10 Warning Signs of Diabetes You Should Not Ignore

If you're urinating more than usual, constantly thirsty, and losing weight without trying, get a fasting glucose or HbA1c test within the next one to two weeks. Those three symptoms together are a strong signal that your blood sugar is out of control.

You don't need all ten warning signs to act. Any combination of the symptoms below is enough reason to get tested, especially if you have a family history of diabetes, carry extra weight around your midsection, or are over 35.

The problem with diabetes is that it can quietly damage your blood vessels, nerves, kidneys, and eyes for years before you feel seriously unwell. Many people only find out they have it after complications are already present. Catching it early gives you a real shot at reversing prediabetes or managing diabetes before that damage sets in.

What Are the 10 Warning Signs of Diabetes?

These symptoms fall into three groups: your body struggling to manage fluid, your cells starving for energy despite high blood sugar, and early damage to small blood vessels and nerves. Knowing which group a symptom belongs to helps you understand why your body is sending that signal.

1. Frequent Urination

When blood sugar rises above a certain threshold, your kidneys can't reabsorb all that glucose. It spills into your urine and pulls water with it. You urinate more often and in larger amounts, including waking up multiple times at night.

One of my clients described it as feeling like she couldn't stay away from the bathroom for more than an hour. She'd put it down to drinking too much water. It was the other way around.

2. Excessive Thirst

Losing all that fluid through urination leaves you dehydrated. Your body responds by making you intensely thirsty. You drink more, urinate more, and the cycle continues.

This is called polydipsia, and it almost always pairs with frequent urination in undiagnosed diabetes.

3. Unexplained Weight Loss

Losing weight without dieting sounds like good news. It's not. When your cells can't access glucose for energy because insulin is absent or ineffective, your body breaks down fat and muscle instead.

Type 1 diabetes in particular can cause rapid, significant weight loss over just a few weeks as beta-cell destruction accelerates.

4. Extreme Fatigue

Your cells are starving. Even though there's plenty of glucose in your blood, it can't get into your cells without functioning insulin. The result is persistent, deep fatigue that doesn't improve with rest.

I know this because it happened to me and I initially wrote it off as stress and poor sleep. It was only after testing that the real cause became clear.

5. Blurred Vision

High blood sugar pulls fluid out of the lenses of your eyes, changing their shape and your ability to focus. Vision can fluctuate throughout the day depending on blood sugar levels.

This is different from needing new glasses. If your vision is shifting and you have other symptoms on this list, blood sugar is worth checking before you book an optometrist.

6. Slow-Healing Cuts and Sores

High glucose impairs circulation and weakens the immune response, meaning wounds that should close in a few days take weeks. This is especially common on the feet and lower legs where circulation is already challenged.

One of my clients had a small blister from new shoes that took nearly six weeks to fully heal. That was the red flag that led to her diagnosis.

7. Frequent Infections

Bacteria and fungi thrive in a high-glucose environment. Recurrent urinary tract infections, yeast infections, skin infections, and gum disease are all more common when blood sugar is chronically elevated.

If you keep getting infections that respond to treatment but keep coming back, elevated blood glucose may be the reason.

8. Tingling or Numbness in Hands and Feet

This is peripheral neuropathy, and it's one of the most telling signs that blood sugar has been high long enough to damage nerves. It often starts as a tingling or burning in the toes or fingertips.

A 2024 study of hand surgery patients found that 51.3% of those presenting with peripheral neuropathies of the hand tested positive for prediabetes, with no prior diagnosis. Many of those patients had no idea their blood sugar was an issue. The hand symptoms were the first clue.

9. Increased Hunger

This feels counterintuitive. You're eating, your blood sugar is high, yet you're still hungry. Because glucose can't enter your cells properly, your body sends hunger signals asking for more fuel.

This constant hunger despite eating normal amounts is called polyphagia and is a classic sign of energy dysregulation.

10. Dark Patches of Skin

Acanthosis nigricans is a darkening of skin in body folds, typically the neck, armpits, and groin. It looks like a dirty patch that doesn't wash off.

It's caused by insulin resistance driving excess insulin production, which stimulates skin cell growth. This is often one of the earliest physical signs of Type 2 diabetes and prediabetes, particularly in children and younger adults.

How Do You Feel When Diabetes Starts?

With Type 1 diabetes, the onset is fast. Symptoms come on hard over days to weeks as the immune system destroys insulin-producing beta cells. You feel acutely unwell.

With Type 2, it's much slower and easier to miss. In the early stages you might just feel a bit tired, a bit thirsty, and perhaps notice you're getting up once at night to urinate. Nothing dramatic. Nothing that makes you think to get a blood test.

That vagueness is exactly what makes Type 2 dangerous. By the time the symptoms feel serious, the disease has often been progressing for years.

What I found was that most people who come in for a diabetes screening had been experiencing at least two or three symptoms for months before they connected them. Fatigue plus thirst plus slightly blurry vision in the mornings. Each symptom seemed to have an innocent explanation on its own.

What Are 5 Signs Your Blood Sugar Is Too High Right Now?

If your blood sugar is acutely elevated, rather than chronically high over time, the most immediate signals are:

• Headache and difficulty concentrating as the brain struggles with abnormal glucose levels
• Dry mouth and intense thirst as osmotic pressure shifts fluid out of cells
• Frequent urination as your kidneys flush excess glucose
• Nausea or stomach discomfort which can occur with rapid blood sugar spikes
• Fatigue and a heavy, slow feeling as cellular energy drops despite high blood glucose

These can also be signs of diabetic ketoacidosis in Type 1 diabetes, which is a medical emergency. If these symptoms are severe or accompanied by fruity-smelling breath, vomiting, or confusion, seek emergency care immediately.

The Warning Signs Most Articles Get Wrong

A few things worth knowing that most diabetes symptom articles skip over entirely.

Musculoskeletal problems can be the first sign

Trigger finger, carpal tunnel syndrome, and peripheral neuropathies in the hand are increasingly recognized as early markers of undiagnosed dysglycemia. Most people with these conditions get treated for the joint or nerve issue without anyone checking their blood sugar.

If you have a hand or wrist condition that isn't responding to treatment the way it should, ask your doctor to run a glucose tolerance test. The 2024 research showing that over half of hand surgery patients with neuropathy had undiagnosed prediabetes is a striking example of how far upstream diabetes can cause problems before the classic symptoms appear.

Symptoms are not required for serious damage to be happening

Clinical guidelines recommend screening adults over 35 every three years regardless of symptoms. That's because microvascular damage to the kidneys and eyes can begin well before blood sugar is high enough to cause symptoms you'd notice.

Retinopathy, early nephropathy, and nerve damage can all be present at diagnosis in people who felt relatively fine. Waiting for symptoms is a losing strategy.

Prediabetes is reversible, diabetes is manageable but not reversible in most cases

This distinction matters enormously and is often understated. Prediabetes, where blood sugar is elevated but not yet at diabetic levels, can be fully reversed through diet, weight loss, and exercise.

Type 2 diabetes can be put into remission with significant lifestyle changes, but the underlying metabolic vulnerability remains. The earlier you catch it, the more options you have.

What Is the Red Flag of Diabetes?

If there's one combination that should send you straight to get tested, it's this: frequent urination plus excessive thirst plus unexplained weight loss. Together, these three reflect the core pathology of uncontrolled hyperglycemia and are present in both Type 1 and Type 2 diabetes when blood sugar is significantly elevated.

For Type 1, these symptoms can appear within days and escalate quickly. For Type 2, the same triad builds over months. Either way, this cluster is the red flag.

Who Should Get Tested Even Without Symptoms?

High-risk groups shouldn't wait for symptoms to appear. Get screened if you:

• Are over 35 years old
• Have a parent or sibling with diabetes
• Are overweight, particularly with weight carried around the abdomen
• Have a sedentary lifestyle
• Have previously had gestational diabetes
• Have been told you have polycystic ovary syndrome (PCOS)
• Belong to a higher-risk ethnic group including Aboriginal and Torres Strait Islander, Pacific Islander, South Asian, or Southeast Asian backgrounds
• Have high blood pressure or abnormal cholesterol levels

A fasting glucose test or HbA1c blood test is all it takes. Both are simple, inexpensive, and available through your GP.

FAQ

Can you have diabetes and feel completely normal?

Yes. Type 2 diabetes in particular can be present for years without obvious symptoms. Many people are diagnosed incidentally during routine blood tests or when they present with a complication like neuropathy or an eye problem.

This is why routine screening matters more than symptom-driven testing for people with risk factors.

What does early diabetes feel like?

In the early stages it often feels like general tiredness, mild thirst, and occasionally needing to urinate more than usual. None of these feel alarming.

Many people attribute them to stress, aging, or not drinking enough water. The symptoms build slowly and become more noticeable as blood sugar rises further.

What are the five strange symptoms of diabetes?

Beyond the well-known signs, less obvious symptoms include dark skin patches in body folds, recurrent yeast infections, trigger finger or carpal tunnel that keeps coming back, bleeding gums and slow-healing mouth sores, and fruity-smelling breath in Type 1 diabetes (a sign of ketones).

These get missed regularly because most people don't connect them to blood sugar.

How quickly do diabetes symptoms come on?

Type 1 diabetes can develop symptoms over days to a few weeks as the autoimmune process accelerates. Type 2 diabetes develops over months to years.

Many people with Type 2 can't pinpoint when their symptoms started because the changes were so gradual.

Is blurry vision always a sign of diabetes?

Blurry vision has many causes. But if it fluctuates throughout the day, comes alongside thirst and fatigue, and you haven't changed your glasses prescription recently, blood sugar is worth ruling out.

Fluctuating vision that tracks with meals or time of day is a more specific signal than stable blurriness.

Can diabetes be reversed?

Prediabetes can be fully reversed with lifestyle changes. Type 2 diabetes can go into remission with significant weight loss and dietary change, but this isn't guaranteed and the metabolic risk remains.

Type 1 diabetes can't be reversed as it involves permanent immune-mediated destruction of insulin-producing cells.

What to Do Now

If you recognized three or more symptoms in this article, book a fasting glucose or HbA1c test with your GP this week. Don't wait to see if the symptoms get worse.

If you have risk factors but no symptoms, ask your GP about routine screening. Adults over 35 should be tested every three years at minimum. High-risk groups should be tested sooner and more frequently.

If your result shows prediabetes, treat it seriously. That's your window to prevent full diabetes through diet, movement, and weight loss. The earlier you act, the more you protect your kidneys, eyes, heart, and nerves from damage that's much harder to undo.