what is type 1 diabetes

Type 1 diabetes is a chronic autoimmune condition where the body's immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas.¹²

Without these cells, the body can no longer produce insulin—the hormone required to move glucose (sugar) from the bloodstream into cells to be used for energy. This causes sugar to build up in the blood, leading to high blood sugar (hyperglycemia).¹²³⁴

Key Facts

• Not Preventable: Type 1 diabetes cannot be prevented, and it is not caused by eating too much sugar.¹²
• Lifelong Treatment: Because the body makes little to no insulin, people with type 1 diabetes must take insulin every day—either through injections or an insulin pump—to survive and manage their blood glucose levels.¹²
• Onset: It is often diagnosed in children, teens, and young adults, though it can develop at any age.¹
• Common Symptoms: Symptoms often appear quickly and include excessive thirst, frequent urination (especially at night), extreme tiredness, blurred vision, and unexplained weight loss.¹²³
• Risks & Complications: If left untreated or poorly managed, it can lead to severe complications such as diabetic ketoacidosis (DKA), nerve damage, kidney disease, and heart problems.¹²

You can learn more about daily care and guidance through the NHS Type 1 Diabetes Guide or find support resources via Breakthrough T1D UK.¹²If you are looking for specific information, let me know:

• Are you asking for yourself, a child, or someone else?
• Would you like to know more about early warning signs, daily management (like insulin or monitoring), or support resources?

Type 1 diabetes is a lifelong autoimmune condition where the body cannot produce insulin . Without insulin, glucose (sugar) builds up in the bloodstream instead of entering cells to be used for energy.¹²³⁴

While it often develops in children and young adults, it can appear at any age. It accounts for roughly 5% to 10% of all diabetes cases and is not caused by diet or lifestyle.¹²³

How It Works

• Immune system attack. The body's immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas.¹²
• Insulin deficiency. Insulin acts like a key that unlocks cells so glucose can enter. Because the pancreas makes little to no insulin, this process stops.¹²
• High blood sugar. Glucose stays in the blood, causing high blood glucose levels (hyperglycaemia) while starving the body's cells of energy.¹²³

Common Symptoms

Symptoms often develop quickly over a few days or weeks, especially in younger people. According to the NHS, key signs include:¹

• Increased thirst. Feeling very thirsty all the time.
• Frequent urination. Needing to pass urine more often than usual, particularly at night.
• Extreme tiredness. Feeling unusually fatigued or lacking energy.
• Unexplained weight loss. Losing weight and muscle bulk rapidly without trying.¹²

Causes and Risk Factors

• Unknown triggers. Scientists do not know the exact cause, though a viral infection or environmental factor may trigger the immune response in people who are already susceptible.
• Genetics. Having a parent or sibling with the condition slightly increases your risk.
• Not preventable. Unlike type 2 diabetes, there is currently no way to prevent type 1 diabetes.¹²³⁴⁵⁶

Management and Treatment

There is currently no cure, so people with type 1 diabetes must manage their blood sugar levels every day. Guidance from Diabetes UK highlights the core parts of daily care:¹

• Daily insulin. People must take insulin every day via injections or an insulin pump, as stomach acid would destroy insulin if taken as a pill.
• Glucose monitoring. Blood sugar levels are tracked regularly using a finger-prick meter or a wearable continuous glucose monitor (CGM).
• Carbohydrate counting. Tracking carbohydrate intake helps calculate the right insulin dose to keep blood sugar in a safe target range.
• Managing lows and highs. Untreated high blood sugar can lead to a life-threatening emergency called diabetic ketoacidosis (DKA), while too much insulin can cause dangerously low blood sugar (hypoglycaemia).¹²³⁴⁵

Would you like to explore how type 1 differs from type 2 diabetes, or learn more about modern insulin pumps and glucose monitors?

Type 1 diabetes is a lifelong condition in which the body's immune system mistakenly attacks and destroys the cells in the pancreas that produce insulin.

Insulin is a hormone that helps move sugar (glucose) from your blood into your body's cells, where it is used for energy.

When someone has type 1 diabetes, their body produces little or no insulin, meaning glucose builds up in the bloodstream.

What causes type 1 diabetes?

• It is an autoimmune condition – the immune system attacks the insulin-producing cells.
• It is not caused by eating too much sugar or having an unhealthy lifestyle.
• It can develop at any age, although it is commonly diagnosed in children and young adults.
• Genetics and environmental factors may play a role.

Common symptoms

Feeling extremely thirsty

Drinking much more water than usual.

Peeing frequently

Including waking up during the night.

Extreme tiredness

Feeling exhausted even after sleeping.

Unexplained weight loss

Losing weight without trying.

Blurred vision

Changes in eyesight.

Symptoms can develop quite quickly, sometimes over days or weeks.

How is type 1 diabetes treated?

There is currently no cure, but it can be managed with treatment.

People with type 1 diabetes need to:

1. Take insulin every day – through injections or an insulin pump.
2. Monitor blood sugar levels – often using a continuous glucose monitor (CGM).
3. Balance food and insulin – particularly understanding carbohydrates.
4. Stay physically active – while monitoring blood sugar around exercise.
5. Attend regular diabetes check-ups.

What happens if it isn't treated?

Without enough insulin, the body can develop a dangerous condition called diabetic ketoacidosis (DKA).

Symptoms include:

• Vomiting and stomach pain.
• Feeling very thirsty.
• Deep or rapid breathing.
• Fruity-smelling breath.
• Drowsiness or confusion.

DKA is a medical emergency and requires immediate hospital treatment.

Type 1 vs Type 2 diabetes

The important thing to remember: Type 1 diabetes is not the person's fault. With the right treatment and support, people with type 1 diabetes can live long, healthy and active lives.

Are you asking because you or someone you know has recently been diagnosed with type 1 diabetes, or are you just wanting to understand the condition better?