If I could change one thing about how type 1 diabetes is perceived by the public, it would be this: it is not caused by eating too much sugar, not caused by being overweight, and not a milder version of type 2 diabetes. It is a fundamentally different condition - an autoimmune disease in which the immune system destroys the insulin-producing beta cells of the pancreas - and conflating the two does real harm to people living with type 1.
I write this because I regularly see patients with type 1 diabetes who have been made to feel, by well-meaning but misinformed people around them, that their condition is somehow their fault. It is not. And because type 1 management has been transformed in the past decade by technology that many patients - particularly those from communities with less engagement with specialist diabetes services - may not know they are fully entitled to on the NHS.
What happens in type 1 diabetes - the physiology
Insulin is a hormone produced by the beta cells of the pancreatic islets of Langerhans. Its primary role is to act as a key that unlocks cells, allowing glucose from food to enter and be used for energy. Without insulin, glucose builds up in the bloodstream (hyperglycaemia) while cells are starved of energy despite abundant glucose being available. The body, sensing cellular starvation, begins breaking down fat for fuel - producing acidic byproducts called ketones.
When ketones accumulate rapidly, they cause diabetic ketoacidosis (DKA) - a potentially life-threatening emergency. DKA is the most common way type 1 diabetes first presents. Recognising the symptoms of DKA is potentially life-saving.
Symptoms of type 1 diabetes / early DKA: Extreme thirst and very frequent urination. Unexplained, rapid weight loss. Extreme fatigue. Blurred vision. Fruity or acetone-smelling breath. Nausea and vomiting. Abdominal pain. Confusion or reduced level of consciousness in severe DKA.
The classic presentation - particularly in children - involves a period of days to weeks of the first four symptoms, followed by rapid deterioration with vomiting and abdominal pain. In adults, the presentation can be more insidious.
Adult-onset type 1 (LADA - Latent Autoimmune Diabetes in Adults): Type 1 can develop at any age. Adults with type 1 are frequently misdiagnosed as type 2, particularly if they are overweight. LADA tends to progress more slowly than childhood-onset type 1. Key distinguishing features: relatively normal weight, failure to respond to oral medications, positive autoantibodies (GAD, IA-2). If you have been diagnosed with type 2 and tablets have not controlled your blood sugar despite good lifestyle adherence, ask your GP whether type 1 has been investigated.
Management in 2025 - what modern type 1 care involves
The management of type 1 diabetes has been transformed by technology in the past decade. For many patients - particularly those in specialist care - it now involves continuous glucose monitoring (CGM) and, increasingly, automated insulin delivery that dramatically reduces the burden of daily management.
Insulin regimens:
The standard regimen for most people with type 1 is basal-bolus - a long-acting background (basal) insulin once or twice daily to cover overnight and between-meal glucose levels, plus rapid-acting bolus insulin before each meal or snack, dosed based on carbohydrate content and current blood glucose.
Common basal insulins: insulin glargine (Lantus, Toujeo), insulin detemir (Levemir), insulin degludec (Tresiba - longest acting, most flexible timing).
Common rapid-acting insulin analogues: aspart (NovoRapid), lispro (Humalog), glulisine (Apidra). Faster rapid-acting options: faster aspart (Fiasp), lispro-aabc (Lyumjev) - better matched to meal timing for some people.
Continuous Glucose Monitoring (CGM):
CGM sensors worn on the arm or abdomen measure glucose in the interstitial fluid every 1-5 minutes, providing a continuous glucose reading with trend arrows (showing whether glucose is rising, stable, or falling) and alerts for high or low glucose.
The Freestyle Libre (Abbott) - a flash glucose monitoring system - is available on NHS prescription for all adults with type 1 diabetes. NICE recommends CGM for all adults with type 1 diabetes. If you have type 1 diabetes and are not currently using CGM, ask your diabetes team or GP why not and request a prescription. This is not an optional extra - it is a NICE-recommended standard of care.
Real-time CGM (rtCGM) systems like the Dexcom G7 and Libre 3 provide continuous glucose readings directly to a smartphone and can share readings with family members - valuable particularly for children and for people with hypoglycaemia unawareness.
Insulin pump therapy (CSII - Continuous Subcutaneous Insulin Infusion):
An insulin pump is a small device, worn on the body, that continuously delivers rapid-acting insulin through a cannula inserted under the skin. The user programmes basal rates for different times of day and delivers boluses via the pump for meals.
Pumps eliminate the need for separate basal insulin injections and allow much more precise basal rate adjustment. Available on NHS for people meeting NICE criteria (HbA1c above 69 despite multiple daily injections, or significant problematic hypoglycaemia).
Hybrid closed-loop (HCL) systems - the most advanced current technology:
Hybrid closed-loop systems combine CGM with an insulin pump and an algorithm that automatically adjusts insulin delivery based on CGM readings every few minutes. The system increases or decreases basal insulin delivery, and in some systems also delivers automatic correction boluses, to keep glucose in a target range with minimal user input.
Current NHS-available HCL systems include the Omnipod 5, MiniMed 780G, and CamAPS FX (used with compatible pumps). Clinical trial data shows dramatic improvements in time-in-range (the percentage of time glucose is between 3.9 and 10 mmol/L) and in HbA1c, with reductions in both hypoglycaemia and hyperglycaemia.
NICE has approved HCL systems for both adults and children with type 1 diabetes who are not achieving adequate glucose control with other means. Access is expanding. Ask your diabetes team specifically about HCL systems if you are not achieving good control.
Case study: Blessing's life transformation
Blessing, 26, was diagnosed with type 1 diabetes following a DKA admission at age 19. For five years after diagnosis, she managed on multiple daily injections and finger-prick testing. Her HbA1c fluctuated between 68 and 81 mmol/mol. She had stopped spontaneous exercise because she feared hypoglycaemia. She declined social invitations involving food because managing bolus insulin in public felt overwhelming.
At her annual review I discussed CGM. She started a Libre 3. Within weeks she described the experience of being able to see her glucose continuously as transformative - she could see the effect of different foods, the impact of exercise, the overnight pattern.
Six months later she was using an Omnipod 5 HCL system. Her last HbA1c was 52. Her time-in-range was 78%. She runs half marathons and does not find it significantly more complicated than running without diabetes.
"I thought diabetes meant a restricted life," she told me. "Nobody showed me what was actually possible."
Hypoglycaemia - recognising and treating low blood sugar
Hypoglycaemia (low blood glucose, below 4.0 mmol/L) is the main immediate risk of insulin therapy.
Symptoms: shakiness, sweating, palpitations, hunger, tingling around the mouth, pallor, irritability, confusion. Recognising the early symptoms and treating promptly prevents progression to severe hypoglycaemia.
Treatment: 15-20g fast-acting glucose. Glucose tablets, 150ml Lucozade original, 200ml pure fruit juice. Recheck after 15 minutes. If still below 4.0, repeat. Once above 4.0, have a longer-acting carbohydrate snack.
Severe hypoglycaemia (unconscious or unable to swallow): Glucagon injection (GlucaGen) or nasal glucagon powder (Baqsimi, available on NHS prescription). Someone else administers it. Call 999 if not recovering promptly.
People with type 1 diabetes should carry fast-acting glucose at all times.
Sources: NICE Clinical Guideline NG17 - Type 1 Diabetes in Adults (2015, updated 2022); DCCT Research Group, NEJM 1993 (landmark intensive management trial); Diabetes UK - Type 1 Diabetes Care Standards 2024; Bergenstal RM et al, NEJM 2021 (closed-loop systems trial); Winter WE et al, Journal of Clinical Endocrinology and Metabolism 2013 (LADA); NHS England - Diabetes Technology Programme.
