How Do You Know If You Have Diabetes? 8 Symptoms to Look Out For
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The early symptoms of diabetes can be surprisingly easy to dismiss. Feeling more tired than usual, being thirstier, or needing the toilet more often are the kinds of things many of us put down to a busy life, getting older, or simply not sleeping well. As a result, a lot of people live with symptoms for weeks, months or even years before seeking advice.
Recognising the warning signs matters, because the earlier diabetes is identified, the sooner it can be managed and the lower the risk of complications. This is a clear, clinician-informed guide to the most common symptoms of diabetes, how type 1 and type 2 differ, why symptoms happen, and what to do if you are concerned.
Importantly, experiencing one of these symptoms on its own rarely means you have diabetes. But if symptoms are persistent, or several appear together, it is worth getting checked.
8 common symptoms of diabetes
Diabetes symptoms can affect the whole body, and they are broadly similar whether you have type 1 or type 2. The most common warning signs to be aware of are: [1][2]
● Feeling very thirsty that does not go away, even after drinking.
● Needing to pee more than usual, particularly at night.
● Feeling very tired or low on energy for no clear reason.
● Losing weight without trying, sometimes quite quickly.
● Blurred vision, as high blood sugar can affect the lenses of the eyes.
● Cuts and wounds healing more slowly than they normally would.
● Recurrent infections, such as thrush, or itching around the genitals.
● Tingling or numbness in the hands or feet, which can occur when blood sugar has been high for some time. [3]
Not everyone experiences all of these, and some people have symptoms so mild they go unnoticed. [1] Having one or two occasionally is not necessarily a cause for concern, but persistent symptoms, or several occurring together, are worth checking with a clinician.
"One of the challenges with type 2 diabetes is that symptoms often develop so gradually that people simply adapt to them or put them down to getting older, being busy or feeling run down. Increased thirst, tiredness or needing to pass urine more frequently can easily be overlooked. That's why early testing is so important. Identifying diabetes or prediabetes before complications develop gives us the best opportunity to protect long-term health and, in many cases, prevent progression through timely lifestyle changes and treatment."
— Dr Saira Bano, GP & Co-Founder, SwiftDoctor
How do symptoms differ between type 1 and type 2 diabetes?
While the core symptoms overlap, the way they appear is often quite different between the two main types.
Type 1 diabetes symptoms tend to develop quickly, over a matter of days or weeks, and are usually more pronounced. [2] Because the onset is rapid, they are harder to ignore, though they can sometimes be mistaken for another illness. Type 1 is most often diagnosed in children and young adults, but it can begin at any age.
Type 2 diabetes symptoms, by contrast, typically develop gradually, sometimes over months or years, and can be so mild that they go unnoticed for a long time. [1] It is more common in adults, particularly later in life, though it is increasingly seen in younger people too. A significant number of people with type 2 diabetes have no obvious symptoms at all and are only diagnosed through a routine blood test.
What causes diabetes symptoms to happen?
Most diabetes symptoms are the direct result of too much glucose (sugar) building up in the blood. Normally, a hormone called insulin moves glucose out of the bloodstream and into your cells to be used for energy. In diabetes, this system does not work properly, so glucose stays in the blood instead.
When blood sugar rises too high, the kidneys work overtime to filter and remove the excess, drawing water from the body in the process. This is what drives the two most recognisable symptoms: frequent urination, and the intense thirst that follows as the body becomes dehydrated. [3] Tiredness and weight loss happen because the cells cannot access the glucose they need, so the body starts burning fat and muscle for energy instead.
The underlying reason the system fails differs between the two types. In type 1 diabetes, the immune system attacks the cells that produce insulin, so little or no insulin is made. [2] In type 2 diabetes, the body either does not produce enough insulin or cannot use it effectively, known as insulin resistance. [1] Either way, glucose builds up in the blood and symptoms follow.
When should you see a doctor about possible diabetes symptoms?
As a general rule, speak to a doctor if you have any of the common symptoms above and they are persistent, particularly unexplained weight loss, ongoing fatigue, or excessive thirst and urination. There is no need to wait until symptoms are severe; getting checked early is always sensible.
Some symptoms, however, need urgent attention. If diabetes is left untreated, it can lead to a serious condition called diabetic ketoacidosis (DKA), a medical emergency that is more common in type 1 diabetes. [4] Warning signs of DKA include being very thirsty and passing a lot of urine alongside feeling sick or vomiting, tummy pain, fast or deep breathing, breath that smells fruity or sweet (like pear drops or nail polish remover), and drowsiness or confusion. [4]
If you or someone else has these symptoms, seek urgent medical help by calling 999 or going to A&E, especially if diabetes has not yet been diagnosed. [4] Early diagnosis and treatment consistently lead to better long-term management and a lower risk of complications, so acting sooner rather than later genuinely matters.
How is diabetes diagnosed?
Diabetes is diagnosed with a simple blood test, and often more than one, carried out and interpreted by a clinician. [1]
The most common is an HbA1c test, which reflects your average blood sugar level over the previous two to three months and does not require fasting. A blood glucose test, which measures the glucose in your blood at a given moment, may also be used, either while fasting or at a random time. In some cases, an oral glucose tolerance test, which checks how your body handles sugar over a couple of hours, is carried out as well. [1]
What matters is that these results are always interpreted in the context of your individual circumstances. A single reading is not the whole story, and a clinician will consider your symptoms, risk factors and medical history alongside any test results before confirming a diagnosis. A simple blood test can measure your blood sugar and the other relevant markers, with your results reviewed by a clinician.
What happens if you are diagnosed with diabetes?
A diabetes diagnosis can feel daunting, but it is far more manageable than many people fear, and it marks the start of a clear care pathway rather than a crisis. [1] What treatment looks like depends on the type of diabetes and your individual circumstances.
Type 1 diabetes is always treated with insulin, which replaces what the body can no longer produce, alongside support to manage blood sugar day to day. Type 2 diabetes is usually managed first through lifestyle changes, including healthier eating, more physical activity and, where relevant, weight loss, often alongside medication such as metformin. [5] Some people with type 2 diabetes eventually need insulin or other injectable treatments too.
Because excess weight is closely linked to type 2 diabetes, losing weight can significantly improve blood sugar control and, for some people, even lead to remission. [5] GLP-1-based treatments can play a role here for some patients: Mounjaro, which is licensed for type 2 diabetes as well as weight management, and Wegovy, used for weight management, are examples, though whether either is appropriate is always a clinical decision. The key point is that a diagnosis is the beginning of a manageable, ongoing process, and you are not expected to navigate it alone.
"A diagnosis of diabetes can feel overwhelming at first, but it is a condition that can be managed very successfully with the right support. Modern treatments, regular monitoring and sustainable lifestyle changes enable many people to live full, healthy lives while reducing their risk of complications. The most important thing to remember is that you don't have to navigate it alone. Working with healthcare professionals to create a personalised management plan can make all the difference."
— Dr Saira Bano, GP & Co-Founder, SwiftDoctor
How can a private GP help if you're worried about diabetes symptoms?
Diabetes testing and care, including treatments such as GLP-1 medication where appropriate, are available on the NHS, and for many people that is the right route. But if you have noticed possible symptoms and want answers quickly, a private GP service can help you get assessed and tested without a long wait. A SwiftDoctor consultation lets you talk through your symptoms with a qualified clinician promptly, arrange the appropriate blood tests, and have your results interpreted properly.
For many people, the hardest part is the uncertainty, so being able to speak to a clinician soon after symptoms appear can be reassuring in itself, whether the outcome is a clear explanation, a diagnosis, or simply peace of mind. Our clinicians take a calm, thorough and non-alarmist approach, and if a diagnosis is confirmed, you will have support to understand what it means and what happens next.
Frequently asked questions
What is usually the first sign of diabetes?
There is no single first sign that applies to everyone, but increased thirst and needing to urinate more often, especially at night, are among the most common early symptoms. [1] Persistent tiredness and unexplained weight loss are also frequent early indicators. Because symptoms can be subtle, they are easy to put down to other things at first.
Can you have diabetes with no symptoms at all?
Yes, particularly with type 2 diabetes. Many people have no obvious symptoms, or symptoms so mild they go unnoticed, and are only diagnosed through a routine blood test. [1] This is one reason testing is worthwhile if you have risk factors, even when you feel well.
How quickly do type 1 diabetes symptoms develop?
Type 1 diabetes symptoms usually develop quickly, over a few days or weeks, and tend to be more pronounced than in type 2. [2] Because onset is rapid and can lead to diabetic ketoacidosis if untreated, type 1 symptoms should always be checked promptly.
What blood test is used to diagnose diabetes?
Diabetes is diagnosed using blood tests, most commonly an HbA1c test, which reflects your average blood sugar over the past two to three months, and blood glucose tests taken while fasting or at random. [1] An oral glucose tolerance test is sometimes used as well, and a clinician interprets the results alongside your symptoms and history.
Can diabetes symptoms come and go?
Symptoms can vary in intensity, particularly in type 2 diabetes where they develop gradually and may be mild. However, symptoms that come and go should not be ignored or assumed to have resolved. [1] If you have noticed diabetes symptoms at any point, even intermittently, it is worth getting checked rather than waiting to see if they return.
Sources
[1] NHS, "Type 2 diabetes: Symptoms and how it's diagnosed", https://www.nhs.uk/conditions/type-2-diabetes/symptoms/
[2] NHS, "Type 1 diabetes: Symptoms and how it's diagnosed", https://www.nhs.uk/conditions/type-1-diabetes/symptoms/
[3] Mayo Clinic, "Diabetes symptoms: When diabetes symptoms are a concern", https://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/diabetes-symptoms/art-20044248
[4] NHS inform, "Diabetic ketoacidosis (DKA)", https://www.nhsinform.scot/illnesses-and-conditions/diabetes/diabetic-ketoacidosis-dka/
[5] NHS, "Diabetes", https://www.nhs.uk/conditions/diabetes/
