Hyperglycemia Symptoms

Hyperglycemia (high blood sugar) can come on gradually in people with type 2 diabetes. In the early stages, symptoms of high blood sugar like feeling more tired than usual and being extra thirsty can be mild and you may not notice them. Some people do not recognize they have hyperglycemia symptoms for years.

However, high blood sugar that becomes chronic can harm your blood vessels and lead to health problems that affect your eyes, heart, kidneys, and feet.

This article covers the symptoms of high blood sugar. It also goes over the complications of uncontrolled hyperglycemia and when to see a healthcare provider about your symptoms. 

Signs and Symptoms of Hyperglycemia

In the beginning stages of hyperglycemia, the symptoms can be so mild that people do not realize they're having telltale diabetes warning signs. In fact, that's one reason why many people have undiagnosed diabetes.

If you have already been diagnosed with diabetes and are having these symptoms, it could be a sign that your treatment needs to be adjusted, so you’ll want to talk to your provider. 

Excessive Thirst (Polydipsia)

One of the most important jobs your kidneys do is keeping your blood sugar levels in check. Usually, your kidneys filter extra glucose from your blood and reabsorb it, so your urine should have little to no glucose in it.

If you are hyperglycemic, this process becomes much more difficult on your kidneys. They will need to work overtime to absorb the excess glucose. To keep your blood sugar in balance, your kidneys have to pull fluids from your tissues to water down (dilute) the sugar and excrete more glucose into your urine.

The more fluids your tissues lose, the stronger your urge to drink will be. If you find that no matter how much you drink, you still feel very thirsty or like your mouth is severely dry, it can be a sign of hyperglycemia.

Increased Urination (Polyuria)

More frequent trips to the bathroom, especially at night, can be a sign of high blood sugar. This happens because your kidneys are drawing extra water out of your tissues to dilute the extra sugar in your blood and get rid of it through urine.

Increased Hunger (Polyphagia)

When there's extra sugar in your bloodstream, it means that your body cannot use it for fuel. Your cells end up starved of energy, which causes you to feel more hungry than usual. However, what you eat matters because the more carbohydrates you consume, the higher your blood sugar will be.

Blurry Vision

High sugar levels force the body to pull fluid from your tissues, including the lenses of your eyes. This can affect your ability to focus on what you're looking at and may lead to blurry vision.

Fatigue

Normally, your cells absorb blood sugar for energy. When sugar stays in the blood instead of being taken to your cells, your cells don't have enough. This can make you feel sluggish or fatigued—especially after you’ve eaten a high-carb meal.

Infections

If your immune system is not working well as a result of high blood sugar and stress on the body, you might be more likely to get infections. It’s also thought that some kinds of bacteria actually live best in high-sugar environments, so they might thrive in your body when your levels are high.

Since yeast feeds on sugar, having elevated blood sugar levels can lead to an overgrowth of yeast. For people with a vagina, frequent yeast infections are common if they have high blood sugar levels.

Erectile Dysfunction and Fertility Effects

People with a penis who have diabetes are three times more likely to develop erectile dysfunction than people with a penis who do not have diabetes. One reason why this may happen is that hyperglycemia damages the blood vessels that are needed to get or maintain an erection.

High blood sugar levels can also affect fertility and can complicate pregnancy. Hyperglycemia in pregnancy can be particularly damaging to a pregnant person and fetus.

According to the ADA, uncontrolled diabetes in pregnancy carries risks like:

• Spontaneous abortion (loss of pregnancy before 20 weeks)
• Fetal anomalies (problems with fetal development during pregnancy)
• Preeclampsia (uncontrolled blood pressure in the pregnant person)
• Fetal demise (delivery of a deceased fetus)
• Macrosomia (large baby)
• Hypoglycemia (low blood sugar) in babies at birth
• Neonatal jaundice (a liver condition that causes yellowing of the newborn's skin and eyes)

In addition, diabetes in pregnancy may increase the risk of obesity and type 2 diabetes in offspring later in life.

ADA guidelines for people with diabetes emphasize the importance of preconception counseling. It should address the importance of achieving glucose levels as close to normal as is safely possible—ideally A1C <6.5% (48 mmol/mol). This is very important to reduce the risk of serious complications in both the pregnant person and the developing fetus.

Skin Conditions

Dry, itchy skin, and wounds or cuts that are slow to heal can be a sign of hyperglycemia. Another sign that points to insulin resistance is acanthosis nigricans, a condition in which thick, velvety patches form in the folds or creases of areas like the neck.

Mental Health

Researchers also think it’s possible that your blood sugar levels might affect your mood. While more research is needed, there is some evidence that higher blood sugar levels after meals in people with type 2 diabetes might be linked to certain negative mood symptoms, like irritability.

Other studies have suggested that having higher blood sugar levels might be linked to feelings of anger and sadness among people with diabetes.

Severe Symptoms

There are also symptoms that tend to occur when someone has had hyperglycemia for a long time, or when their blood sugar is extremely elevated. These symptoms are more severe and long-lasting and can be a sign that a person needs medical care right away. 

Stomach Pain

Chronic hyperglycemia can lead to nerve damage in the stomach (gastroparesis or delayed gastric emptying). This condition can cause nausea and very slow digestion. Stomach pain can also be a sign of diabetic ketoacidosis, a medical emergency that needs to be treated right away.

Weight Loss

Unintentional weight loss is an important sign of elevated blood sugar, particularly in kids who are drinking and urinating often. Many children diagnosed with type 1 diabetes lose weight before they’re diagnosed because their bodies cannot use the sugar in the bloodstream for fuel.

Numbness

Nerve damage in the extremities (peripheral neuropathy), can happen over time in people with high blood sugar. It causes symptoms like numbness, tingling, or pain in the hands, feet, or legs.

Hyperglycemic Hyperosmolar Nonketotic Syndrome

Hyperglycemic hyperosmolar nonketotic coma (HHNKC) is a very serious complication of high blood sugar in people with type 1 or type 2 diabetes. It most often occurs in people who are non-insulin dependent (type 2 diabetes).

Signs and symptoms include:

• Extreme thirst
• Confusion
• Fever (usually over 101 degrees)
• Weakness or paralysis on one side of the body

The best way to prevent HHNKC is to take your medications as directed and contact your healthcare team when your blood sugar is consistently over 300 mg/dL.

Diabetic Ketoacidosis

Hyperglycemia can lead to another dangerous condition called diabetic ketoacidosis (DKA). This condition most commonly occurs in people who have type 1 diabetes.

DKA happens when the body has little or no insulin to use. As a result, blood sugars rise to dangerous levels, and the blood becomes acidic. This leads to cell damage. If it continues to progress, DKA can cause a person to fall into a coma or die. 

DKA needs immediate medical attention. People with DKA need to be monitored by a medical team and given intravenous fluids, electrolytes, and insulin.

Like hyperglycemia, DKA tends to develop slowly. The first symptoms are usually intense thirst and excessive urination. If left untreated, more severe symptoms can come on quickly and may include:

• Fast, deep breathing
• Dry skin and mouth
• Flushed face
• Fruity-smelling breath
• Headache
• Muscle aches and stiffness
• Being very tired
• Nausea and vomiting
• Stomach pain

Complications

Chronic hyperglycemia can lead to a host of complications known as micro (small) and macro (large) vascular issues. They include damage to the:

• Eye (retinopathy)
• Kidney (nephropathy)
• Peripheral and autonomic neuropathy (nerve loss in the feet and other areas of the body such as the intestine)

Additionally, chronically elevated blood sugars can cause or worsen heart disease and peripheral arterial disease, in which narrowed arteries reduce blood flow to the arms and legs.

When to See a Healthcare Provider

If the symptoms are more severe (like those of DKA), do not wait to call your provider. Go to the ER right away or call 911.

If you already know that you have diabetes, you may be checking your blood sugar levels regularly. If you’re having symptoms of high blood sugar, test your levels to see what they are.

If your blood sugar is high and it’s just a one-time thing, you might be able to manage it on your own by going for a walk or doing some light exercise, drinking extra water, and taking your medication as prescribed. However, if you notice elevated blood sugar for several consecutive days, give your medical team a call. It can be a sign that your treatment is not working well for you. 

If you have not been diagnosed with diabetes but you’re having symptoms of high blood sugar, you should talk to your provider. If you are overweight or obese, or have a family history of diabetes, it’s important to get screened for diabetes. 

You can start getting complications from untreated diabetes before you’re diagnosed, so the sooner you can get diagnosed and start treatment the better. 

If you've noticed that your child is drinking, eating, and urinating more often, you should make an appointment with their provider—especially if you've seen a quick change in their weight. If your child has symptoms of hyperglycemia and their blood sugar is over 240 mg/dL, they need to be tested for ketones. If the test is positive and their ketone levels are high, you might need to take them to the ER.

Summary

Hyperglycemia (high blood sugar) is an early warning sign of diabetes. It causes symptoms like excessive thirst and hunger, increased urination, and fatigue.

Hyperglycemia symptoms tend to come on gradually and may go unnoticed until more serious complications develop. Left untreated, high blood sugar can damage blood vessels and nerves and may eventually harm the eyes, heart, kidneys, and feet.

If you’re having symptoms of high blood sugar, it’s best to see your provider—whether you already have been diagnosed with diabetes or not. The sooner you can start treatment, the better in terms of avoiding the serious health consequences of untreated diabetes and high blood sugar.