Signs and Symptoms of Prediabetes

Medically reviewed by Dr Sultan Linjawi, Endocrinologist & Diabetes Specialist — December 2025

Part of:What is prediabetes or borderline diabetes and does it matter?
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Prediabetes often develops quietly, with symptoms that are easy to overlook or explain away as “age”, “stress”, or simply being busy. Yet early signs of rising glucose levels matter, because this is the stage where the risk of type 2 diabetes can still be reversed.

Most people with prediabetes feel no symptoms at all. That’s why screening is essential—especially if you have risk factors such as weight gain around the stomach, family history, or a history of gestational diabetes. But when symptoms do appear, they usually reflect the effects of insulin resistance, fluctuating blood glucose levels, or early metabolic changes.

To properly understand what’s happening, it helps to know how these symptoms relate to insulin resistance, the most common cause of prediabetes. If you’re uncertain about your risk, consider using the Diabetes Risk Calculator or joining the free Prediabetes & Insulin Resistance Masterclass, where Dr Sultan explains how to interpret symptoms and what to do next.

Early signs you may notice

Many symptoms of prediabetes relate to the body struggling to keep glucose levels in a healthy range. These can be subtle, inconsistent, or easy to attribute to lifestyle pressures.

1. Increased thirst

Mild dehydration can occur when excess glucose draws water into the urine. This isn’t usually as dramatic as in type 2 diabetes, but some people notice they are drinking more than usual, especially in the evenings or overnight.

2. More frequent urination

As blood sugars begin creeping higher—even within the “prediabetes” range—the kidneys may pass more urine to keep glucose under control. You might find yourself going to the toilet more often, particularly at night.

3. Increased hunger (even after eating)

If your body becomes less responsive to insulin, glucose does not move efficiently into the muscles for energy. This can trigger “cell-level hunger”, leading to cravings or overeating even when you have eaten enough.

To understand the background process, it can help to review:

For a simple overview of prediabetes and insulin resistance, the CDC also provides a helpful summary: CDC – Prediabetes Basics.

Skin, weight & hormonal symptoms

4. Darkening of the skin (acanthosis nigricans)

A velvety, darker patch of skin—commonly around the neck, underarms, or groin—can be a visible sign of high insulin levels. This is one of the strongest physical markers of insulin resistance and should always prompt further testing.

5. Weight gain around the stomach

Central or abdominal weight gain is strongly linked with worsening insulin sensitivity. Many people notice that their waistline increases even if they do not feel they are eating more than before. This “apple-shaped” pattern is closely associated with prediabetes and metabolic syndrome.

6. Polycystic ovary syndrome (PCOS) features

Prediabetes often coexists with polycystic ovary syndrome in women. Symptoms can include irregular or absent periods, acne, excess hair growth on the face or body, and difficulty losing weight. PCOS is strongly associated with insulin resistance, even when blood glucose levels are not yet in the diabetes range.

If you are concerned about underlying insulin resistance or metabolic health, you may find these resources helpful:

Energy, sleep & mood symptoms

Many people with prediabetes report feeling unusually tired, mentally foggy, or unrefreshed after sleep. These symptoms are often early metabolic warning signs, but they are easy to blame on work, family demands, or “just getting older”.

7. Fatigue and low energy

When glucose does not enter the cells efficiently, the body cannot generate energy optimally. This can lead to:

  • Persistent tiredness
  • “Brain fog” or feeling mentally slow
  • Difficulty concentrating or staying motivated

Many people only realise how affected they were once their glucose control improves. For a deeper dive into this topic, see: Why Do I Feel So Tired With Prediabetes?

8. Poor-quality sleep or sleep apnoea

Insulin resistance and obstructive sleep apnoea commonly occur together. Signs include loud snoring, pauses in breathing during sleep, waking unrefreshed, morning headaches, or needing daytime naps. Disturbed sleep further worsens insulin resistance, creating a vicious cycle.

9. Mood changes

Fluctuating glucose levels and chronic fatigue can affect mood, making it harder to cope with daily stresses. People with prediabetes may notice:

  • Irritability or feeling “on edge”
  • Low mood or loss of enjoyment
  • Increased anxiety or worry about health

If this resonates with you, you may also want to explore: Prediabetes and Mental Health.

If these symptoms feel familiar, Dr Sultan explains the underlying biology and practical next steps in the free Prediabetes & Insulin Resistance Masterclass. It’s a simple, no-jargon way to understand what is happening in your body and what you can do about it.

When should you get tested?

Testing is recommended if you notice any of the symptoms above—especially if you also have risk factors such as family history of type 2 diabetes, a history of gestational diabetes, abdominal weight gain, high blood pressure, or age over 40.

Common tests include:

  • Fasting plasma glucose
  • Oral Glucose Tolerance Test (OGTT)
  • HbA1c (best interpreted alongside other tests, not in isolation)
  • In some cases, specific tests for insulin resistance

You can read more about how prediabetes is diagnosed here:

The NIDDK also provides an overview of prediabetes and testing approaches: NIDDK – Prediabetes & Insulin Resistance.

What should you do next?

If you recognise these symptoms, the most important step is not to ignore them. Prediabetes is the stage where lifestyle changes have the greatest impact and reversal is genuinely possible.

Good next steps include:

Remember: it is not “having prediabetes” that causes most of the long-term harm, but living for years with elevated blood sugars and unrecognised insulin resistance. Acting early makes all the difference.

Free Prediabetes & Insulin Resistance Masterclass

If you would like a clear, step-by-step explanation of what your symptoms mean, how to interpret your blood tests, and what to do next, you can join Dr Sultan’s free Prediabetes & Insulin Resistance Masterclass.

In around 40 minutes you’ll learn how to reduce your risk of type 2 diabetes, improve your energy levels, and build a practical plan you can actually stick to.

How this page fits into your learning

My Health Explained is designed to help you understand diabetes over time, not all at once. Most people arrive with one specific question, then build confidence as new questions come up.

This page covers one important part of that picture. You'll see links throughout to related topics that explain why things happen, what options exist, and what tends to help in real life.

If you'd like a broader overview first, start here: What is prediabetes or borderline diabetes and does it matter?.

If something here raises a question, follow the links that feel most relevant and ignore the rest for now. This resource is built to support learning at your own pace.

Explore key areas of prediabetes

These sections cover the main areas people with prediabetes commonly ask about.

What are the symptoms of diabetes mellitus?

Have you ever wondered what the symptoms of diabetes are? There are similarities across type 1 and type 2 diabetes, but there are also a few key differences too. People with all types of diabetes can, but not necessarily, have a shorter life expectancy. The presence of diabetes does not in itself lead to a shorter life, but rather having high blood sugar levels does. Having good control of sugar levels will cause a person with diabetes to live as full and healthy a life as anybody else. For this reason, it is important to understand and recognise any symptoms relating to diabetes. Diagnosing diabetes mellitus early can save your life in the short term but with proper management of the condition long term complications can be avoided too.

PreDiabetes Content
PreDiabetes Program
Overview
Risk Factors
Symptoms
Diagnosis
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Diabetes is a common condition affecting more and more people every day. In 2016, diabetes was the direct cause of death in 1.6 million people (WHO, 2018) worldwide. If we consider death from diabetes related conditions, it is estimated to lead to the death 4 million people every year around the world, more than malaria, TB, and HIV combined.

In diabetes mellitus, symptoms that you experience are related to:
a) the severity of diabetes, i.e. how high your blood glucose levels are,
and
b) how long you have had the condition, i.e. how long you have had high blood glucose levels for.

When a person initially develops type 1 diabetes, the beta cells of the pancreas rapidly fail to produce adequate amounts of insulin. Since there is little insulin, blood glucose levels rise very quickly. The symptoms of diabetes happen rapidly, are severe, and people notice that they are unwell quite quickly. If a person develops type 1 diabetes slowly, then these symptoms may take months to develop but often it is weeks.

In people with type 2 diabetes, the progression of the condition happens much more slowly, over the course of several years, so the symptoms happen slowly and are often subtle. You may not even notice anything at all, or you may even dismiss them as a normal part of growing older.

By the time that you notice something isn’t quite right, you could have been experiencing high blood glucose levels for years! Often people who are diagnosed with type 2 diabetes, have had diabetes for perhaps 5 years and borderline diabetes for many years before that.



What is the most common symptom in people with type 2 diabetes?

The most common sign of diabetes is…
Nothing.
That’s right. Nothing. The reason that doctors need to test for diabetes (and people need to demand it), is that most people have no idea that they have it. This regular testing is most important in people at the highest risk of developing diabetes.

If you want to learn how type 2 diabetes mellitus can affect men and women differently, we have also written dedicated articles to answer your questions:







What are the other symptoms of diabetes?

Fatigue and irritability

Fatigue is another common type 2 diabetes symptom. You may often feel tired, regardless of how much you have eaten, because your cells are not able to use the glucose that is broken down from the food.

If you’re needing to make a lot of trips to the bathroom at night, this can also disrupt your sleep. Waking up multiple times throughout the night could mean you aren’t able to get a restful sleep, leaving you to feel tired throughout the day. This ongoing fatigue can make you easily irritable. It’s no wonder why you may be feeling more grumpy than usual!


Excessive thirst, frequent urination, and dehydration

When your blood glucose levels are high, a lot of the glucose passes into the urine. Because you lose so much glucose in your urine, it also attracts water, meaning that you are making a lot of urine, causing you to need to pee a lot! If you are going to the toilet a lot and losing a lot of urine, then you are quickly becoming dehydrated. If you are dehydrated, you become thirsty. People who feel they need to constantly drink lots of water may have diabetes and it needs to be tested for.

If a person with high sugar tries to deal with their thirst by drinking sugar containing fruit juice or soft drinks, then the blood sugar can become even higher, resulting in even more sugar in the urine, even more urine production, and worsening dehydration. It’s a vicious cycle.



How high sugar levels lead to excessive urination and dehydration


Ongoing hunger

We get energy, like glucose, from the foods that we eat. People with diabetes, have little glucose entering the muscle cells, so the body will signal that it needs more food even though there is plenty in the blood. You may have ongoing hunger, regardless of how much you have already eaten, because the body is craving more energy.


Yeast and bacterial infections

Yeast and other fungi use glucose for energy and thrive in an environment that is high in sugar. Yeast infections can occur in both men and women. Infections can grow in any place on the body that is a warm, moist fold of the skin, including:

  • Between fingers and toes
  • Under breasts
  • In or around sex organs

People with high blood sugars also have a high risk of developing bacterial infections like urinary infections, chest infections, and skin infections and boils. The cells that fight infections are called neutrophils and their function is impaired if the glucose level is above 11mmol/l (or 200mg/dl).


Dry and itchy skin

When the body is dehydrated, our skin can become dry and feel itchy. Dry and itchy skin is more easily able to break, causing a cut or wound.


Cuts and wounds that don’t heal quickly

Neutrophils, white blood cells that fight any infection in our body, are sensitive to high blood glucose levels. These are a very important part of the immune system and are at the front line of a person's defences, keeping bacterial infections at bay. In a person with diabetes, the ability of neutrophils to fight infections decreases, causing you to be less likely to able to fight infections, like a cut or a wound found on your foot.


Pain and numbness in your feet or legs

Pain and numbness in the feet are another sign of high glucose levels and can indicate nerve damage. You might be experiencing pins and needles in your feet, a woolly sensation in the feet or pain. In a person with diabetes, if there is numbness in their feet, they may not even realise if they have a cut or a wound. This can lead to unrecognised damage that can spread and is the leading cause of amputation in people with diabetes.


Blurred vision

This is a common complaint. Blurred vision occurs when glucose enters the lens in the eye ball. This causes it to swell, changing its shape and changing the refraction. This leads to a change in your eyesight. Some people will develop blurred and others might even notice an improvement in the eye sight! When the glucose levels fall back to more normal levels the lens changes shape again leading to a change in the visual acuity and a person’s eyesight. Many people are picked up as having diabetes by the opticians when they go for an eye check but is important to not get new glasses until the glucose levels are stable.


Weight loss

If you have type 2 diabetes, there may come a time where you experience weight loss despite eating normally. This occurs when the glucose levels are very high and the pancreas is failing. This is a sign of severe diabetes. This results in not enough glucose being absorbed in the cells to be used for energy, so your body starts to breakdown fat and muscle instead, leading to the weight loss.



Are there other conditions associated with type 2 diabetes mellitus?

Type 2 diabetes is part of a group of disorders grouped together and known as the metabolic syndrome. Metabolic syndrome also includes high blood pressure, or hypertension, as well as disorders of cholesterol levels. Often people may have these conditions prior to being diagnosed with type 2 diabetes.



When to speak to your doctor?

If you experience any of the above symptoms it is important to get tested for diabetes as soon as possible. Some people are at higher risk and need regular testing if you are 45 years or older or have other risk factors for diabetes. By diagnosing and treating the condition early, it means you can decrease the risk of developing any further health complications of diabetes, for example nerve damage, blindness, and heart disease.



If you have already been diagnosed with diabetes and would like to know more about how best to manage the condition, you can join our personalised 12 week diabetes program. The first week is free!



Interested in more information on type 2 diabetes?



If you want to learn more about diabetes, we have dedicated information pages: