Metabolic Health 14 MIN READ

Blood glucose level rise and crash guide

Blood sugar levels fluctuate all day long. Patterns of rises and crashes can offer valuable and actionable insights into your metabolic health.

Written by Team Ultrahuman

May 21, 2022
blood sugar rise

Blood sugar levels fluctuate all day long. Patterns of rises and crashes can offer valuable and actionable insights into your metabolic health.

In this piece, we delve into the causes behind these glucose highs and lows, why your blood sugar surges steeply after you eat, why it drops after alcohol intake, and more.

Firstly, it’s important to understand the different ways in which the hormone, insulin, behaves in the body and the process of glucose metabolism.

sugar in spoon


  • After eating, blood sugar levels rise. Insulin released by the pancreas helps the cells to absorb blood sugar for energy and storage,
  • Glucose is the fuel of the brain. If the blood glucose levels continue to drop, the brain will cease to get enough glucose and thereby stop functioning efficiently,
  • Low carb meals, not skipping meals, and limiting caffeine are some ways to prevent and manage reactive hyperglycemia.

Glucose Metabolism

Insulin is a hormone created by the pancreas that controls the amount of glucose in a person’s bloodstream at any given moment.

It helps store glucose in the liver, fat, and muscles, and regulates the body’s metabolism of carbohydrates, fats, and proteins.

After eating, blood sugar levels rise. Insulin released by the pancreas helps the cells to absorb blood sugar for energy and storage. With this absorption, glucose levels in the bloodstream begin to decline.

The pancreas then produces glucagon, a hormone that prompts the liver to release stored sugar.

This interaction of glucagon and blood sugar ensures stable blood glucose levels in the body and the brain. The cells of individuals who have insulin resistance don’t respond well to insulin, barring glucose from entering them with ease.

The glucose level in their blood rises over time even as their body produces more insulin as the cells resolutely resist insulin.

Circulating glucose is gleaned from three sources: intestinal absorption during the fed state, glycogenolysis, and gluconeogenesis.

The dominant determinant of the speed with which glucose appears in the circulation during the fed state is the rate of gastric emptying.

Circulating Glucose are Mainly Hepatic Processes

Glycogenolysis, the breakdown of glycogen, the polymerized storage form of glucose; and gluconeogenesis, the formation of glucose primarily from lactate and amino acids during the fasting state.

Glycogenolysis and gluconeogenesis are partially under the influence of glucagon, a hormone produced in the α-cells of the pancreas. During the first 8–12 hours of fasting, glycogenolysis is the main mechanism by which glucose is made available.

Glucagon facilitates this process and thus promotes glucose appearance in the circulation. Over longer periods of fasting, glucose, produced by gluconeogenesis, is released from the liver.

What is Non-diabetic Glucose Crash (Reactive Hypoglycemia)?

A sudden drop in blood glucose levels in the body is referred to as hypoglycemia. This means that there is excess production of insulin in the body, causing the cells to absorb more blood glucose than is required to maintain the optimal level.

It is typically characterized by a blood glucose level below 70 milligrams per deciliter (mg/dL). Non-diabetic glucose crash or non-diabetic hypoglycemia is hypoglycemia that occurs in people without diabetes.

Two types of Non-Diabetic Hypoglycemia

1.Fasting Hypoglycemia:

Fasting hypoglycemia happens when the blood glucose levels crash below 70 milligrams per deciliter (mg/dL), after the person goes without food for 8 hours or longer.

2.Postprandial or Reactive Hypoglycemia

Reactive hypoglycemia usually occurs when the blood glucose levels crash below 70 milligrams per deciliter (mg/dL), about 2 to 4 hours after a meal.

Non-diabetic Glucose Crash Symptoms

Before testing for low blood sugar levels, the body gives certain distinct indicators that suggest the blood sugar has dropped. The following are those indicators

  1. Shakiness,
  2. Nervousness or anxiety,
  3. Sweating, chills, and clamminess,
  4. Irritability or impatience,
  5. Confusion,
  6. Fast heartbeat (tachycardia),
  7. Lightheadedness or dizziness,
  8. Hunger,
  9. Nausea,
  10. Colour draining from the skin (pallor),
  11. Sleepiness,
  12. Weakness or lack of energy,
  13. Blurred or impaired vision,
  14. Tingling or numbness in the lips, tongue, or cheeks,
  15. Headaches,
  16. Coordination problems, clumsiness,
  17. Nightmares or crying out during sleep,
  18. Seizures.

Two Main Causes for Glucose Crash

1.Fasting Hypoglycemia

  1. Certain allopathic medications such as salicylates (including aspirin), sulfa drugs (an antibiotic), pentamidine (to treat a serious kind of pneumonia), and quinine (to treat malaria),
  2. Herbal supplements such as fenugreek, ginseng, or cinnamon,
  3. Alcohol, especially binge drinking,
  4. Exercise,
  5. Serious illnesses, such as those affecting the liver, heart, or kidneys,
  6. Low levels of certain hormones, such as cortisol, growth hormone, glucagon, or epinephrine,
  7. Eating disorders or malnutrition,
  8. Stomach surgery or hemodialysis,
  9. Tumors, such as a tumor in the pancreas, which produces insulin.

2. Reactive Hypoglycemia

The exact causes of reactive hypoglycemia are still uncertain. The following are some suggestive causes of reactive hypoglycemia

  1. Hyperinsulinism – excessive amounts of insulin in the blood
  2. Meals high in refined carbohydrates such as white bread or foods high in sugar
  3. Prediabetes or high risk for diabetes
  4. Rare enzyme deficiencies that make it hard for the body to break down food
  5. Any surgery of the digestive system that makes the food pass too quickly into the small intestine
  6. Another uncommon cause is dumping syndrome, which causes the body to release excess insulin after eating a carbohydrate-filled meal.

Why is it important to manage glucose drop?

When the blood sugar level drops, the muscles and brain cells do not have enough energy to work well.Glucose is the fuel of the brain. If the blood glucose levels continue to drop, the brain will cease to get enough glucose and thereby stop functioning efficiently.This can lead to blurred vision, difficulty concentrating, confusion, slurred speech, numbness, and drowsiness.If blood sugar stays low for a prolonged period, starving the brain of glucose, it may lead to seizures, coma, and very rarely death.

Eight ways to prevent and manage reactive hypoglycemia [Glucose Crash]

Multiple lifestyle changes that can be made to help prevent and manage Reactive Hypoglycemia are

small meals glucose

1.Smaller Meal Sizes

Eat 5 to 6 small meals instead of 3 large meals. Choose to eat every 3 hours if possible.

2.Reduce the carbohydrate intake

Have 1-2 servings of carbohydrates instead of 3-4 servings. Count the carbohydrate intake to see the level that works well for your body.

3.Do not skip meals

4.Avoid refined carbs and sugars

Limit refined carbohydrates and sugars such as white bread, pastries, sodas, candy, and syrups.

5.Include high fibre and starchy foods

Choose foods that are high in soluble fibre such as fruits and vegetables with their skin, oatmeal, and bran for each meal. Choose starchy foods with a low glycemic index such as oatmeal, peas, lentils, parboiled rice, etc. for each meal. They help maintain blood glucose levels.

6.Limit Caffeine

Try to limit the consumption of caffeine drinks and foods such as tea, coffee, and sodas. The impact of caffeine on glucose levels is that it affects how your body responds to insulin.

Caffeine may lower your insulin sensitivity. When insulin sensitivity is reduced, insulin resistance sets in. That means your cells don’t react to the hormone as much as they once did.

They don’t absorb as much sugar from your blood after you eat or drink. This causes your body to make more insulin, so you have higher levels after meals.

7.Limit alcohol intake

The liver is a vital organ in regulating blood sugar levels. One of its functions is to produce glucose through glycogenolysis (turning glycogen into glucose) or gluconeogenesis (manufacturing necessary sugar or glucose by harvesting amino acids, waste products, and fat byproducts).

Drinking alcohol impacts the liver and, more specifically, its ability to release glucose into the bloodstream. The liver makes and releases blood sugar in the bloodstream when one sleeps or between meals. Alcohol obstructs this process.

When it breaks down in the liver, it intercepts the production of new glucose and leads to a decline in glucose levels, and increases insulin secretion.

Alcohol initially leads to a spike in glucose level, which is generally metabolized speedily, but this could lead to a sharp drop a little further into a heavy drinking session.

Therefore, women should limit it to one drink a day while men should limit it to 2 drinks a day. A drink of alcohol is 12 ounces of beer, 5 ounces of wine, or 1½ ounces of liquor. Always drink alcohol with meals and not on an empty stomach. Avoid mixing alcohol with sugary drinks.

8.Eat proteins and vegetables

Include proteins and vegetables in your diet. Lean proteins are a preferred source of food. Foods such as beef, pork, fish, poultry (chicken and turkey), beans, and nuts are high in protein. Eat a variety of vegetables with your meals.

slows digestion and deters post-meal blood sugar spikes, as well as increases feelings of satiety.

glucose increase guide

What is Non-diabetic Glucose Rise (Postprandial/Reactive Hyperglycemia)?

cHyperglycemia is the state in which there is an excess amount of glucose in the blood. This means that the cells in the body are unable to absorb glucose efficiently, despite the secretion of insulin by the pancreas.

Hyperglycemia that occurs in people without diabetes is referred to as non-diabetic hyperglycemia.

Two types of non-diabetic Hyperglycemia

  1. Fasting Hyperglycemia
    If the blood sugar level after 8 hours of fasting (or longer) is over 125 – 130mg/dL, it is considered fasting hyperglycemia.
  2. Postprandial/Reactive Hyperglycemia
    If the blood sugar levels post 1-2 hours of eating is greater than 180mg/dL, it is called postprandial or reactive hyperglycemia.

Non-Diabetic Glucose Rise Symptoms

Even before testing for high blood sugar levels, certain common indicators can serve as a warning for postprandial/reactive hyperglycemia.

The following are the most common symptoms

  1. Increased thirst and/or hunger,
  2. Frequent urination,
  3. Headache,
  4. Blurred vision,
  5. Fatigue,
  6. Sugar in your urine (as determined by a urine test),
  7. Weight loss,
  8. Vaginal and skin infections,
  9. Slow-healing cuts and sores.

Nine main causes for blood sugar level rise

1.Cushing’s Syndrome

This syndrome is caused by excess secretion of a hormone from the anterior end of the pituitary gland called adrenocorticotropic hormone, which causes excess cortisol production from the adrenal glands. Another leading cause of Cushing’s Syndrome is pituitary adenomas or colloquially known as pituitary tumours.

The cortisol levels of people with Cushing’s Syndrome spike, increasing the risk of developing impaired glucose intolerance and hyperglycemia.

Cortisol is a hormone that counteracts the effects of insulin. It blocks the uptake of glucose from the bloodstream and increases insulin resistance, thereby maintaining high glucose levels in the bloodstream.

Elevated cortisol levels are also known to decrease the amount of insulin produced by the pancreas. Approximately 10% to 30% of people with Cushing’s syndrome will develop impaired glucose tolerance.

2.Pancreatic disease

Any pancreas-related disease such as pancreatitis and pancreatic cancer can cause an imbalance in the insulin levels produced by the pancreas. This improper secretion of insulin adversely impacts the blood sugar by preventing the absorption of excess glucose from the blood.

3.PCOS (Polycystic Ovarian Syndrome)

Polycystic Ovary Syndrome is a syndrome that commonly affects the endocrine system of women of different reproductive age groups. This condition affects roughly one in every ten women, causing infertility in women of childbearing age.

Women with PCOS often have imbalanced hormones, increasing the levels of insulin in their bodies. Although there is excess insulin in the body, the absorption of glucose from the body amongst women with PCOS is low.

As many as 30% to 40% of women who have polycystic ovary syndrome (PCOS) also have insulin resistance.

4.Surgery or stress

Any physical stress on the body can cause changes, more specifically after surgery. Surgeries increase cytokines and hormones that drive the production of glucose in the liver and block the effects of insulin from removing excess glucose from the blood.

Up to 30% of patients can develop stress-induced hyperglycemia after surgery, with blood glucose levels that stay elevated long after being discharged from the hospital.


Any infection in the body causes hyperglycemia as a result of increased cortisol. Cortisol, as mentioned above, blocks the ability of insulin to remove excess glucose from the bloodstream, keeping the blood sugar levels high.

Additionally, blood glucose spikes in the presence of an infection to support the kidneys, brain, and red blood cells that depend on glucose for energy to aid the immune system’s response to fight off the infection.

6.Medication side effects

Certain medications such as corticosteroids, immunosuppressants, and catecholamine vasopressors like dopamine can release enzymes in the blood that spike blood glucose levels and disrupt the release of insulin, thereby affecting the absorption of glucose from the bloodstream.

Patients kept on IV in hospitals also have a chance of developing hyperglycemia as the nutritional fluid contains sugar to restore electrolyte balance. Therefore, this should be carefully administered in patients who are recovering to prevent spikes in blood sugar levels.


Hyperglycemia is more commonly seen in people with a family history of diabetes. Although diabetes itself can be prevented through diet and lifestyle changes, impaired insulin sensitivity can be passed on and may make the person more susceptible to reactive hyperglycemia.


Excess fat in the body disrupts the balance of glucose and insulin. Excess fat cells, called adipocytes, release inflammatory proteins such as interleukins and increase the body’s resistance to insulin.

Adipocytes activate processes that disrupt the body’s ability to produce and release insulin when the blood sugar is high.

Adipocytes also decrease the ability to remove glucose from the bloodstream to be used as energy or stored as glycogen within the skeletal muscles.

Obesity, increased lipids, or fatty acids also activate pathways that impair insulin signaling within muscles.

9.Lifestyle factors – Diet and Physical Activity

Food plays an important role in the blood glucose levels of the body. An excessive amount of sugar and/or carbohydrates (including carbohydrate-containing foods) can raise blood glucose levels post meals as the food gets broken down into glucose molecules that enter the bloodstream.

In a healthy person, these glucose molecules get absorbed by the insulin released by the pancreas and then get transported to the muscles and liver for energy and storage.

As the blood sugar decreases, the pancreas is signaled to stop the production of insulin, stabilizing the blood glucose levels.

When blood sugar levels are continually elevated with repeated and excessive intake of carbohydrates and sugar, the excess glucose in the body stimulates the pancreas to release extra insulin.

Over time, the body develops a resistance to this chronic high blood sugar as the insulin stops responding and keeps the blood glucose levels high.

Excess alcohol consumption can also affect blood sugar levels by interfering with the liver’s ability to regulate the production and release of glucose. It negatively impacts the body’s response to insulin.

Physical Activity:
Skeletal muscles store extra glucose as glycogen for energy for later use. With low levels of physical activity, the muscles become inactive and cannot remove the excess glucose efficiently from the blood.

Why is it important to manage glucose rise?

It is imperative to manage non-diabetic reactive hyperglycemia because elevated glucose levels can

  1. Prevent healing,
  2. Increase the risk of infections,
  3. Cause irreversible damage to the nerves, blood vessels and organs such as eyes and kidneys,
  4. Increase the risk of heart attacks and strokes.

Four Ways to Prevent and Manage Reactive Hyperglycemia(Glucose Rise)

Multiple lifestyle changes that can be made to prevent and manage reactive hyperglycemia are

1.Exercise regularly

Regular exercise of at least 30 mins a day, 5 days a week, helps lower blood sugar levels, especially when the levels are high. Skeletal muscles store extra glucose as glycogen for energy for later use.

When you do moderate exercise, like walking, it makes your heartbeat a little faster and your breath a little harder.

Your muscles use more blood glucose thereby lowering your blood sugar levels over time. It also makes the insulin in your body work better.

The benefits last for hours after the workout. Over time, it can also stabilise your blood sugar.

For example- strength training can expand the storage capacity for blood sugar in the muscle and improve insulin sensitivity. Children with reactive hyperglycemia should get at least 60 minutes of physical activity each day.

2.Maintain a healthy weight

Maintaining a healthy weight can help prevent irregular insulin production and can absorb excess glucose from the blood optimally.

3.Limit alcohol intake

As mentioned before, the liver is a vital organ in regulating blood sugar levels. Alcohol initially leads to a spike in glucose level, which is generally metabolized speedily. Therefore, limiting the alcohol intake in both men and women can prevent reactive hyperglycemia.

4.Avoid smoking

Cigarettes, E-cigarettes, and smokeless tobacco contain nicotine and other chemicals that cause lung damage. These chemicals make it tough to regulate your blood sugar levels.


The hormone insulin controls the metabolism of carbohydrates, fats, and protein by advancing the absorption of glucose from the blood into the liver, fat, and skeletal muscle cells.

Glycogenolysis and gluconeogenesis, the sources of circulating glucose are partially under the influence of glucagon, another hormone produced in the pancreas.

A sudden drop in blood glucose levels in the body is referred to as hypoglycemia. Conversely, a sudden rise is called hyperglycemia.

Elevated glucose levels can prevent healing and amplify the risk of heart diseases among other detrimental factors. When the blood sugar level drops, the muscles and brain cells do not have enough energy to work well.

Exercise, moderate consumption of alcohol, and maintenance of a healthy weight are some of the ways to manage hyperglycemia. Reducing refined carb intake along with these factors is ideal for managing hypoglycemia.

Disclaimer: The contents of this article are for general information and educational purposes only. It neither provides any medical advice nor intends to substitute professional medical opinion on the treatment, diagnosis, prevention or alleviation of any disease, disorder or disability. Always consult with your doctor or qualified healthcare professional about your health condition and/or concerns and before undertaking a new health care regimen including making any dietary or lifestyle changes.


  1. Non-diabetic Hypoglycemia – Low Blood Sugar without Diabetes
  2. Blood Sugar Crash: Symptoms, Causes, and Treatment
  3. Hyperglycemia: What Is High Blood Sugar?
  4. Hyperglycemia: Causes, Symptoms, Treatments & Prevention
  5. Pancreas: Anatomy, Function, and Diagnosis

Subscribe to Metablog

Get the best, most science backed, and latest in metabolic health delivered to your inbox each week.

Thank you for subscribing!

Please check your email for confirmation message.

    You can unsubscribe at any time, no hard feelings. Privacy Policy

    Loading please wait...