The liver and muscles produce some blood sugar, but most of it comes from food and drinks that contain carbohydrates.
In order to keep blood sugar levels within a normal range, the body needs insulin. Insulin is a hormone that directs the body's cells to take up glucose and store it.
If there is not enough insulin, or insulin doesn't work properly, blood sugar builds up. High blood sugar levels can cause health problems.
What does this feel like, why does it happen, and how do you know if your blood sugar levels are too high? Read on to find out more.
High blood sugar can cause headache and fatigue.
Blood sugar is fuel for the body's organs and functions.
But having high blood sugar doesn't provide a boost in energy.
In fact, it's often the opposite, because the body's cells can't access the blood sugar for energy.
How does this feel?
When a person has high blood sugar, they may:
- have a headache and other aches and pains
- find it hard to concentrate
- be very thirsty or hungry
- feel drowsy or tired
- have blurred vision
- feel their mouth is dry
- have bloating
- need to urinate often
- notice that wounds take a long time to heal
High blood sugar and low insulin can lead to a rise in ketones, and possibly diabetic ketoacidosis (DKA), a serious complication that needs urgent medical attention.
If this occurs, the individual may experience:
- shortness of breath
- a fruity taste or smell on the breath
- a rapid heart beat
- confusion and disorientation
Testing kits for levels of blood sugar and ketone levels are available for purchase online, for use at home. However, you should see a doctor first, if you do not already have a diagnosis of diabetes.
How does high blood sugar affect the body?
High sugar in the blood can lead to a number of other symptoms and complications. Here are just a few.
Urination and thirst: High blood sugar goes into the kidneys and urine. This attracts more water, causing frequent urination. This can also lead to increased thirst, despite drinking enough liquids.
Weight loss: High blood sugar can cause sudden or unexplained weight loss. This occurs because the body's cells aren't getting the glucose they need, so the body burns muscle and fat for energy instead.
Numbness and tingling: High blood sugar can also cause numbness, burning, or tingling in the hands, legs, and feet. This is caused by diabetic neuropathy, a complication of diabetes that often occurs after many years of high blood sugar levels.
Over time, the body's organs and systems can be harmed by high blood sugar. Blood vessels become damaged, and this can lead to complications, including:
- heart attack or stroke
- damage to the eye and loss of vision
- kidney disease or failure
- nerve problems in the skin, especially the feet, leading to sores, infections, and wound healing problems
Gestational diabetes can occur during pregnancy.
There are several types of diabetes.
In type 1 diabetes, the immune system attacks the cells in the pancreas that produce insulin. As a result, the body lacks insulin and blood sugar levels rise.
People with type 1 diabetes must take insulin through a needle, pen, or insulin pump to keep blood sugar levels under control.
Only 5 percent of all people with diabetes have type 1, according to the American Diabetes Association.
In type 2 diabetes, the body does produce insulin but is unable to use it properly. The pancreas tries to make more insulin, but often cannot make enough to keep blood sugar levels under control. This is known as insulin resistance.
People with type 2 diabetes may need to take insulin, pills, or make diet or exercise changes to help control blood sugar levels.
Gestational diabetes can happen when insulin resistance and high blood sugar levels appear during pregnancy. This must be monitored throughout pregnancy, as it can lead to complications for the mother and the baby. Gestational diabetes usually goes away after delivery.
Cystic fibrosis: Diabetes can also be linked to this condition.
Hyperglycemia refers to a blood sugar level that is higher than normal. Diabetes is the main cause, but people who take beta blockers and certain steroids may also experience high blood sugar.
Risk factors for high blood sugar
The exact cause of type 1 or type 2 diabetes is not known. Some factors may make a person more likely to develop these conditions, however.
Type 1 diabetes
Researchers believe certain genetic or environmental factors may make people more likely to get type 1 diabetes. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) say certain genes play a role, and other factors such as viruses and infections may also be involved.
The Juvenile Diabetes Research Foundation say that there is nothing a person can do to prevent type 1 diabetes, and it is not related to eating, exercise, or other lifestyle choices. Type 1 diabetes usually begins during childhood or early adulthood.
Type 2 diabetes
No single factor has been identified, but the following risk factors make developing type 2 diabetes more likely:
- having certain genes that are linked to diabetes
- being overweight or inactive
- having a parent or sibling with type 2 diabetes
- having African-American, Alaska Native, American Indian, Asian-American, Hispanic, or Pacific Islander ethnicity
- being aged over 45 years
- receiving treatment for high blood pressure, or having blood pressure of 140/90 or higher
- having low levels of "good" HDL cholesterol or high levels of triglycerides
Healthy blood sugar
Regular blood sugar testing can help people with diabetes keep their blood sugar levels under control.
People who have high blood sugar should discuss their target levels with their doctor.
Regular testing may be needed to find out if these are within a healthy range. Each individual is different and levels can vary from person to person.
To determine a person's blood sugar levels, blood tests may be taken after not eating for 8 hours, 2 hours after a meal, or at both times.
Some people may also take a glucose tolerance test, which requires the patient to drink a sugary liquid and get blood tests afterward.
The American Diabetes Association recommend a pre-meal blood sugar level of 80-130 milligrams per deciliter. Around 1 to 2 hours after the beginning of a meal, blood sugar should be less than 180 milligrams per deciliter.
The American Association of Clinical Endocrinologists (AACE) state that blood sugar should be below 110 milligrams per deciliter after fasting.
Around 2 hours after eating a meal, the AACE recommend a blood sugar target of fewer than 180 milligrams per deciliter.
Controlling blood sugar levels
Many people with diabetes must check their blood sugar levels daily with a glucose meter. This device takes a drop of blood, usually from a finger, and displays the sugar level within a few seconds.
People with type 1 diabetes will need to take insulin as directed, usually several times a day. Those with type 2 diabetes or gestational diabetes may need to change their diet and exercise habits. They may also need to take oral medications or insulin.
Blood sugar is only one part of a healthy lifestyle with diabetes.
A person should also have their cholesterol and blood pressure checked regularly to help avoid heart disease.
In addition, people with diabetes should check their feet regularly for sores or other problems and should receive regular eye exams.
Preventing high blood sugar
Monitoring your diet and exercise alongside blood sugar levels can help you maintain a healthy blood sugar level.
Eating a balanced diet, getting regular exercise, and maintaining a healthy weight can reduce the risk of type 2 diabetes. There is no way to prevent type 1 diabetes.
A number of strategies can help prevent hyperglycemia.
- Ensure you check your blood sugar levels as advised by your doctor and take the correct amount of insulin, if you have type 1 diabetes.
- Speak to your health care provider or dietitian about which foods to eat or avoid, and how much to eat, how often.
- Take precautions to avoid infections, for example, regular hand washing.
- Plan your food intake and exercise to balance blood sugar levels.
- As far as possible, minimize stress, for example, through exercise, getting enough sleep, and stress-reducing activities such as meditation or yoga.
Low blood sugar
Low blood sugar, or hypoglycemia, is often a side effect of diabetes medicines. Taking too much insulin can result in low blood sugar levels.
Hypoglycemia can also be caused by some other medications, health conditions, or skipping meals.
Symptoms of low blood sugar may include:
- feeling weak or shaky
- sudden nervousness, anxiety, or irritability
- sweating or chills
- extreme hunger
- fast heart rate, or palpitations
Low blood sugar can often be corrected by drinking a beverage that contains carbohydrates.
Frequent episodes of low blood sugar should be discussed with a doctor.
Diabetes medications may need to be changed or reduced in order to correct the problem.
When to see a doctor
Symptoms such as tiredness, increased thirst, frequent urination, or weight loss should be discussed with a doctor. These could be signs of diabetes or other health problems.
Most checkups will involve blood sugar testing, even if the person has no symptoms. The U.S. Preventive Services Task Force recommend that adults age 40 to 70 who are overweight should be tested for diabetes. Those who have a family history of diabetes or who have other risk factors may need earlier or more frequent tests.
A person's health and well-being depend upon proper management of blood sugar levels. Regular visits to the doctor and following diet, exercise, and medication guidelines can help control blood sugar for a better quality of life.
Anyone who has diabetes should carry a medical ID with them, especially if they use insulin, as this can provide important information in case of an emergency.
The American Diabetes Association note that IDs are now available with a compact USB drive that can contain a full medical record.