          • GHBY Team

            Thu, 05 January 2023, 1 year ago

            Thank you for reading. We are glad you find our blogs useful.


          Leave a Comment

          1. Why Does Exercise Sometimes Raise Blood Glucose
          2.  The dawn phenomenon: What can you do?
          3. How Do Colder Temperatures Influence Blood Sugar Levels?
          4. Randomized Controlled Trial Ophthalmologica. 2007;221(6):426-9. doi: 10.1159/000107505 - pubmed
          5. Bahar I, Rosenblat I, Erenberg M, Eldar I, Gaton D, Avisar R, Weinberger D. Effect of dexamethasone eyedrops on blood glucose profile. Curr Eye Res. 2007 Sep;32(9):739-42. doi: 10.1080/02713680701573704. PMID: 17882705.
          6. Diabetes when you're unwell
          7. Reduced water intake deteriorates glucose regulation in patients with type 2 diabetes
          8. Water and Diabetes: Are You Drinking Enough Water?
          9. Lack of sleep alters hormones, metabolism, simulates effects of aging
          10. Blood Sugar and Exercise
          11. What Medicines Can Make Your Blood Sugar Spike?
          12. Dr.Hyman

          Our team of experts frequently monitors developments in the health and wellness field, and we update our articles when new information becomes available.

          Current Version

          Jun, 19 2024

          Written By

          GHBY Team

          Aug, 01 2023

          Written By

          GHBY Team