What is type 1 diabetes?
Type 1 Diabetes is an autoimmune disease. That means that the body mistakenly destroys healthy tissues or cells. In Type 1 Diabetes, beta cells are destroyed. These are the cells in the pancreas that make insulin. As a result, the pancreas produces little to no insulin. Insulin is a hormone that helps our bodies move sugar (also called glucose) into our cells to be used for energy. Without insulin, glucose builds up in the bloodstream, causing hyperglycemia, or high blood glucose levels.
People with type 1 diabetes must take insulin daily. If left untreated, the excess glucose in the blood can cause damage to many different parts of the body over time.
Causes
If your child is diagnosed with type 1 diabetes, it’s important to understand that there is nothing you could have done to prevent it.
The exact cause of type 1 diabetes is not known. There may be an environmental cause and/or a genetic link, as autoimmune conditions can sometimes be seen in families. Until recently, it was not possible to stop the progression of type 1 diabetes. However, if caught early enough, new treatments can delay the progression of diabetes. (See “Early Stages of Type 1 Diabetes and Screening for Siblings,” below.)
The difference between type 1 and type 2 diabetes
High blood sugars occur in both type 1 and type 2 diabetes. The difference is with each type’s causes and treatments.
Type 1 diabetes is an autoimmune disorder that makes the pancreas unable to produce insulin. Without insulin, blood glucose levels rise. Because people with type 1 diabetes do not make insulin, they must take insulin every day to control their blood sugar.
Type 2 diabetes is a metabolic disorder where the pancreas can produce insulin, but the cells in the body are resistant to insulin. Blood glucose levels rise when the insulin resistance is such that the pancreas cannot produce enough insulin to effectively manage blood glucose levels. So, being resistant to insulin and not making enough insulin both lead to high blood glucose levels.
Type 2 diabetes is the most common type of diabetes, accounting for 90%-95% of cases. It typically occurs in adults, though more children are developing this type as well.
People with obesity or who are overweight and those from certain racial and ethnic backgrounds are more likely to develop type 2 diabetes. Type 2 is often attributed to genetic predisposition and lifestyle factors such as a lack of regular exercise and eating a diet high in sugar, fats and processed foods.
Because many people with type 2 diabetes still make insulin, they can be treated with non-insulin oral or injectable medications that help their body to make more insulin and/or respond more effectively to the insulin they are already making. If these medications cannot control blood sugars, people with type 2 diabetes sometimes need insulin.
Type 1 diabetes has no cure and requires lifelong management with insulin. The effects of type 2 diabetes can often be controlled with medication and even reversed by adopting a healthier lifestyle – eating a balanced diet, increasing physical activity and maintaining a healthy weight.
Signs and symptoms
Type 1 diabetes often appears suddenly during childhood, adolescence, and even adulthood. Each child may experience symptoms differently, but the most common symptoms are:
- Increased and significant thirst
- Increased urination (babies may need very frequent diaper changes and toilet-trained children may start wetting themselves and/or wetting the bed more often)
- Dehydration
- Increased appetite, but weight loss instead of gain
- Blurred vision
- Abdominal pain
- Persistent nausea and vomiting
- Excess drowsiness or fatigue
Testing and diagnosis
Type 1 diabetes is commonly diagnosed in childhood and adolescence, but it can be diagnosed at any age. If you or your doctor suspects type 1 diabetes, your child’s doctor will order various tests to confirm the diagnosis. These may include:
- Hemoglobin A1c. The A1c blood test measures your child’s average blood glucose level over the previous 3 months. An A1c below 5.7% is normal; between 5.7% and 6.4% is in the prediabetes range, and 6.5% or higher indicates the presence of diabetes.
- Diabetes autoantibody panel. These blood tests look for the presence of specific autoantibodies, which indicate that your child’s body is attacking the cells that make insulin. Autoantibodies are found in children with type 1 diabetes but not in children with type 2. Common diabetes autoantibodies include: GAD65, IA-2, ICA, ZnT8, and insulin antibodies.
- Urine or Blood test for ketones. When there is not enough insulin around for cells to take up glucose and use it for energy, the body burns fat for energy, which generates ketones. Although ketones provide a good source of fuel, they are also acids and can lead to problems in the body when levels get too high.
- Fasting blood glucose test. This blood test measures your child’s glucose levels after an overnight fast of at least eight hours. A fasting blood glucose level of 99 mg/dL or lower is in the normal range; 100 to 125 mg/dL falls in the prediabetes range; and 126 mg/dL or greater indicates the presence of diabetes.
- Oral glucose tolerance test. This test measures blood glucose at timed intervals before and after your child drinks a liquid high in glucose. The procedure begins with a fasting blood glucose test, then your child drinks the high-glucose liquid. Blood glucose levels are then checked multiple times for up to 3 hours after ingesting the drink. The goal is to see how effectively the body processes a large glucose load.
If these tests confirm type 1 diabetes, treatment must begin immediately.
Treatments
If your child is diagnosed with type 1 diabetes, they typically will require a brief hospital stay while we work to develop a treatment plan to help control their blood glucose levels. Your child will need to take daily insulin injections to replace the insulin their body no longer makes on its own. A healthy diet and regular exercise also help control blood glucose levels.
The specific treatment plan for type 1 diabetes will be determined by your child's diabetes team. Here are the typical elements of long-term diabetes treatment and management:
- Regularly checking blood sugars. Keeping blood glucose levels within a target range and checking glucose levels frequently is an important part of managing diabetes. The results help you and your child make decisions about insulin, food, and activity. The traditional approach to monitoring blood glucose levels uses a drop of blood on a testing strip inserted into a meter (glucometer).
- Continuous glucose monitor (CGM) is a more recent technology that uses a sensor just under the skin to measure glucose levels every one to five minutes. CGM glucose levels are sent to a receiver or smartphone that shows the glucose levels, whether glucose levels are rising or falling, and can provide optional alerts and alarms for high and low glucose levels. Whether your child uses fingersticks or a CGM, diligent record keeping of glucose results and insulin dosing goes a long way to successfully keeping blood glucose levels under control and helps your child's medical team provide the most responsive care.
Administering insulin. People with type 1 diabetes make little to no insulin and so insulin is the mainstay of treatment. We try to deliver insulin in a way that closely mimics how a normally functioning pancreas works. Insulin cannot be taken orally and must be given as an injection because stomach acids destroy this delicate protein. Two main types of insulin are used: Long-acting (basal) insulin and fast-acting (bolus) insulin:
- Basal insulin is usually given once a day, lasts about 24 hours, and is intended to keep glucose levels steady when your child isn't eating or being active. At mealtimes, your child's body will produce more insulin to help use the food they've eaten for energy.
- Bolus insulin is given to cover the carbohydrates eaten (see below) and bring high blood sugars back into the target range.
In a day, most children with diabetes will need 1 basal insulin injection and at least 3 fast-acting insulin injections, or possibly more depending on how frequently they eat.
- Insulin pumps are a wearable technology that contains only fast-acting insulin. These devices give a small amount of background insulin throughout the day to replace basal insulin. When eating, the pump can administer insulin in a bolus to cover the carbohydrates eaten and treat elevated blood glucose levels. The pump can calculate how much insulin you need to cover the carbohydrates eaten and lower a high glucose level back to the target range. The site where the pump is connected to your body is changed once every 3 days.
- The latest insulin delivery systems, called Automated Insulin Delivery (AID), combine CGM and insulin pump technologies. AID systems use CGM data to automatically increase or decrease insulin delivery through the pump, in an effort to keep glucose levels in range while decreasing some of the work of managing diabetes!
- Planning meals and counting carbohydrates. Understanding how food affects the body’s blood sugar will help you develop a meal plan for your child that keeps their blood glucose levels within the target range. This does not mean eliminating carbohydrates from their diet entirely – kids need carbs for energy and growth. Eating a mix of healthy carbs, lean proteins, and fats is a great way to successfully manage blood glucose levels. CHOP has resources with advice for how to “count carbs,” schedule meals, and adjust insulin dosing based on diet.
- Planning for exercise. Exercise helps the body use insulin better. It helps to control weight and keep blood glucose levels in the target range. And it keeps your heart healthy. Doctors recommend that everyone get at least 30 to 60 minutes of physical activity each day. Children with type 1 diabetes have individualized responses to exercise – their blood glucose levels may go up or down. When your child starts a new sport or physical activity, you may need to check glucose levels more often to monitor the effect of the activity. Kids should have a kit ready with juice, sports drinks, or glucose tablets to treat low blood sugar. Coaches, teachers, or other supervising adults should know how to recognize, treat and prevent low blood sugar for your child. Your medical team will have more information about how to manage your child’s exercise and insulin routine.
- Checking for ketones as needed. When there is not enough insulin around for cells to take up glucose and use it for energy, the body burns fat for energy, which generates ketones. Ketones develop during times of illness – especially illnesses associated with vomiting, diarrhea and not eating enough. Checking for urine or blood ketones when your child has one of these illnesses is very important because we will need to adjust your child’s diabetes management to help clear the ketones and prevent diabetic ketoacidosis.
- Helping your child cope with and take responsibility for their health. Type 1 diabetes is a challenging diagnosis and can take an emotional toll on your child. However, there are many ways to help your child cope with the reality of managing this lifelong condition. Staying positive and designing a regimen that fits their lifestyle will help them feel more in control of their condition. As they get older, they will learn to read their body’s signals and manage their blood glucose and insulin levels successfully. The goal of the Diabetes Center is to provide the support needed to help you and your child manage this condition with confidence.
- Partnering with your child’s school and other caregivers to manage diabetes. Make sure that adults who spend time with your child – including teachers, coaches, the school nurse, grandparents, other family members, and sitters – know about your child’s diabetes and how they can help intervene when blood glucose may be too high or low. Your child should also wear a medical alert necklace or bracelet, so the information is readily available to medical providers in case of emergency.
- Problem solving for blood glucose levels to keep diabetes under control. Managing diabetes means being constantly responsive to changes in blood glucose levels. Keep detailed logs of glucose levels and insulin dosing, the foods eaten, exercise and illness, and stay in close touch with your medical team to help you manage the (literal) highs and lows.
Your Child's Diabetes Center Appointment
Learn what to expect at an appointment with the Diabetes Center for Children at CHOP and what to bring to your child’s visits.
Follow-up care
Regular diabetes check-ups are needed at least every three months. These visits help you and the diabetes team take the best care of your child. Research has proven that children and teens with diabetes who see their diabetes team on a quarterly basis (four times per year) have better average blood glucose, fewer hospitalizations, and healthier outcomes than children who only come once or twice a year.
People with type 1 diabetes (an autoimmune disorder) often have an increased risk of developing other autoimmune disorders. Certain thyroid diseases such as chronic lymphocytic thyroiditis, more commonly known as Hashimoto’s disease, affect the production of thyroid hormones that regulate the body’s metabolism. With celiac disease, the gastrointestinal system is unable to digest gluten, and this affects the body’s ability to absorb nutrients. Periodic screening tests should identify these issues if they develop.
Once a year, your child will have extra screening tests to look for early signs of complications and other conditions that occur more commonly in people with diabetes. These tests include:
- Dilated eye exam for diabetic retinopathy (after 3-5 years of diabetes)
- Urine test for albuminuria (after 5 years of diabetes)
- Blood lipid profile for high cholesterol (once between 2 and 10 years old, beginning again at 10 years)
- Thyroid function tests (every 1-2 years)
- Celiac panel (every 2-5 years)
Complications of type 1 diabetes
It's important that you know that children with diabetes are at risk for developing complications and associated problems. There are things you and your child can do though to help prevent these issues. And we're here to help you every step of the way. At each visit to the Diabetes Center, your child is screened for:
- Growth problems based on height, weight, BMI
- High blood pressure
- Foot problems and changes in sensation
Occasional high blood glucose levels will not cause complications, and effective blood glucose management over the long term goes a long way to preventing many associated complications. But high blood glucose levels over a long period increase the risk that your child will have diabetes-related complications that can cause problems with eyes, feet, kidneys, nerves, and heart.
Among the long-term complications of type 1 diabetes are:
- Heart disease. Over time, higher levels of blood glucose can damage blood vessels and nerves that affect the heart. And people with diabetes are more likely to develop conditions such as high blood pressure and high cholesterol which are risk factors for heart disease.
- High blood pressure (hypertension). About half of adults with diabetes have high blood pressure. Untreated high blood pressure increases the risk of heart, eye, and kidney disease. Ways to manage your child’s blood pressure include maintaining a healthy weight, encouraging regular physical activity, and keeping them away from smoking and second-hand smoke. High blood pressure can also be treated with medicine.
- High cholesterol (hyperlipidemia). Cholesterol is a type of fat in your blood and in all of your body’s cells. Some cholesterol is needed in your body, but too much in the blood is unhealthy. Having diabetes and high cholesterol increases the risk for heart disease. Some kids may need medicine to lower their cholesterol, but good blood glucose management can usually prevent high cholesterol. To help your child keep their cholesterol low, talk to a dietician about a heart-healthy meal plan that works with their diabetes, encourage them to exercise for at least 30 minutes each day, and help them avoid smoking or second-hand smoke.
- Gum disease (periodontitis). High blood sugar helps germs grow in your mouth and on your teeth. These germs can cause cavities. They can also cause gums to become red, sore, and swollen. Gums may bleed when brushing teeth. Good blood glucose control can help prevent gum disease. To maintain good oral health, children should brush their teeth after meals and snacks with a soft toothbrush, and floss once a day. Make sure your child sees the dentist 2 times a year and tell the dentist about your child’s diabetes.
- Eye damage (diabetic retinopathy). Diabetes affects the small blood vessels in the back of the eye (retina). The vessels can get weak and may break. This causes vision problems if not treated. Eye disease is not common in children. Good blood glucose management can help prevent eye disease. Make sure your child has a yearly check-up with an eye doctor. With early detection and treatment, eye damage can be prevented. Retinopathy is treated with laser therapy which is safe and painless.
- Kidney disease (diabetic nephropathy). The function of the kidneys is to clean the blood. Kidney disease happens when the kidneys cannot clean the blood as effectively as before. Small amounts of protein leak into the urine. This is called microalbuminuria (micro = small, albumin = protein, uria = urine). A urine test called Microalbumin to Creatinine Ratio can help us identify early signs of kidney disease. When we see signs early on, we can start treatment to prevent more damage and sometimes even reverse damage. Good blood glucose control can help prevent kidney disease.
- Foot problems (diabetic neuropathy). Foot problems are rare in children with diabetes. Most children have normal circulation and normal feeling in their feet. A cut on the foot should heal quickly. As with other complications, good blood glucose management can help prevent foot problems. Adults with diabetes may have diabetic neuropathy, or nerve damage from diabetes. When the nerve is damaged, it is less or more sensitive to touch. Adults may get foot problems because they have poor circulation and poor feeling in their feet. They may not feel a cut on their foot. If the cut gets infected, it is hard for it to heal. Your child’s feet will be checked by your diabetes provider once a year or if you see problems.
Early Stages of Type 1 Diabetes and Screening for Siblings
The information presented on this page has addressed what is called Stage 3 type 1 diabetes. However, earlier stages of type 1 diabetes occur before people develop symptoms. (This helpful graphic from Type 1 Diabetes TrialNet illustrates the early progression of the disease.)
Although the exact cause of type 1 diabetes is unknown, there is a genetic link, and some people are at higher risk for getting type 1 diabetes than others. Everyone who develops type 1 diabetes has these higher risk genes. Whereas the risk for type 1 diabetes in youth is about 1 in 400, the risk for type 1 diabetes is 15x higher (about 1 in 25) for people who have an immediate family member with type 1 diabetes.
In “Stage 1” type 1 diabetes, a person has at least two antibodies against the pancreas, but has completely normal blood glucose levels. In “Stage 2” type 1 diabetes, these antibodies cause enough damage to the pancreas that blood glucose levels are slightly elevated, but the patient still does not have symptoms of diabetes. Stage 2 type 1 diabetes is diagnosed based on the results of oral glucose tolerance testing. In “Stage 3” type 1 diabetes, the damage to the pancreas continues to increase, symptoms of diabetes develop, and treatment with insulin is needed. Everyone who has multiple positive antibodies against the pancreas will develop diabetes at some time in their life.
Until recently, it has not been possible to stop the progression of type 1 diabetes from stage 2 to stage 3. In 2023, the United States Food and Drug Administration (FDA) approved a medication called teplizumab (Tzield). When teplizumab is given to children with Stage 2 type 1 diabetes as a 14-day IV treatment, it can delay the need for insulin by 2 to 3 years on average. Talk to your child’s diabetes care team about having his or her siblings screened for diabetes with a simple blood test. This can be done with your child’s pediatrician through your healthcare insurance or as part of a research study.
Tools to Manage Diabetes
These resources will help your child and family manage blood sugar testing, highs and lows, insulin, nutrition, and more.
Life With Diabetes
These resources will help your family and child navigate life with diabetes, and the common challenges associated with the condition. Review our information about support and coping, school, teen topics, and general well-being.
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