Anatomy
The pancreas is a long, flat gland located behind the stomach. It contains clusters of cells called islets of Langerhans that produce insulin and glucagon.
Organ Health · Diabetes & Blood Sugar
Diabetes & Blood Sugar
Understand how your body regulates blood sugar, what HbA1c and glucose tests measure, and how lifestyle influences long-term metabolic health.
Educational information only. Detectives Health helps explain laboratory tests and organ health in plain English. It does not diagnose disease, prescribe treatment or replace professional medical advice. Please discuss your individual results with a qualified healthcare professional.
Understanding the organ
Anatomy, function and importance
Function
Insulin lowers blood sugar by helping cells absorb glucose for energy. Glucagon raises blood sugar when it drops too low. Together they keep glucose within a narrow, healthy range.
Why it matters
Stable blood sugar supports energy, brain function, mood, weight, cardiovascular health and long-term wellbeing of the eyes, nerves and kidneys.
How it works
A simple explanation in plain English
After eating, carbohydrates are broken down into glucose, which enters the bloodstream.
The pancreas responds by releasing insulin, which acts like a key that allows glucose to enter cells for energy.
Between meals, the pancreas releases glucagon to help the liver release stored glucose and prevent blood sugar dropping too low.
Over years, persistently high blood sugar may damage small blood vessels and increase long-term health risks.
Laboratory tests
Which laboratory tests assess this organ
Each test contributes a small piece of information. Results are always interpreted alongside symptoms, medical history and other investigations.
HbA1c (Glycated Haemoglobin)
- What it measures
- Average blood sugar levels over the previous 2–3 months, expressed as mmol/mol or %.
- Why it is requested
- Used to screen for and monitor diabetes and prediabetes.
- Factors influencing results
- Anaemia, certain haemoglobin variants, recent blood loss and pregnancy may affect HbA1c interpretation.
Fasting Glucose
- What it measures
- The level of glucose in the blood after fasting for at least 8 hours.
- Why it is requested
- Used in the diagnosis of diabetes and prediabetes.
Random Glucose
- What it measures
- The glucose level at any point in the day, regardless of when you last ate.
- Why it is requested
- May be used when symptoms of high blood sugar are present.
Insulin
- What it measures
- The level of insulin the pancreas is producing.
- Why it is requested
- Sometimes used to assess insulin resistance or specific conditions.
C-Peptide
- What it measures
- A protein released alongside insulin, used to assess how much insulin the pancreas is making.
- Why it is requested
- Occasionally requested to help distinguish types of diabetes.
Factors that influence results
Why results vary between people and over time
Laboratory values are shaped by many day-to-day factors. Understanding them helps you and your healthcare professional interpret results in context.
Age
The risk of type 2 diabetes increases with age but healthy habits reduce risk at any stage.
Weight
Excess weight, particularly around the abdomen, is a leading modifiable risk factor.
Diet
Diets high in refined sugar and ultra-processed foods can raise long-term glucose levels.
Physical activity
Regular movement improves how effectively the body uses insulin.
Sleep
Poor or short sleep is linked with impaired glucose tolerance.
Stress
Chronic stress can raise stress hormones that influence blood sugar.
Medication
Some medications, including certain steroids, may raise blood glucose levels.
Family history
A family history of diabetes may increase individual risk.
Preparing for your blood test
Practical educational guidance
Preparation varies between laboratory tests. Always follow the specific instructions from the clinician or laboratory that requested your sample.
- Follow any fasting instructions given by the requesting clinician — some tests such as fasting glucose or a lipid profile need 8–12 hours without food.
- Take regular medication as usual unless your healthcare professional advises otherwise.
- Mention any supplements — biotin, high-dose vitamins and herbal remedies can influence several laboratory tests.
- Stay well hydrated with water in the hours before your test; dehydration can affect several markers.
- Avoid unusually strenuous exercise in the 24 hours before testing, as this may temporarily alter some results.
- Where possible, attend at a consistent time of day — several hormones and enzymes follow daily rhythms.
- Postpone routine testing if you have an acute infection, unless your clinician specifically wants a result during illness.
Healthy lifestyle
Everyday habits that support this organ
Consistent healthy habits may support organ function over time. They do not replace medical assessment when concerns arise.
Balanced meals
Combining protein, fibre and healthy fats with carbohydrates helps steady blood sugar rises.
Choose whole grains
Whole grains raise blood sugar more slowly than refined grains.
Increase vegetables
Vegetables provide fibre and micronutrients with a low glucose impact.
Limit sugary drinks
Sugary drinks cause rapid glucose spikes and are strongly linked with weight gain.
Move daily
Regular walking, cycling, swimming or strength work improves insulin sensitivity.
Maintain a healthy weight
Even modest weight loss can significantly improve blood sugar control.
Prioritise sleep
Consistent, good-quality sleep supports metabolic and hormonal balance.
Reduce alcohol
Following low-risk drinking guidance helps blood sugar and liver health.
Symptoms to discuss
Changes worth mentioning to a healthcare professional
These symptoms do not confirm any diagnosis. They are educational prompts for a professional assessment when they are new, persistent or worsening.
- • Persistent thirst
- • Passing urine more often, especially at night
- • Unexplained tiredness
- • Blurred vision
- • Unexplained weight loss
- • Slow-healing wounds
- • Recurring infections such as thrush
- • Numbness or tingling in the feet
Seek urgent medical assessment
In the UK call 999 for emergencies, or 111 for urgent advice. If you experience any of the following, seek help without delay:
- • Severe drowsiness or confusion
- • Deep, rapid breathing with fruity-smelling breath
- • Persistent vomiting with high or low blood sugar
- • Loss of consciousness or seizures
Routine monitoring
Health checks and screening in an educational context
Recommendations vary between individuals. Your healthcare professional will advise which tests apply to you and how often.
- Include HbA1c in routine health checks if you have risk factors
- Attend annual diabetes reviews if you have prediabetes or diabetes
- Monitor blood pressure and cholesterol alongside blood sugar
- Discuss weight, diet and activity at regular reviews
- Attend recommended eye, foot and kidney checks if you have diabetes
- Discuss family history of diabetes with your GP
Questions you may wish to discuss
Prompts for your next healthcare appointment
These are educational conversation starters — not a script. Bring the ones that feel most relevant to your situation.
- What does this result mean in my individual situation?
- Should the test be repeated, and if so when?
- Are further investigations recommended based on this result?
- Could any of my medications or supplements be influencing the result?
- Are lifestyle changes likely to help, and which ones would you prioritise?
- How does this result fit with my symptoms and medical history?
- What would prompt a change of plan or a specialist referral?
Frequently asked questions
Common educational questions
Q.What is prediabetes?
Prediabetes describes blood sugar levels that are higher than normal but not high enough to be classed as diabetes. It is an important early opportunity to reduce risk through lifestyle.
Q.Can diabetes be reversed?
Type 2 diabetes may be improved or, in some cases, put into remission with sustained weight, dietary and lifestyle changes. Your healthcare professional can advise on your options.
Q.Is fruit safe to eat?
Whole fruit provides fibre, vitamins and antioxidants and is part of a balanced diet. Fruit juices and dried fruit are more concentrated in sugar.
Q.Do I need to fast for HbA1c?
No. HbA1c reflects average glucose over months and does not require fasting.
Biomedical Scientist's insight
The science behind your result
Biomedical Scientists perform, validate and quality-check laboratory analyses before results are authorised for release. Every test is run against calibrated standards and internal controls, and reviewed for analytical accuracy. Laboratory findings are then interpreted by healthcare professionals alongside your symptoms, examination findings and medical history — which is why context matters as much as the number on the report.
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Scientific leadership
Steve Diongo
Founder & Scientific Lead · HCPC-Registered Specialist Biomedical Scientist · 15+ years NHS · 20+ years laboratory medicine
This module has been developed and reviewed by the Detectives Health Professional Team under the scientific leadership of Steve Diongo. Educational content is regularly updated using recognised laboratory standards, current scientific evidence and professional best practice.
Reviewed against NHS, NICE, CDC, WHO and USPSTF guidance.
Educational information only. Detectives Health does not diagnose disease, prescribe treatment or replace professional medical advice.
Please discuss your individual laboratory results, symptoms and health concerns with a qualified healthcare professional.