Why Is My Blood Sugar Spiking?

For many people with diabetes, your blood glucose is a daily — and sometimes even hourly — indicator of how you're feeling and doing. But what does it mean when your blood sugar spikes — and what causes it to spike?

Key Takeaways: Blood Sugars

• Your glucose should rise after you eating because that shows that carbohydrates are digesting. Once carbohydrates enter the bloodstream, the pancreas releases insulin and delivers it to the cells. However, if your blood sugar spikes following a meal, it could indicate that something is awry.
• Research has found that people who have more blood sugar swings are more likely to have heart disease, stroke, foot ulcers or diabetic eye disease, compared with people with more stable blood glucose management.
• Caffeine, stress, illness and even exercise can cause your blood sugar to spike.

Glucose Levels: The Basics

According to the American Diabetes Association (ADA), the recommended blood glucose targets include:

• Fasting/premeal: 80-130 mg/dL
• Two hours following a meal: 80-180 mg/dL

Your glucose should rise after you eat a meal because that's an indication that carbohydrates are digesting. Once carbohydrates enter the bloodstream, the pancreas releases insulin and delivers it to the cells. However, if your blood sugar spikes following a meal, it could indicate that something is awry.

Why It's Important To Keep Blood Sugars Steady

If you have diabetes, keeping your blood sugar levels stable over time may be key to living longer.

Research has found that people who have more swings in their blood sugar levels are more likely to have heart disease, stroke, foot ulcers, diabetic eye disease or die early, compared to people with more stable blood sugar management.

The study authors used a test called hemoglobin A1C to measure blood sugar. This commonly used test provides a rough estimate of about two to three months of average blood sugar levels.

A hemoglobin A1C test provides a rough estimate of about two to three months of average blood sugar levels. Most people with diabetes generally aim for an A1C of 7% or lower. Higher A1C numbers may indicate the need to change medications or lifestyle factors.

Several factors can affect A1C levels, including how well the body's insulin-producing cells work, body weight, lifestyle management, other illnesses and diabetes medications.

Factors That Can Elevate Your Blood Sugar

Knowledge is power — and so is knowing how everyday activities can impact your glucose. There are more than 40 factors that can impact your glucose levels. Some of the most common reasons for elevated blood glucose levels include:

Alcohol

Alcohol metabolizes in the liver, which is also responsible for releasing glucose when your blood sugar is low. When the liver is busy metabolizing alcohol, it does not release glucose into the bloodstream as quickly. Alcohol can increase or decrease your glucose, depending on factors like:

• Portion sizes
• How many carbohydrates are in each beverage
• Food consumption with alcohol

Caffeine

Caffeine can sometimes elevate blood glucose, as well as cause insulin resistance.

Exercise

Exercise can increase your blood glucose, but in general, daily exercise is important to help keep your glucose in a target range.

Low to moderate activities like walking can lower blood glucose.

High-intensity exercise causes your body to release stored glucose from the liver to help fuel your muscles, which can temporarily increase your blood glucose.

Illness

Illness can affect your glucose levels because the body releases stress hormones to fight off infection or inflammation, which elevates glucose levels.  

Medications

Medications, including corticosteroids, some cold medications and beta-blockers, can impact your glucose.

Sleep

When limited, lack of sleep can cause the body to be stressed and release hormones that can raise blood glucose and make your body more resistant to insulin.

Stress

There's a strong link between stress and blood sugar levels, and cortisol, the body's main stress hormone, plays a key role.

When you're stressed, your body releases cortisol, which leads to an increase in blood sugar and a decrease in insulin, the hormone that helps process that sugar. This results in elevated glucose and potential insulin resistance.

"Prolonged stress can make it difficult to manage your glucose numbers," Crosby said. "Try to manage your stress with moderate daily exercise, a balanced diet, and plenty of rest."

Hypercortisolism -- higher-than-normal levels of cortisol -- can cause weight gain, high blood pressure, muscle weakness and mood changes. All these problems can further complicate diabetes management.

Blood Sugar Spiking In The Middle Of The Night

The "dawn phenomenon" is a natural response that everyone experiences — diabetic and non-diabetics alike. Between 2 and 8 a.m., our bodies release hormones to begin preparing for the day. These hormones can cue glucose to be released by the liver, which can cause elevated blood glucose levels for people those who have insulin resistance or do not produce enough insulin.   If your fasting glucose is consistently elevated in the morning, try to check your glucose between 2 and 4 a.m. Repeat for a few days, and record the data for your doctor. 

"Having elevated glucose for an extended period increases your risk for diabetic complications," said Amanda Crosby, certified diabetes educator at Franciscan Healthy Living Center Lafayette. "We can work with patients to modify diet, change medication dosages, and create a meal plan that helps your body better regulate glucose at night." 

Signs That It's Time to Get Medical Help

Keeping a close tab on your blood glucose is critical for your overall health and wellness. If you are experiencing concerning symptoms or consistently low (under 70 ml/dL) or high (> 250 ml/dL) glucose counts, it's time to see your doctor.

Worrisome symptoms that warrant medical attention for your diabetes include:

• Increased thirst, dry mouth, and frequent urination with blood glucose over 250.
• Experiencing hypoglycemia or hyperglycemia symptoms that do not improve with intervention. Symptoms include:
• Hypoglycemia: Shaking, impaired vision, weakness/fatigue, dizziness, sweating, headache, and irritability. If you are experiencing hypoglycemia symptoms, check your glucose monitor and treat if you are below 70. Seek medical attention if your symptoms do not improve after eating.
• Hyperglycemia: Blurred vision, frequent urination, hunger, dry skin, drowsiness, nausea, and extreme thirst. It is essential to be aware of symptoms caused by blood sugar elevations, as your body can grow used to these symptoms and cause long-term complications.
• Blisters, redness, swelling, bleeding, fluid oozing, black and blue marks, or open sores on your feet should also be examined by your doctor.