What is type 1 diabetes (T1D)?

Facts about T1D and what’s happening in the body

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What Is T1D?T1D in the Body Stages of T1D Find a T1D Specialist T1D Complications

Understanding the basics of T1D

T1D is a lifelong, progressive, autoimmune disease in which the body can no longer make enough insulin to regulate blood sugar and daily insulin injections are needed. If not properly managed, insulin-dependent (Stage 3) T1D can lead to complications that may require emergency hospitalization.

A common misconception is that T1D affects mostly children, but anyone at any age can develop T1D. In fact, ~60% of new T1D diagnoses occur after the age of 20

A family history of T1D and certain autoimmune diseases (Hashimoto's, Graves', or celiac disease) are 2 important risk factors for developing T1D

T1D progresses in stages and has no visible signs or symptoms in its early stages; you may not even know it’s happening

Compared to adults with Stage 1, children with Stage 1 progress more rapidly to Stage 3, which makes early screening and close monitoring especially important to give families an opportunity to act before symptoms appear and the disease advances

T1D vs T2D: The differences matter

Did you know that over 40% of adults with T1D over age 30 were initially diagnosed as having T2D?
Abnormal blood sugar is a symptom that appears in both T1D and T2D, but they have important differences. Knowing which is which can help ensure the right diagnosis and treatment plan.

Key facts about T1D

An autoimmune disease that is not preventable
Less common than T2D, but diagnoses are increasing
The body can’t make enough insulin on its own
Cannot be prevented or corrected by diet, exercise, or any known treatment
Cannot be diagnosed by blood glucose tests alone

Key facts about T2D

A metabolic disease that may be preventable
The most common type of diabetes
The body is unable to use insulin properly
Risk for T2D can be lowered by lifestyle changes like diet and exercise
Typically diagnosed by blood glucose tests

What happens in your body when you have T1D

Insulin is essential for converting food to energy in the body and for regulating blood sugar. It is made and released into the body by special cells in the pancreas called beta cells. But in T1D, the immune system mistakenly attacks beta cells, reducing your body’s natural ability to produce insulin. Over time, the body can no longer produce insulin on its own.

Without insulin, blood sugar levels become too high, causing symptoms as well as potentially serious complications.

~60% of people do not know they have T1D until they are diagnosed in an emergency that requires hospitalization.

Autoantibodies are the key to spotting T1D early

T1D autoantibodies are signals that show up in the blood when the immune system attacks insulin-producing beta cells. Testing positive for multiple autoantibodies may indicate that T1D is already progressing in the body even if symptoms are not present. But through autoantibody (AAb) screening and blood sugar testing, it's possible to detect T1D early, before symptoms appear and it becomes an emergency.

AAb screening is a blood test that is not included in annual blood work. If you have an increased risk for T1D, screening is a proactive first step that can reduce your risk of sudden complications at T1D diagnosis and potentially open the door to treatment.

T1D progresses in stages

In progressive diseases like T1D, stages indicate how far a condition has advanced. Knowing which stage you or your loved one is in can help guide next steps.

Insulin is not needed
The immune system has started attacking beta cells
No obvious symptoms
Blood sugar is still normal
2 or more T1D-related autoantibodies are present

Daily insulin is not needed
Beta cells continue to be attacked
Still no obvious symptoms
Blood sugar is abnormal
2 or more T1D-related autoantibodies are present

*Treatment with TZIELD may be possible for eligible patients

Daily Insulin injections are needed and obvious symptoms are present
Many beta cells are damaged and can’t make enough insulin to regulate blood sugar
High blood sugar (hyperglycemia)
1 or more T1D-related autoantibodies may be present

Dependence on daily insulin injections to control blood sugar
Few or no working beta cells for body to produce insulin on its own
Long-term health complications are common
T1D-related autoantibodies may no longer be present

Find a T1D specialist near you

T1D specialists are also called endocrinologists. They can diagnose, treat, and manage type 1 diabetes for you or your loved one.

Start Your Search

The search tool and results are provided independently by Healthgrades™. Sanofi does not endorse or recommend any particular physician and search results may not include a comprehensive list of doctors in your area. Sanofi is not responsible for any Healthgrades content.

A complication of T1D:
diabetic ketoacidosis (DKA)

DKA is a potential medical emergency where the blood becomes acidic as a result of not having enough insulin in the body. DKA can happen without warning and, if not addressed in time, can lead to complications that could require hospitalization.

It’s important to know the signs of DKA:

Thirst or a very dry mouth

Frequent urination

Constantly feeling tired

Dry or flushed skin

Difficulty breathing

Fruity odor on breath

A hard time paying attention, or confusion

Nausea, vomiting, or abdominal pain^†

Contact your doctor right away if you have any of these symptoms and suspect you may have T1D

There are no data to suggest that TZIELD will have any effect on these outcomes.

*Vomiting can be caused by many illnesses, not just diabetic ketoacidosis. If vomiting continues for more than 2 hours, contact your healthcare provider.

T1D is often diagnosed in Stage 3 during a DKA event resulting in emergency hospitalization

Screen for T1D autoantibodies

An opportunity to reshape the journey with T1D—and it starts with screening.

Learn about screening

TZIELD is a treatment for Stage 2 T1D

Managing T1D is no longer just about waiting for symptoms to appear. The Patient Brochure is a helpful resource for learning more about T1D and how TZIELD can help delay the onset of insulin-dependent (Stage 3) T1D in patients 1 year of age and older with Stage 2 T1D.

Download the Patient Brochure

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Important Safety Information and Indication

What is the most important information I should know about TZIELD? TZIELD may cause serious side effects. These including:

Viral Reactivation. Epstein-Barr virus (EBV) and cytomegalovirus (CMV) are common viruses that may stay inactive in your body after an initial infection. TZIELD may cause these viruses to become active again which, especially in patients with a weakened immune system, can become serious and potentially life-threatening. These viral reactivations can happen during treatment with TZIELD and up to 2 months after your last dose. Your healthcare provider will test you for active EBV and CMV infections before treatment with TZIELD. Contact your healthcare provider right away if you develop symptoms of an infection during or after treatment with TZIELD (such as fever, swollen glands, or fatigue).
Cytokine release syndrome (CRS). Signs and symptoms may start during the first 5 days of TZIELD treatment and could include fever, nausea (with or without vomiting), feeling tired (fatigue), headache, muscle and joint pain, or increased liver enzymes in your blood. Tell your healthcare provider right away if you develop any signs and symptoms of CRS during treatment with TZIELD.
Decrease in white blood cells. TZIELD may cause a decrease in a type of white blood cell called lymphocytes. A decrease in white blood cells is a serious, but common side effect that can affect your body’s ability to fight infections. A decrease in white blood cell counts can happen after your first dose. Your white blood cell counts will start to go back to normal after your fifth dose of TZIELD. Some people may develop longer and more severe decreases in lymphocytes.

Your healthcare provider will do blood tests to check for active infections, verify your liver function and your complete blood counts before you start treatment and during treatment with TZIELD. During and after your treatment with TZIELD, your healthcare provider will check for serious side effects, as well as other side effects, and treat you as needed. Your healthcare provider may temporarily or completely stop your treatment with TZIELD, if you develop liver problems, have a serious infection or viral reactivation, or if your blood counts stay too low.

What should I tell my healthcare provider before receiving TZIELD? Before or after receiving TZIELD, tell your healthcare provider about all your medical conditions, including if you:

have any of the conditions or symptoms listed in the section “What is the most important information I should know about TZIELD?”
have a weakened immune system, including if you have Down syndrome.
have a serious infection or an infection that does not go away or keeps coming back (chronic).
have recently received or are scheduled to receive an immunization (vaccine). TZIELD may affect how well a vaccine works. Tell your healthcare provider that you are receiving treatment with TZIELD before receiving a vaccine.
are pregnant or plan to become pregnant. TZIELD may harm your unborn baby. Do not receive TZIELD during pregnancy and at least 30 days before a planned pregnancy.

If you become pregnant while taking TZIELD, you are encouraged to report your pregnancy to us at our Adverse Event reporting line at 1-800-633-1610 or visit https://ae.reporting.sanofi.

are breastfeeding or plan to breastfeed. It is not known if TZIELD passes into your breast milk and if it can harm your baby. Talk to your healthcare provider about the best way to feed your baby if you receive TZIELD.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

What are the possible side effects of TZIELD? The most common side effects of TZIELD include:

decrease in white blood cell counts
vomiting
rash
diarrhea
headache

These are not all of the possible side effects of TZIELD. For more information, ask your healthcare provider or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects to us at 1-800-633-1610 or www.fda.gov/medwatch or 1-800-FDA-1088.

Please see full Prescribing Information, including Risk of SERIOUS SIDE EFFECTS and Medication Guide.

What is TZIELD?

TZIELD is a prescription medicine used to delay the onset of Stage 3 type 1 diabetes, which is when your body cannot make enough insulin on its own and may require insulin injections. TZIELD is for adults and children 1 year of age and older who have Stage 2 type 1 diabetes. This means that they have tested positive for 2 or more type 1 diabetes-related autoantibodies, have abnormal blood sugar levels, and do not have type 2 diabetes or other forms of diabetes.

It is not known if TZIELD is safe and effective in children under 1 years of age.