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Signs of Diabetes

  1. What are signs of diabetes?
  2. Type 1
  3. Type 2
  4. Other types
  5. Early signs of diabetes
  6. Diagnosis
  7. Prevention
  8. FAQs

What are signs of diabetes?

Signs of diabetes are the observable manifestations of diabetes, a condition that causes a person’s blood sugar levels to become too high.

There are two main forms of diabetes: type 1 and type 2. Type 2 diabetes is by far the most common, accounting for 90 percent of all cases of diabetes in North America and Europe.[1]

Diabetes is a chronic condition, typically requiring lifelong monitoring, management and treatment. This will usually involve a mixture of lifestyle changes and medications, though the exact methods will depend on the type of diabetes experienced. Though complications are possible, the majority of people with diabetes are able to manage the condition successfully and lead normal lives.[1]

The signs and symptoms of type 1 and type 2 diabetes are largely the same. The onset of type 1 diabetes, however, tends to be far more rapid than type 2 diabetes, which generally presents over a number of months or years. What’s more, the reason(s) why they develop may be different and may differ from person to person.

Read more about Diabetes »

Signs of type 1 diabetes

Type 1 diabetes develops when the pancreas, a glandular organ responsible for the production of a number of important hormones, ceases to produce insulin, a hormone that, among other functions, helps the body to absorb glucose. This causes blood sugar levels to become too high. It is most commonly diagnosed in children and young adults, though it can affect people of any age and will typically require lifelong management.[2]

Signs of type 1 diabetes include:[2][3]

  • Excessive thirst
  • Increased need to urinate
  • Tiredness
  • Weight loss
  • Blurred vision
  • Generally feeling unwell
  • Nausea and vomiting
  • Abdominal pain

The symptoms of type 1 diabetes typically appear relatively quickly over a number of days or weeks and settle down soon after treatment has begun.[2] However, if treatment is not received, glucose levels can become very high. This can lead to dehydration and/or drowsiness, and can be life-threatening.

Although type 1 diabetes cannot be cured, it can be managed effectively. Treatment involves daily monitoring of blood glucose levels, typically using a monitor at home. On average, two to four measurements will need to be taken daily, normally prior to meals, one to two hours after meals and before bed. When glucose levels are too high, insulin injections will be necessary.[2]

Doctors and specialists will provide advice on how to properly administer insulin. Most people with type 1 diabetes will need between two and four insulin injections per day, with the amount of insulin necessary dependent on factors such as the person’s level of activity and diet.

People displaying possible signs of type 1 diabetes should see a doctor for evaluation. In addition, the free Ada app can be used to carry out a symptom assessment.

Signs of type 2 diabetes

Type 2 diabetes develops when the body ceases to make enough insulin; the body’s cells do not use insulin as they should, this is called insulin resistance, or a combination of the two. The condition is far more common than type 1 diabetes and is particularly prevalent in mature adults, typically those over the age of 40.[4] People of any age can develop type 2 diabetes, however, and it is becoming increasingly common for younger people to develop the condition.

Signs that a person may be at risk of type 2 diabetes include:[4]

  • Having a family history of type 2 diabetes
  • Being overweight or obese
  • Having prediabetes, when glucose levels are higher than normal, but not high enough to constitute diabetes
  • Having had diabetes or prediabetes or diabetes during pregnancy

Signs and symptoms of having type 2 diabetes include:[1][4][5]

  • Increased need to urinate
  • Excessive thirst
  • Increased hunger
  • Tiredness
  • Weight loss
  • Blurred vision

In contrast to type 1 diabetes, the symptoms of type 2 diabetes will typically develop gradually over time, sometimes over a number of months or years. Due to this, it may be difficult to detect the condition and seek appropriate medical attention. Furthermore, in cases where glucose levels are not extremely high, no symptoms at all may develop.[4] If this is the case, the condition may only be diagnosed following tests for other conditions.

Treatment of type 2 diabetes generally centers on establishing and maintaining a healthy diet and getting sufficient amounts of exercise. In some cases, medication to help the body better respond to insulin may also be prescribed.[5]

People displaying possible signs of type 2 diabetes should see a doctor for evaluation. In addition, the free Ada app can be used to carry out a symptom assessment.

Read more about Type 2 Diabetes »

Other types of diabetes

Although type 1 and type 2 are by far the most common forms of the conditions, other types of diabetes also exist. In some cases, these rarer types of diabetes are classified as subtypes of type 1 or 2.

Signs of diabetes in pregnancy: gestational diabetes

Gestational diabetes is diabetes that occurs for the first time during pregnancy. The condition presents risks such as premature birth, miscarriage and the need for a cesarean section, though with proper management, these risks can be significantly reduced.[6]

Signs that a pregnant woman may be at risk of gestational diabetes include:[6]

  • Having experienced the condition during previous pregnancies
  • Having a high body mass index (BMI) before pregnancy
  • Having had one or multiple previous pregnancies
  • Having previously experienced stillbirth
  • Having previously given birth to a baby with a very high birth weight, typically 4.5 kg or more
  • Having a family history of diabetes
  • Having polycystic ovary syndrome
  • Being of South Asian, Caribbean or Middle Eastern descent

Gestational diabetes does not typically cause any signs or symptoms and will only be detected as a result of routine testing. However, in some cases, signs and symptoms may include:[7]

  • Excessive thirst
  • Increased need to urinate
  • A dry mouth
  • Tiredness

These signs and symptoms, however, can also be normal features of pregnancy and do not necessarily mean that gestational diabetes has developed. If they are being experienced, pregnant women should talk to their doctor or midwife who will be able to identify the root cause.

Read more about possible Pregnancy Complications

Signs of type 3 diabetes (Alzheimer’s disease)

There is evidence to suggest that Alzheimer’s disease represents a type of diabetes that selectively affects the brain.[8] This is because, in some cases, the progression of Alzheimer’s may be linked to insulin resistance. It is proposed, therefore, that the condition should be referred to as type 3 diabetes.

A person in the early stages of type 3 diabetes may not have elevated blood sugar levels. Instead, they may display signs and symptoms traditionally associated with Alzheimer’s disease including:[9]

  • Memory loss that disrupts day-to-day life
  • Difficulty planning and problem solving
  • Visual difficulties
  • Forgetting words, phrases or names
  • Mood and personality changes

Symptoms may differ from person to person. These symptoms may also not be a sign of Alzheimer’s disease, but a sign of another condition or simply the natural process of ageing.

If you or a loved one are displaying possible signs of Alzheimer's disease, consult a doctor for evaluation. In addition, the free Ada app can be used to carry out a symptom assessment.

Signs of maturity onset diabetes of the young (MODY)

Maturity onset diabetes of the young (MODY) is a rare hereditary form of diabetes caused by the mutation of a single gene. If a parent has the mutation, they stand a 50 percent chance of passing the condition to each one of their children.[10]

MODY is classified by some as a subtype of type 2 diabetes. However, it differs from type 2 diabetes in areas including the age at which it is typically diagnosed – usually below the age of 25 in MODY, over the age of 40 in type 2, also, the number of genes involved – one, as opposed to multiple – and the way in which it is passed on. MODY is inherited, whereas only the risk of type 2 diabetes is inherited.[11]

In many cases, the signs and symptoms of MODY are mild, and the condition may go unnoticed, only to be identified through routine testing or testing for another condition. If there are symptoms, they are typically similar to other types of diabetes, including:[11]

  • Excessive thirst
  • Increased need to urinate
  • Weight gain
  • Slow healing of wounds
  • Frequent infections

Signs of diabetes in babies: neonatal diabetes

Neonatal diabetes is a very rare form of diabetes, typically diagnosed in children under six months of age. The condition is caused by a gene mutation.

Signs and symptoms of neonatal diabetes include:[12]

  • Excessive thirst
  • Frequent urination
  • Dehydration

There are two types of neonatal diabetes: permanent neonatal diabetes mellitus (PNDM) and transient neonatal diabetes mellitus (TNDM). In cases of TNDM, the condition will normally develop shortly after birth – usually within a number of weeks – and disappear within a few months. Relapse, however, is possible, and diabetes may return in adolescence or adulthood. In cases of PNDM, diabetes is experienced for life.[13]

Early signs of diabetes

Due to the symptoms of type 1 diabetes generally appearing very quickly, there will typically be no pre-warning signs to indicate that the condition may develop. The typically gradual onset of type 2 diabetes, however, means that there may be certain early signs that develop over a number of months or years.

Due to the gradual onset of these early signs and symptoms, they may be difficult to detect. If there is any suspicion of diabetes, a doctor should be consulted as soon as possible. In addition, the free Ada app can be used to carry out a symptom assessment.


Prediabetes, or impaired glucose tolerance, is diagnosed when a person’s glucose levels are higher than normal, but not yet high enough to constitute diabetes. Prediabetes is an early warning sign of diabetes, as people with prediabetes are at increased risk of developing the condition in the future.

The risk factors for prediabetes are generally the same as those for type 2 diabetes, i.e. being overweight or having a family history of the condition, for example. It is most often asymptomatic, meaning that it is commonly only detected following a routine blood test or one ordered for a different purpose.[14] People concerned that they may be at risk of prediabetes should speak to their doctor. The free Ada app can also be used to carry out a symptom assessment.

If prediabetes is detected and treated effectively, this may prevent the onset of full-scale diabetes. Treatment will generally involve lifestyle changes, such as losing weight and diet alterations, as well as medication in some cases.[14]

Diabetes diagnosis

According to the World Health Organisation (WHO), diagnosing diabetes should first involve an evaluation of the symptoms being experienced. Following this, tests to measure blood glucose levels should be undertaken. A reading of 11.1 mmol/l normally or 7.0 mmol/l after fasting, or HbA1c of 48 mmol/mol (6.5%) or over will typically indicate diabetes. To confirm the diagnosis, multiple tests will generally be necessary – sometimes after a period of fasting – especially if no symptoms are present.[15][16] Doctors will provide information on how to fast safely and prepare for the tests.

Read more about diagnosing diabetes »

Diabetes prevention

Only type 2 diabetes is preventable. This is because this type of diabetes is commonly caused or exacerbated by unhealthy lifestyle choices.

Adopting a healthy, balanced diet is the most important factor in helping to prevent type 2 diabetes. This should be a diet low in carbohydrates, sugar and fat, and high in fruits, vegetables and grains.[17]

Other ways to help prevent type 2 diabetes include:[17]

  • Losing weight
  • Exercising regularly
  • Stopping smoking
  • Reducing alcohol intake

Read more about how to prevent diabetes »

Signs of diabetes FAQs

Q: Is there a difference in the signs of diabetes between men and women?
A: Generally, men and women experience the same signs and symptoms of diabetes. However, though sexual dysfunction can be a symptom for both sexes, the way in which this is experienced differs. Many males with diabetes suffer erectile dysfunction and impotence, while women may experience vaginosis, cystitis, problems with viginal lubrication, pain during sex and difficulty reaching an orgasm.[18][19]

Q: What are the signs of diabetes in the feet?
A: Both diabetes types 1 and 2 can cause damage to the feet. In severe cases, this may lead to the need to amputate. As such, people with diabetes should check their feet each day and look for the early warning signs of foot problems. These warning signs may include:[20]

  • Numbness, tingling or pins and needles in the feet
  • Pain or a burning sensation in the feet
  • A dull ache in the feet
  • Swollen feet
  • The feet cease to sweat
  • Wounds don’t heal on the feet
  • Cramp in the calves

If any of these signs develop, the affected person should consult a doctor. If any of the following signs are noticed, the affected person should consult their doctor as a matter of particular urgency:[20]

  • The feet change color or shape
  • The feet are hot or cold
  • There are cuts and/or blisters on the feet, but they cannot be felt
  • A wound on the feet is giving off a foul smell

Problems in the feet can develop very quickly, meaning it is important to seek help urgently when the warning signs appear.

Q: Can the early signs of diabetes be reversed?
A: People diagnosed with prediabetes – an early warning sign for diabetes – can take steps to lower their blood glucose levels. This may help to prevent the onset of diabetes in its full form. Lifestyle changes that may help with this include:[14]

  • Eating a healthy, balanced diet that is low in fat and high in fibre, fruits and vegetables
  • People who are overweight or obese should aim to lose weight
  • Undertaking regular physical exercise
  • People who smoke should stop

Doctors may also recommend the use of medications in some instances.

Q: Is there a type 3 diabetes?
A: Yes, Alzheimer’s disease is sometimes referred to as type 3 diabetes. Although the science behind this is not yet certain, there is evidence to suggest that the progression of Alzheimer’s disease may be linked to insulin resistance. For more information, see the above section on type 3 diabetes.

Q: Is type 2 diabetes more common than type 1?
A: Yes, type 2 diabetes is by far the most common type of diabetes, accounting for an estimated 90 percent of all cases in Europe and North America.[1] Although traditionally most associated with older people, especially older males, type 2 diabetes is becoming increasingly common in adolescents and young adults.[21]

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  2. Patient. “Type 1 Diabetes.” September 27, 2017. Accessed June 12, 2018.

  3. UpToDate. “Patient education: Diabetes mellitus type 1: Overview (Beyond the Basics).” February 27, 2017. Accessed June 12, 2018.

  4. Patient. “Type 2 Diabetes.” September 27, 2017. Accessed June 13, 2018.

  5. Diabetes. “Type 2 Diabetes.” Accessed June 13, 2018.

  6. Patient. “Diabetes and Pregnancy.” November 18, 2016. Accessed June 13, 2018.

  7. NHS Choices. “Gestational diabetes.” August 5, 2016. Accessed June 13, 2018.

  8. NCBI. Alzheimer's Disease Is Type 3 Diabetes–Evidence Reviewed. November, 2008. Accessed June 13, 2018.

  9. Diabetes Self-Management. “Type 3 Diabetes Symptoms.” September 6, 2017. Accessed June 14, 2018.

  10. Diabetes UK. “Maturity onset diabetes of the young (MODY).” Accessed June 14, 2018.

  11. The Diabetes Council. “Maturity-Onset Diabetes of the Young (MODY).” March 6, 2018. Accessed June 14, 2018.

  12. Diabetes. [“Neonatal diabetes.”(https://www.diabetes.co.uk/neonatal-diabetes.html) Accessed June 14, 2018.

  13. Orphanet. “Neonatal diabetes mellitus.” March, 2007. Accessed June 14, 2018.

  14. Patient. “Pre-diabetes.” September 21, 2017. Accessed December 11, 2018.

  15. Diabetes UK. “Diagnostic criteria for diabetes.” Accessed June 14, 2018.

  16. World Health Organisation. “Definition and diagnosis of diabetes mellitus and intermediate hyperglycaemia.” 2006. Accessed June 14, 2018.

  17. Diabetes. “Prevention of Diabetes Mellitus.” Accessed June 14, 2018.

  18. Diabetes. “Diabetes and Erectile Dysfunction.” Accessed June 14, 2018.

  19. Diabetes. “Sexual Dysfunction in Women.” Accessed June 14, 2018.

  20. Diabetes UK. “Know the signs of a serious foot problem when you have diabetes.” Accessed December 11, 2018.

  21. The Lancet. “Type 2 diabetes in adolescents and young adults.” August 25, 2017. Accessed December 11, 2018.