Diabetes

What is diabetes?

Diabetes is a group of conditions in which blood glucose is persistently high, either because the pancreas produces too little insulin or because the body resists its effect. Type 2 accounts for the large majority of cases. The long term concern is damage to blood vessels and nerves, so treatment targets blood pressure and cholesterol alongside glucose.

Causes

• Insulin resistance with progressive beta cell decline in type 2
• Autoimmune destruction of insulin producing cells in type 1
• Genetic predisposition
• Excess visceral fat
• Certain medicines such as long term corticosteroids

Symptoms

• Increased thirst and frequent urination
• Fatigue
• Unintended weight loss, more typical of type 1
• Blurred vision
• Slow healing wounds
• Recurrent skin or genital infections
• Tingling or numbness in the feet

Risk factors

• Overweight or obesity, particularly central adiposity
• Physical inactivity
• Family history of diabetes
• Age over 40
• South Asian, African or Caribbean ancestry
• Previous gestational diabetes or polycystic ovary syndrome

Diagnosis

• HbA1c of 48 mmol per mol or 6.5 percent or above
• Fasting plasma glucose of 7.0 mmol per litre or above
• Oral glucose tolerance test where needed
• Repeat testing to confirm in people without symptoms
• Antibody and C peptide testing when type 1 is suspected

Treatment

• Structured education, dietary change and regular activity
• Metformin as usual first line medicine in type 2
• SGLT2 inhibitors and GLP 1 receptor agonists, especially with heart or kidney disease
• Insulin when required, and always in type 1
• Blood pressure and lipid management
• Annual eye, foot and kidney screening

Self care

• Take medicines as prescribed and attend annual reviews
• Check feet daily for cuts, blisters and colour change
• Stay active most days, combining aerobic and resistance exercise
• Focus on portion size and reducing refined carbohydrates
• Attend eye screening every year without fail
• Do not smoke, which multiplies vascular risk
• Know how to manage illness days if you use insulin

When to see a doctor

Book an appointment if:

• Glucose readings consistently outside target
• New numbness, tingling or burning in the feet
• Any foot wound, blister or colour change
• Blurred vision or floaters
• Unexplained weight loss
• Recurrent infections or slow healing

Some symptoms need emergency care rather than an appointment. See the warning signs listed above.

Prevention

• Type 2 diabetes is often preventable through weight management and activity
• Around 150 minutes of moderate activity weekly
• Reduce sugary drinks and refined carbohydrates
• Attend screening if you have risk factors or previous gestational diabetes
• Stop smoking
• Structured prevention programmes substantially reduce progression from prediabetes

Outlook

With good glucose, blood pressure and cholesterol control, most people with diabetes avoid serious complications and live a normal lifespan. Type 2 can go into remission with substantial weight loss, particularly within a few years of diagnosis. Complications are largely preventable, and annual eye, foot and kidney screening exists to catch them while still treatable.

Related conditions

Common questions