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 cells of the pancreas — and conflating the two does a significant disservice to people living with it.
I write this because I regularly see patients with type 1 diabetes who have been made to feel, by well-meaning but uninformed people, 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 in lower-income communities or those who came to the UK from other countries — may not know they are entitled to.
What happens in type 1 diabetes
Insulin is a hormone that acts as a key — it allows glucose from food to enter cells and be used for energy. Without insulin, glucose builds up in the bloodstream (hyperglycaemia) while cells are starved of energy. The body then starts breaking down fat for fuel, producing acidic byproducts called ketones.
When ketones accumulate rapidly, they can cause diabetic ketoacidosis (DKA) — a medical emergency that is often how type 1 diabetes is first diagnosed.
Symptoms at diagnosis (usually appearing over days to weeks):
- Extreme thirst (polydipsia)
- Frequent urination (polyuria)
- Unexplained weight loss
- Extreme fatigue
- Blurred vision
- Fruity-smelling breath (ketones)
- Nausea and vomiting (DKA)
Type 1 diabetes can develop at any age — it is not only a childhood condition. Adult-onset type 1 (sometimes called LADA — Latent Autoimmune Diabetes in Adults) is frequently misdiagnosed as type 2. If you have been diagnosed with type 2 but tablets are not controlling your blood sugar despite good lifestyle adherence, ask your doctor whether type 1 or LADA has been excluded.
Who gets type 1 diabetes
The cause involves a combination of genetic predisposition and an environmental trigger (possibly a viral infection) that causes the immune system to attack the pancreas. Specific HLA gene variants increase susceptibility.
Type 1 diabetes is less common in people of African ancestry than in white populations — the incidence in sub-Saharan Africa is significantly lower than in Scandinavia, for example, where rates are among the highest in the world. However, Africans in the diaspora do develop type 1 diabetes, and a specific subtype called ketosis-prone diabetes (sometimes called Flatbush diabetes) is more common in people of African and Caribbean origin. This subtype can present like type 1 with DKA but may later become manageable without insulin — it requires specialist assessment and ongoing careful monitoring.
Management — what modern type 1 care involves
Type 1 diabetes management has been revolutionised in the past 10 years. The goal is to keep blood glucose in a target range as consistently as possible, minimising both hypoglycaemia (low blood sugar) and hyperglycaemia (high blood sugar), while maintaining quality of life.
Insulin regimens
Multiple daily injections (MDI): The standard approach — a long-acting basal insulin once or twice daily (e.g. Lantus, Levemir, Tresiba) plus rapid-acting bolus insulin before meals (e.g. NovoRapid, Humalog, Fiasp). Doses are adjusted based on carbohydrate intake, activity, and blood glucose readings.
Insulin pump therapy (CSII): A small device worn on the body continuously delivers a baseline rate of rapid-acting insulin, with bolus doses given at meals. More flexible than injections for many people. Available on the NHS for people who meet criteria.
Continuous Glucose Monitoring (CGM)
This is the technology that has most transformed type 1 diabetes management. A small sensor worn on the arm or abdomen measures glucose in interstitial fluid every few minutes and transmits readings to a phone or reader. No finger pricks required (or far fewer).
Libre (Abbott): Widely available on NHS prescription for people with type 1 diabetes. Gives glucose readings every minute, trend arrows showing direction and speed of change, and alerts for high or low values.
Dexcom G7: More advanced CGM with better accuracy and predictive alerts.
CGM dramatically improves time-in-range (the percentage of time blood glucose is within target), reduces hypoglycaemia, and reduces HbA1c.
If you have type 1 diabetes and are not on CGM — ask your diabetes team or GP why not. NICE recommends CGM for all adults with type 1 diabetes. It is an NHS entitlement.
Hybrid closed-loop systems ("artificial pancreas")
The most advanced current technology combines a CGM with an insulin pump that automatically adjusts insulin delivery based on glucose readings. Systems like the Omnipod 5, CamAPS FX, and MiniMed 780G do much of the manual decision-making automatically. Studies show significant improvements in time-in-range and HbA1c.
These systems are increasingly available on the NHS and represent a genuine step toward the "artificial pancreas" — automated insulin delivery that removes much of the cognitive burden of managing type 1 diabetes.
Case study: Blessing navigates a new diagnosis
Blessing, 26, came to the emergency department of a London hospital with nausea, abdominal pain, confusion, and fruity-smelling breath. Her blood glucose was 32 mmol/L (normal fasting: 4–7). Her blood gases showed DKA. She was admitted, started on IV insulin and fluids, and recovered over 48 hours.
She had been losing weight for three weeks and increasingly thirsty. Her family had assumed she was working too hard. She had not seen a GP.
After her DKA was treated, she was referred to the diabetes team, started on basal-bolus insulin, and given a Libre sensor. She was referred to a diabetes structured education programme (DAFNE — Dose Adjustment For Normal Eating) to learn carbohydrate counting and insulin adjustment.
Two years later her HbA1c is 52 — well-controlled. She wears a Libre 3 sensor and adjusts her insulin confidently. She runs half marathons (with careful glucose management around exercise). She says the first year was overwhelming but that having the right technology and education made the difference.
"Nobody told me I could do any of this," she said. "I thought diabetes meant a restricted life. It doesn't have to."
Hypoglycaemia — the immediate risk
Low blood sugar (hypoglycaemia — "hypo") occurs when there is too much insulin relative to glucose available. It can happen after too large an insulin dose, unexpected exercise, alcohol without food, or missed meals.
Symptoms: Shakiness, sweating, palpitations, hunger, pallor, confusion, aggression in some people.
Treatment: 15–20g fast-acting glucose — glucose tablets, Lucozade, fruit juice, jelly beans. Followed by a longer-acting carbohydrate. Recheck glucose after 15 minutes.
Severe hypo (unconscious or unable to swallow): Glucagon injection or nasal glucagon spray (Baqsimi — available on prescription and should be carried by people with type 1 and given to family members). Call 999.
People with type 1 diabetes should carry fast-acting glucose at all times.
Long-term complications — and how to reduce risk
Sustained high blood glucose causes damage to blood vessels and nerves over time. Complications include:
- Retinopathy (eye damage — leading cause of blindness in working-age adults)
- Nephropathy (kidney damage)
- Neuropathy (nerve damage — pain, numbness in feet)
- Cardiovascular disease
These complications are not inevitable. The DCCT trial demonstrated definitively that tight blood glucose control dramatically reduces the risk of all microvascular complications. Modern technology — CGM, pumps, better insulins — makes tight control significantly more achievable than it was 20 years ago.
Annual checks (all should be offered on the NHS): eye screening, urine albumin (kidney), foot examination, HbA1c, cholesterol, blood pressure.
Sources: NICE Clinical Guideline NG17 — Type 1 Diabetes in Adults (2015, updated 2022); DCCT Research Group, NEJM 1993; Diabetes UK — Type 1 Diabetes Care (2024); Winter WE et al, Journal of Clinical Endocrinology & Metabolism 2013 (ketosis-prone diabetes); CamAPS FX trial data 2022.