What complications may arise from type 1 diabetes?

by Ammy
(New Jersey )




QUESTION: I was recently diagnosed with type 1 diabetes and was told it may be hereditary. What complications can occur? If I keep my blood sugar controlled, will my risk become the same as someone without diabetes, and how does type 1 diabetes cause these problems?





Quick Answer


Type 1 diabetes can affect the eyes, kidneys, nerves, feet, heart, and blood vessels, but these complications are not inevitable. Keeping glucose near your individualized target, avoiding severe lows, controlling blood pressure and cholesterol, not smoking, and completing recommended screening can greatly reduce the risk. Your risk may not become identical to that of someone without diabetes, but modern insulin treatment, glucose monitoring, and preventive care can substantially improve long-term health.




Answer by Dr. Albana Greca, MD, MMedSc



Hi Ammy,



It is understandable to worry after a new diagnosis. Type 1 diabetes is an autoimmune disease: the immune system destroys the pancreatic beta cells that make insulin. Genes can increase susceptibility, but type 1 diabetes is not inherited in a simple or predictable way, and many people diagnosed with it have no close relative with the condition.



What Complications Can Occur?



Long-term complications are commonly grouped into two categories:




  • Small-vessel complications: diabetic retinopathy affecting the eyes, kidney disease, and peripheral or autonomic neuropathy affecting nerves.

  • Heart and circulation complications: coronary artery disease, heart attack, stroke, and peripheral artery disease.



Nerve damage and reduced circulation can also increase the risk of foot wounds, infection, and slow healing. You can review the broader picture in our guide to diabetes complications and prevention.



How Does High Glucose Cause Damage?



Complications are not caused simply by sugar “clotting” or completely blocking small arteries. Over time, excess glucose promotes glycation, oxidative stress, inflammation, and abnormal blood-vessel function. These changes can make retinal vessels leak or grow abnormally, damage the kidney filters, impair blood supply and function within nerves, and accelerate atherosclerosis in larger arteries.



Diabetic eye disease may cause no early symptoms, while diabetic kidney disease is often first detected through urine albumin and estimated kidney filtration tests. Neuropathy may cause numbness, tingling, burning pain, digestive problems, bladder symptoms, sexual dysfunction, or loss of warning symptoms during low glucose.



Does Good Control Remove the Risk?



Good glucose management can dramatically reduce the development and progression of eye, kidney, and nerve complications. However, no glucose target guarantees zero risk. Diabetes duration, glucose variability, severe hypoglycemia, blood pressure, cholesterol, smoking, kidney health, family history, and other factors also matter.



For many nonpregnant adults, a common HbA1c goal is below 7%, but your target should be individualized. Continuous glucose monitoring can also help increase time in range while reducing low glucose. Trying to achieve a very low HbA1c through frequent hypoglycemia is not safe.



Which Screening Tests Are Important?



For adults with type 1 diabetes, recommended preventive care generally includes:




  • HbA1c about every three months when treatment is changing or goals are not met, and at least twice yearly when control is stable.

  • A comprehensive dilated eye examination beginning about five years after diagnosis, then at intervals based on the findings.

  • Annual kidney screening with urine albumin-to-creatinine ratio and eGFR beginning after five years of type 1 diabetes.

  • Annual neuropathy and foot assessment beginning after five years, with earlier evaluation if symptoms occur.

  • Regular blood pressure, cholesterol, smoking, weight, dental, and cardiovascular-risk review.

  • Thyroid screening soon after diagnosis and later when clinically indicated; celiac testing when symptoms or other findings suggest it.



Report new blurred vision, numbness, burning pain, foot wounds, swelling, changes in urination, dizziness on standing, digestive symptoms, or sexual and bladder problems rather than waiting for a routine visit. Our guide to diabetic neuropathy symptoms explains early warning signs.



Acute Complications Also Matter



Type 1 diabetes can cause diabetic ketoacidosis when the body does not receive enough insulin. Insulin treatment can also cause hypoglycemia. Learn your sick-day rules, when to test ketones, how to treat glucose below 70 mg/dL, and how family members should use glucagon. Never stop basal insulin during illness unless your diabetes clinician gives specific instructions.




Important Safety Note


Seek emergency care for repeated vomiting, abdominal pain, rapid or difficult breathing, fruity-smelling breath, confusion, severe dehydration, high ketones, seizure, unconsciousness, or severe hypoglycemia that requires another person’s help. Do not omit insulin because you are unable to eat without following your sick-day plan.





Doctor’s Note


A diagnosis of type 1 diabetes does not mean complications are unavoidable. The strongest protection comes from consistent insulin use, glucose monitoring, preventing severe highs and lows, and managing blood pressure, cholesterol, smoking, exercise, nutrition, and screening together. Ask your diabetes team for a written annual-care checklist and individualized targets.





Educational safety note: This answer is for general diabetes education only. It does not replace personal medical advice, diagnosis, or treatment. Do not start, stop, or change insulin, other medicines, supplements, diet, or exercise plans without speaking with your healthcare provider.




Related Questions




Related Resources




Last reviewed: July 2026.




Click here to post comments or follow up

Ask the Doctor now? Simply click here to return to Side effects of Diabetes.