People with diabetes need to monitor their blood sugar levels to avoid spikes. If a person’s blood sugar is excessively or consistently high, they may experience thirst, blurred vision, and headaches.

Diabetes is a disease that can cause blood glucose to reach dangerously high levels. If a person does not control these levels, complications can develop.

In some cases, it is possible to moderate blood glucose levels through lifestyle adjustments. However, some people may require medications.

This article looks at the triggers and complications of blood spikes and explains how to manage blood sugar levels. It also discusses blood sugar spikes in people without diabetes.

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Glucose comes from food. It is a simple sugar that serves as the main source of energy for the body.

The pancreas secretes a hormone called insulin that makes cells more sensitive to glucose. The cells then draw glucose from the blood, reducing the effects of blood sugar spikes.

In a person with diabetes, either the pancreas does not produce insulin or the cells develop a resistance to this hormone. As a result, the glucose remains in the blood, keeping blood sugar levels consistently high. This is called hyperglycemia.

In people living with diabetes, blood sugar spikes often occur after eating. On average, this occurs 75 minutes after starting a meal.

However, if a person is unable to manage their condition, they may have persistent high blood glucose levels. This can lead to complications of diabetes, including nerve damage, vision loss, kidney damage, kidney problems, and an increased risk of cardiovascular disease.

Learn more about hyperglycemia and diabetes.

Typically, hyperglycemia does not cause symptoms until blood glucose reaches an excessive or consistently high level.

Some early symptoms of hyperglycemia include:

Both type 1 and type 2 diabetes can cause hyperglycemia. The symptoms may appear suddenly in people with type 1 diabetes, but they tend to develop more slowly in those with type 2 diabetes.

In cases of type 1 diabetes, as blood sugar levels continue to rise unchecked, ketones may start to build up in the blood and urine. Ketones are a type of acid that can accumulate in the blood when insulin levels are too low.

High levels of ketones in the blood can be severe. They can cause the following symptoms:

  • fruity-smelling breath
  • shortness of breath
  • dry mouth
  • weakness
  • nausea and vomiting
  • confusion

Doctors should provide people with information about what to do after an unusually high blood sugar reading and when to seek help.

People with any type of diabetes must regularly monitor and manage their blood glucose levels to prevent spikes. They may find the following strategies helpful:

Keeping track of blood sugar levels

Knowing when to call the doctor or seek emergency care is essential. Severe blood sugar spikes can lead to advanced health problems.

Anyone experiencing hyperglycemia symptoms should immediately check their blood sugar levels. They should contact the doctor if the reading is above 180 milligrams per deciliter within 2 hours of eating a meal.

It may also help to record blood sugar levels in a journal and look for patterns, such as blood sugar spikes occurring every morning. If this happens, it might be time to check with the doctor about adjusting the dosage of insulin. If blood sugar levels are consistently high after meals, a doctor may advise a person to take insulin during meal times.

A person should also be sure to bring this journal to medical appointments. The doctor can review the results and recommend any necessary adjustments to the management plan.

Leading a healthy lifestyle

In the early stages of type 2 diabetes, a person may be able to maintain stable blood sugar levels without needing medication.

Regular exercise that is light to moderate in intensity uses up some of the excess blood glucose and brings down overall levels.

Likewise, following a low glycemic index (GI) diet with strict portion sizes can help reduce the amount of glucose in the body and the accompanying risk of spikes. The GI ranking indicates the extent to which carbohydrates in a given food will affect blood sugar levels.

Foods with a high GI, meaning a ranking of 70 or higher, include bagels, popcorn, and crackers. Low GI foods, which have a score of 55 or less, include barley, bulgur, corn, and sweet potatoes.

People with type 1 diabetes should also do their best to lead a healthy lifestyle. However, these individuals will also need to take supplemental insulin on a lifelong basis.

Using medications and smart pumps

If following a strict medication and diet regimen does not prevent these spikes from occurring, a person should let their prescribing doctor know. The doctor will likely adjust their prescription.

Diabetes management also requires anyone taking insulin or non-insulin medication to stick to specific timings.

A range of pumps and smart pumps is available to provide continual, timed doses of insulin. These devices provide background insulin to regulate blood glucose levels during fasting periods and sleep. Their use is more common among people with type 1 diabetes than those with type 2 diabetes.

Smart pumps connect to a continuous glucose monitor and can respond to blood sugar spikes, essentially working as an artificial pancreas. However, with all pumps, manual inputs are still necessary during meals.

Learn about the different medications for type 2 diabetes.

People with diabetes have to be especially careful about keeping their blood sugar levels under control and avoiding spikes in blood sugar.

Various triggers can contribute to these spikes. For example:

  • Diet: Foods high in sugar or carbohydrates are more likely than other foods to raise blood sugar levels.
  • Lack of physical activity: A sedentary lifestyle can cause spikes in blood sugar levels. On the other hand, high intensity exercise can lead to physical stress, which is also a trigger for blood sugar spikes. People with diabetes need to get regular exercise rather than high intensity exercise. However, if a person does want to do high intensity exercise, they can try high intensity interval training (HIIT).
  • Smoking: Smoking cigarettes can make it difficult to keep blood sugar levels within a normal range. A person who smokes should make it a priority to quit. People who smoke may need to take larger doses of insulin to keep their blood sugar under control.
  • Stress: When the body is under a lot of stress, it produces hormones that increase glucose and reduce the effectiveness of insulin. As a result, more glucose stays in the bloodstream. Finding a way to keep stress levels down, such as yoga or meditation, is essential for people with diabetes.
  • Sleep problems: Prioritizing good sleep hygiene is important for several reasons. For people with diabetes, a regular sleep schedule becomes an important factor in glycemic control. A lack of sleep can lead to an increase in blood sugar levels.
  • Medication side effects: Some medicines can cause blood sugar levels to rise. These include, for example, corticosteroids, diuretics, some blood pressure medications, and some antidepressants. A person with diabetes should let their healthcare team know if they are also taking one of these types of medications. In addition, taking the wrong dose of insulin or missing a dose can cause blood sugar levels to spike.

Persistent blood sugar spikes can have severe consequences.

Diabetic ketoacidosis

Diabetic ketoacidosis is a dangerous complication of hyperglycemia.

It occurs when the body compensates for a shortage of insulin by breaking down fat for energy. This produces ketones, which are toxic waste compounds. A person usually expels ketones in their urine.

If too many ketones build up in the blood, they will not all leave in the urine. Without treatment, diabetic ketoacidosis can lead to coma and, in some cases, death.

Hyperglycemic hyperosmolar syndrome (HHS)

HHS occurs when the body continues to produce insulin, but the hormone does not work well or at all. This usually happens in cases of type 2 diabetes.

In this situation, glucose still builds up in the blood. The extra blood sugar leaves the body through the urine, causing extreme dehydration, coma, and even death.

High blood sugar can have other long-term health complications, including:

  • heart disease
  • nerve damage
  • kidney damage or failure
  • blindness
  • damage to the feet, leading to amputation
  • infections of the skin
  • problems with the teeth and gums

Keeping blood sugar levels under control and preventing spikes is essential to staying healthy. A person should speak with a doctor about any concerns or recurrent spikes.

It is possible for people without diabetes to get blood sugar spikes. Certain factors can trigger hyperglycemia in anyone.

For example, a 2017 study showed that when eating certain foods, blood sugar can spike equally high in people with diabetes and those without.

Several other issues can increase the risk of a blood sugar spike in people without diabetes. These include:

In addition, research suggests that Native American, Hispanic, Asian American, Pacific Islander, and African American people are more at risk of high blood sugar than white people.

A person with one or more of these risk factors may wish to consider consulting a doctor to discuss their blood glucose levels. The doctor will make personalized recommendations on how the person can address and minimize their risk factors.

Below, we answer some common questions about high blood sugar.

Are all exercises safe for reversing prediabetes?

Exercise does not pose any additional risks to people with prediabetes. However, it is advisable for anyone with any health concerns to speak with a doctor before beginning a new exercise regimen.

How do I reduce my blood sugar levels immediately?

A person will need to take fast-acting insulin to lower their blood sugar quickly. Exercising may also help a person get their blood sugar down. If none of this works, and the levels are very high, a person may need to go to the hospital.

Why is my blood sugar high when I have not eaten?

This so-called dawn phenomenon can happen when a person wakes up after an extended period of not eating. It occurs because the body releases hormones that help the person wake up, and these hormones can raise a person’s blood sugar temporarily.

People living with diabetes typically experience blood sugar spikes right after eating. High blood sugar is called hyperglycemia. A person can usually control these spikes with insulin, medications, or lifestyle strategies.

When a person’s blood sugar spikes are not under control, complications can occur. Some of these may be life threatening.

A person can prevent complications by working with their doctor to get the right diabetes medication and dosage and lead a preventive lifestyle that includes an appropriate diet and sufficient exercise.

In some cases, people who do not have diabetes can also experience blood sugar spikes. This can happen during an illness, after physical trauma, or as a result of stress.