In a person with diabetes, the body stops producing insulin or can no longer produce or use it effectively. As a result, blood sugar levels rise, leading to various symptoms and complications.

Insulin is essential for processing glucose and enabling it to enter the cells of the body, where it provides energy.

People with type 1 diabetes do not produce insulin at all, because their immune system has attacked and destroyed the cells in the pancreas that produce insulin.

Those with type 2 and gestational diabetes do not make enough insulin, or their body cannot use it effectively.

Recognizing and treating the symptoms of diabetes early can help a person manage blood sugar levels. Preventing high glucose can prevent complications from developing.

For an overview of everything you need to know about diabetes, click here.

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Fatigue is a common symptom of diabetes.

Type 1 diabetes symptoms often appear rapidly, over a number of weeks. Type 1 often starts in childhood or adolescence, but it can occur at any age.

Type 2 usually develops over a number of years and usually starts after the age of 45 years, although it can appear earlier.

They are different conditions, but they both involve problems with insulin, which leads to an inability to process blood sugar, or glucose.

As a result, there will too much glucose in the blood and too little energy in the body’s cells.

The symptoms of diabetes include:

  • blurred vision
  • fatigue
  • increased hunger and thirst
  • frequent urination
  • numbness or tingling in the hands and feet
  • sores that do not heal
  • unexplained weight loss

Many of these symptoms occur as a result of the body trying to generate energy despite reduced or misused blood sugar.

For example, a person may experience fatigue and hunger because they cannot absorb enough energy from the foods they eat. They may urinate and feel thirsty more often, as too much glucose can cause the body to get rid of large amounts of fluid.

Some people with type 2 and gestational diabetes may not show symptoms. Their doctor might identify high blood sugar levels by performing a blood glucose test or a hemoglobin A1C test. However, if blood glucose levels rise too far, symptoms will appear. In addition, persistent high blood sugar can lead to serious complications.

Anyone who believes they might have symptoms of diabetes should speak to a doctor.

A person can check their own blood glucose levels at home, using a glucose monitor. These are available for purchase online.

Having too much sugar in the blood — known as hyperglycemia — is toxic to the body.

It can lead to complications, including:

  • Heart disease: According to the Centers for Disease Control and Prevention (CDC), heart disease is the leading cause of death in people with diabetes. Diabetes can damage the blood vessels and lead to heart attack and stroke.
  • Neuropathy: High blood glucose levels can result in diabetic neuropathy, another name for nerve damage. There are different types of neuropathy, and they can affect any part of the body. Peripheral neuropathy is common in people with diabetes. It affects the feet and hands. Together with poor circulation, this results in poor wound healing. Infections and ulceration can develop. Without rapid treatment, tissue death can occur, and amputation may be necessary.
  • Gastroparesis: Damage to the vagus nerve, which sends signals to the digestive tract, can affect the stomach’s ability to empty. Symptoms include nausea, heartburn, weight loss, bloating, and loss of appetite.
  • Gum disease and dental decay: Diabetes reduces the ability of the mouth and gums to heal and fight infections. Medications for managing diabetes might also lead to dry mouth as a side effect. These factors increase the risk of tooth decay and oral infections.
  • Kidney disease: According to the Centers for Disease Control and Prevention (CDC), an estimated 33 percent of people with diabetes have chronic kidney disease. Diabetes can also damage blood vessels in the kidneys, impairing function. The kidneys play a vital role in balancing fluid levels and removing waste from the body. Kidney health is therefore vital for preserving overall health.
  • Infections: A person with diabetes is more prone to infections. It can take longer to recover, and the symptoms can become more severe more quickly than in people without diabetes. An untreated infection can lead to sepsis or other problems. People should take care to avoid any type of infection, where possible.
  • Vision problems: High blood sugar levels can damage the eyes and cause vision loss. Retinopathy affects blood vessels in the retina, behind the eye. Other problems include diabetic macular edema (DME), cataracts, and glaucoma. High blood pressure and high cholesterol — which often occur with diabetes — can make this worse. The CDC estimate that early treatment can prevent or reduce the risk of blindness in around 90 percent of people with diabetes.
  • Depression: Researchers have identified a strong link between diabetes and depression. While this may be a result of managing life with a chronic condition, they might also share similar mechanisms in the body. Diabetes and depression also often make each other worse when they occur at the same time.
  • Diabetic ketoacidosis: Very high blood sugar levels that last for a long time can lead to diabetic ketoacidosis (DKA), in which the blood becomes too acidic. This can be life-threatening without treatment. A dry mouth, shortness of breath, and fruity smelling breath are symptoms. A diabetic coma may result.
  • Hypoglycemia: Low blood sugar can occur in a person who uses insulin, for example, if they take too much for their current needs. A person can resolve this by eating something sweet. Without treatment, it can lead to a diabetic coma, which can be life-threatening.

Some of these can lead to a diabetic emergency, which needs immediate medical attention.

Not everyone with diabetes will experience these complications. However, they are more likely to occur if a person does not take action to prevent them including following the doctor’s instructions and managing their blood sugar levels.

Gestational diabetes

Gestational diabetes can occur during pregnancy. It usually resolves after an infant is born, but it also increases the risk of developing type 2 diabetes in the future.

However, despite the limited duration of gestational diabetes, it still has the potential to cause complications in both mother and child.

Women with gestational diabetes face a higher risk of preeclampsia, a type of high blood pressure that can lead to severe problems in pregnancy, including premature birth and seizures.

Infants born to mothers with gestational diabetes are usually larger and have a higher risk of birth-related trauma and congenital anomalies.

If pregnancy is on the horizon or currently in progress, talk to a doctor about gestational diabetes and ways to manage it.

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Exercise is a great way to reduce the risk of diabetes.

It is not possible to prevent type 1 diabetes. A healthful diet, regular exercise, avoiding smoking, and attending screening can help to prevent type 2.

However, even after having a diagnosis of diabetes, a person can take measures to slow the progression of the disease and prevent complications.

People with type 1 need to manage their glucose levels through treatment with insulin, but they should also make choices that enable them to stay healthy overall.

If a person receives a diagnosis of prediabetes or type 2, a healthful lifestyle can still help to slow the progression of diabetes and possibly reverse it.

Eating food that contains plenty of fiber and useful nutrients, rather than sugary drinks and processed foods — which provide calories but no have no nutritional value — is an effective way to moderate blood sugar. A low-sugar, heart-healthy diet, such as the DASH diet, can help.

Exercise is a great way to ensure that the body is using blood glucose and removing it from the blood. It also generally strengthens the heart and blood vessels, protecting it against some of the more severe complications of diabetes.

Avoiding tobacco use, drug misuse, and limiting alcohol intake can help reduce the risk of diabetes and its complications. These all put a strain on the kidneys, liver, and heart, and increase the risk of complications.

Weight management for people with a high BMI can help. A doctor can advise on this.

Regular health checks and screening can ensure timely treatment for high blood sugar levels or other features. For type 2, the CDC recommend starting screening from the age of 45 years or younger if a person has risk factors, such as a family history of diabetes or obesity.

Type 1 diabetes always causes symptoms. Type 2 and gestational diabetes may not produce symptoms. Effective managment of blood sugar levels can help manage and minimize symptoms.

When symptoms occur, they include exhaustion, nausea, frequent urination, hunger, thirst, numbness in the extremities, and blurred vision.

Without treatment, complications can develop. These can be severe and, on occasion, life-threatening.

Anyone who believes they have symptoms of diabetes or may be at risk of developing it should speak to a doctor.


I have type 1 diabetes. How do I manage these symptoms and avoid the more severe complications?


Most people with type 1 diabetes see an endocrinologist to help manage their glucose as effectively as possible.

Endocrinologists are the best source of information on newer interventionsm such as continuous blood glucose monitoring and closed loop pumps. They can help you decide what is best for you and your lifestyle.

As well as controlling glucose levels, your doctors will monitor you for complications, using routine eye exams, blood pressure check, and urine protein and cholesterol checks, alongside regular foot exams to detect neuropathy.

Not smoking is also critical to prevent complications.

Suzanne Falck, MD, FACP Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

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