Type 1 Diabetes

Medically Reviewed by Jabeen Begum, MD on April 19, 2024
11 min read

Type 1 diabetes is a condition in which your immune system destroys insulin-making cells (beta cells) in your pancreas. That means your body can't make enough insulin or any at all.

Insulin is a hormone that helps move glucose (sugar) from your blood and into your cells so it can be used for energy.

Because type 1 diabetes is often diagnosed in kids and young adults, it used to be called juvenile diabetes. In the past, it was also called insulin-dependent diabetes.

Are you born with type 1 diabetes?

You can get it at any age. In fact, half of all people now diagnosed with type 1 diabetes are adults.

Type 1 diabetes vs. secondary diabetes

A condition called secondary diabetes is like type 1, but your insulin-making cells are wiped out by another health condition or an injury to your pancreas, rather than by your immune system.

Type 1 diabetes vs. type 2 diabetes

If you have type 1, your body doesn't make enough insulin. With type 2 diabetes, your body can make insulin but can't use it well. The cells in your muscles, fat, and liver build up what's called insulin resistance.

With type 1 diabetes, you need to use man-made insulin every day so your body can function. But not everyone with type 2 diabetes needs it. Other medications can help you manage the condition.

No matter which type of diabetes you have, you'll need to keep a close eye on your daily habits, such as what you eat and how much activity you get to stay healthy.

Symptoms can come on very quickly. They include:

  • Extreme thirst
  • Increased hunger (especially after eating)
  • Dry mouth
  • Upset stomach and vomiting
  • Frequent peeing
  • Unexplained weight loss (despite eating and often feeling hungry)
  • Feeling tired or weak for no reason
  • Vision changes
  • Heavy, labored breathing (your doctor may call this Kussmaul respiration)
  • Repeated infections of your skin, urinary tract, or vagina
  • Mood changes

Late-onset type 1 diabetes symptoms

More research is being done on what's called Latent Autoimmune Diabetes in Adults (LADA). Some people refer to this as "Diabetes 1.5" or "Diabetes 1 1/2" because it overlaps with parts of both type 1 and type 2 diabetes.

LADA symptoms can come on very slowly, making it tricky to diagnose. So does the fact that people who have it are usually at a healthy weight, and often between the ages of 30 and 50 years.

Your child is at higher risk of type 1 diabetes if:

  • They're aged 4-6 years or 10-14 years.
  • Another family member also has it.

Type 1 diabetes symptoms in children

The signs are the same as for adults, but you may also notice:

  • More diaper changes for a baby
  • Diaper rash that doesn't get better when treated
  • Bed-wetting in kids who are potty-trained
  • Fast breathing
  • Belly pain
  • Throwing up
  • Behavior changes
  • Fruity-smelling breath

In some babies or kids, type 1 diabetes can also look like the flu.

If you notice any of these symptoms, take your child to the doctor.

Experts aren't sure what causes your pancreas to stop making insulin for your body. Your genes and immune system both appear to play big roles.

Is type 1 diabetes genetic?

To an extent, yes.

  • If you're assigned male at birth (AMAB) and have type 1 diabetes, there's a 1 in 17 chance that your child will have it, too.
  • If you're assigned female at birth (AFAB) and have type 1 diabetes, your child's risk is 1 in 25 if they were born before you turned 25, and 1 in 100 if they were born after your 25th birthday.
  • If both you and your partner have type 1 diabetes, the chance that your child will have it as well could be as high as 1 in 4.

Once you inherit genes that put you at risk for type 1, an environmental trigger such as an infection, virus, or autoimmune disorder, seems necessary to "switch" them on.

When scientists look at the blood of people with type 1, they can see special proteins that show their immune system is going after their pancreas.

Only about 5%-10% of people with diabetes have type 1. The risk factors for it aren't as clear as they are for type 2 diabetes. 

So far, experts only know that you’re more likely to have it if you:

  • Are younger than 20
  • Are white
  • Have a parent or sibling with type 1
  • Have extra weight

If your doctor thinks you have type 1 diabetes, they’ll check your blood sugar levels. This can be done in a few different ways.

A1c test. Also called a glycated hemoglobin test, it can figure out your average blood sugar levels over the past 3 months with one small blood sample. It does that by counting the number of hemoglobin (red blood) cells that are sticky with glucose. 

If your A1c result is 6.5% or higher, you'll retake the test. If it's the same number or higher, you likely have diabetes.

This test may not give you a correct result if you have any of the following:

  • Pregnancy
  • Kidney failure
  • Liver disease
  • Severe anemia
  • Blood loss
  • Some blood disorders, such as sickle cell anemia
  • Certain medicines, such as HIV drugs, in your system

If you're of African, Mediterranean, or Southeast Asian descent, you could also have a different type of hemoglobin (called a hemoglobin variant) that could skew your A1c result. Let your doctor know if any of these apply to you. If so, they can test your blood sugar in different ways, such as 

Fasting blood sugar test. In this test, your blood's taken after you haven't eaten overnight. A result of 126 milligrams per deciliter (mg/dL) or higher on two separate tests signals diabetes.

Random blood sugar test. Your blood glucose can also be checked at a random time. Whether or not you've recently eaten, a result of 200 mg/dL or higher means diabetes.

Type 1 diabetes test

The above tests can show whether you have diabetes, but they can't tell you which type. To find out whether you have type 1 or type 2 diabetes, your doctor will need to look for:

Autoantibodies. These are the proteins in your immune system that attack healthy cells, such as beta cells in your pancreas that make insulin. If you have type 1 diabetes, they'll show up in a blood sample.

Ketones. When you have type 1, your body relies on acids called ketones for fuel because it doesn't have enough glucose to use. A urine (pee) test can detect them.

Across the U.S., type 1 diabetes is on the rise. Hispanic and Black communities are affected more than others. For instance, studies show that if you have brown or black skin, controlling your blood glucose once you're diagnosed is more of a challenge. Black children with type 1 diabetes are also at higher risk of depression, diabetes complications, and hospital stays.

Structural racism plays a big part in explaining this inequality. Many long-standing laws and policies discriminate against people of color. So do systems such as health care.

You can be diagnosed with type 1 diabetes and live a long, healthy life. Keeping a close eye on your blood sugar levels will be key. Your doctor will give you a target range, and making healthy choices daily will help you stay within that range. It's also important to know the symptoms of very high or low blood sugar, and how to treat them.

Type 1 diabetes medications

You'll also need to use insulin every day.

When your doctor talks about insulin, they’ll mention three main things:

  • "Onset" is how long it takes to reach your bloodstream and begin lowering your blood sugar.
  • "Peak time" is when insulin is doing the most work in terms of lowering your blood sugar.
  • "Duration" is how long it keeps working after onset.

Several types of insulin are available.

  • Rapid-acting insulin starts to work in about 15 minutes. It peaks about 1 hour after you take it and continues to work for 2-4 hours.
  • Regular or short-acting insulin gets to work in about 30 minutes. It peaks between 2 and 3 hours and keeps working for 3-6 hours.
  • Intermediate-acting insulin won’t get into your bloodstream for 2-4 hours after your shot. It peaks within 4-12 hours and works for 12-18 hours.
  • Long-acting insulin takes several hours to get into your system and lasts about 24 hours.

Ways to take insulin

Insulin doesn't come in pill form, so you'll have to rely on other ways to get it into your body:

Insulin injections. Most insulin shots come in a small glass bottle called a vial. You draw it out with a syringe that has a needle on the end and give yourself the shot. Some kinds come in a prefilled pen.

Inhaled insulin. Your doctor may prescribe a rapid-acting insulin that you breathe into your mouth through a small device. It's not healthy to use this type if you smoke or have lung issues such as asthma.

Insulin pump. This device, which you wear, sends small bursts of insulin into your body throughout the day. It does this through a small tube just under your skin.

Your doctor will help you pick the type of insulin and delivery method that’s best for you.

Continuous glucose monitoring

Checking your blood sugar throughout the day will help make sure it stays within your target range. Pricking your finger and testing a blood sample with a blood glucose meter is one way to check. Many people also choose to wear a continuous glucose monitor (CGM).

Using a sensor just under your skin, this device can check your glucose every few minutes. Most models will alert you if it goes too high or too low, so you can treat it right away.

Other type 1 diabetes medications

Based on your health, your doctor could also prescribe:

  • Aspirin, to lower your risk of a heart event
  • Cholesterol-lowering drugs, to protect your heart
  • High blood pressure medication, to improve your kidney function

To feel your best, try to:

Get enough sleep. It can improve your blood sugar as well as your outlook. If you can, aim for at least 7 hours each night. Babies, kids, and teens will need even more.

Manage your stress. It's really common to feel angry or overwhelmed that you have type 1. Find healthy ways to reduce your stress. Talk to trusted friends and family members or ask your doctor to refer you to a counselor or therapist.

Quit smoking. Vaping and chewing tobacco are habits to stop, too. All these things narrow your blood vessels and put you at risk for other health issues. Talk to your doctor if you're not sure how to quit.

Visit your doctor regularly. Regular medical, dental, and eye exams can help you prevent issues, or treat them as soon as they're found.

Find ways to be active. Try to find a physical activity you enjoy. Even taking care of your garden counts. Talk to your doctor about how to balance your insulin dose and the food you eat with any activity you do.

Type 1 diabetes diet

Once you know how carbs, fats, and protein affect your blood sugar, you can build a healthy eating plan that helps keep your levels where they should be. Generally speaking, you'll focus on eating lots of nutrient-rich vegetables, fruits, and whole grains while cutting back on refined carbohydrates, such as white bread or pasta, which quickly raise your blood sugar.

No foods is off-limits, but you will need to limit some or enjoy smaller portions than you used to.

A diabetes educator or registered dietitian can help you learn to count carbohydrates at each meal and snack. If you're not sure how to connect with these experts, ask your doctor.

If your blood sugar isn't well-managed, it can lead to other health issues, including:

Diabetic ketoacidosis (DKA). If your body can't get enough glucose for fuel, it breaks down fat cells instead. This creates chemicals called ketones. Your liver releases the sugar it stores to help out. But your body can’t use it without insulin, so it builds up in your blood, along with the acidic ketones. This mix of extra glucose, dehydration, and acid buildup is known as ketoacidosis and can be life-threatening if not treated right away.

Heart disease. Diabetes can put you at higher risk of blood clots, high blood pressure, and cholesterol. These can lead to chest pain, heart attack, stroke, or heart failure.

Skin conditions. You're more likely to get blisters and rashes, as well as bacterial or fungal infections.

Gum disease. A dry mouth, increased plaque, and poor blood flow can all cause mouth issues.

Pregnancy complications. Type 1 diabetes raises your risk of early delivery, birth defects, stillbirth, and preeclampsia.

Retinopathy. This eye issue happens in about 80% of adults who have had type 1 diabetes for more than 15 years. To prevent it and to keep your eyesight , you'll need to control your blood sugar, blood pressure, cholesterol, and triglycerides.

Kidney damage. About 20%-30% of people with type 1 diabetes get a condition called nephropathy. The chance of getting it goes up over time. It’s most likely to show up 15-25 years after the onset of diabetes. It can lead to other serious problems such as kidney failure and heart disease.

Poor blood flow and nerve damage. Damaged nerves and hardened arteries lead to a loss of feeling in, and a lack of blood supply to, your feet. This raises your chances of injury and makes it harder for open sores and wounds to heal. When that happens, you could lose a limb. Nerve damage can also cause digestive problems such as nausea, vomiting, and diarrhea.

Exciting new treatments in the works include:

Glucose monitoring without needle sticks. This is proving to be a challenge for scientists.

Continuous ketone monitor (CKM). Like a CGM, a wearable device would monitor the fluid between your cells.

Longer-acting insulin. For instance, one type would keep your blood glucose steady for a week.

Immunotherapy. Some experts are looking for ways to "switch off" your immune system so it stops attacking the cells in your pancreas that make insulin.

"New" beta cells. One early-stage Australian study was able to get pancreatic stem cells to make insulin. If testing pans out, your remaining pancreas cells may be treated one day to start making insulin again.

Keep up with new research on type 1 diabetes through a trusted organization such as the CDC or the American Diabetes Association.

Type 1 diabetes is a lifelong condition. A diagnosis may feel overwhelming, but you can learn to manage your blood sugar. Making healthy choices every day will be key.