Diabetes is a disease that changes the way the body processes blood sugar, typically for life. Untreated or poorly managed diabetes can lead to serious health problems.
Diabetes can cause or appear alongside a variety of health conditions. When this happens, they are called “co-occurring,” “co-existing,” or “comorbid” conditions.
A 2021 study in Ningbo, China showed that 93.7% of people with Type 2 diabetes developed or were diagnosed with a co-existing condition within 8 years of their diabetes diagnosis.
In this article, we take a look at the most common—and dangerous—complications of diabetes. We answer questions about conditions that occur alongside diabetes, including:
What is the difference between type 1, type 2, and gestational diabetes?
What conditions can appear alongside type 1 or type 2 diabetes?
What conditions can appear alongside gestational diabetes?
If I have diabetes, how can I lower my risk of developing other conditions?
Where can I get more information about diabetes?
What is the difference between type 1, type 2, and gestational diabetes?
Diabetes mellitus is a group of conditions that change the way the body processes glucose. Also known as blood sugar, glucose powers everything in our bodies: our brains, muscles, and tissues can’t function without the right amount of glucose.
Most often, the dangers of diabetes appear when there is too much sugar in your blood, a condition known as hyperglycemia. Left untreated, poorly managed diabetes can lead to serious health complications and comorbid conditions.
There are three main types of diabetes:
Type 1 diabetes mellitus (T1DM)
Type 2 diabetes mellitus (T2DM)
Gestational diabetes
Type 1 diabetes
Type 1 diabetes or T1DM is a chronic condition where the pancreas creates little or no insulin, the hormone the body uses to process glucose.
Previously called juvenile diabetes, type 1 diabetes typically appears in childhood or adolescence. While there is not a cure for type 1 diabetes yet, its symptoms can be managed with medication, insulin, exercise, and dietary changes.
Type 2 diabetes
Type 2 diabetes or T2DM is diabetes that appears later in life due to certain environmental, genetic, or lifestyle factors. These might include:
Poor diet.
Lack of exercise.
Obesity.
Family history. If someone in your family has type 2 diabetes, like a parent or sibling, you are at higher risk of developing T2DM yourself.
Age. T2DM is most common in people over 35.
Ethnicity. T2DM diagnoses appear at a slightly higher rate for people of African, American Indian, Asian, or Latine descent.
Gestational diabetes
Gestational diabetes appears during pregnancy and is often reversible. Hormonal changes in a pregnant person’s body can impact insulin production and glucose processing.
Like type 2 diabetes, lifestyle changes like eating a healthy diet, losing weight, and exercising can help prevent gestational diabetes. After the baby is born, your doctor might recommend these types of lifestyle changes to help bring your body back to its pre-pregnancy blood sugar levels.
Prediabetes
In addition, some doctors consider prediabetes, or unusually high blood sugar, a fourth type of diabetes. Someone with prediabetes does not have full-blown Type 2 but is at a high risk for developing the disease.
Luckily, lifestyle changes like improvements to diet and exercise can help people with prediabetes lower their risk of developing Type 2 diabetes or other related conditions.
What conditions can appear alongside Type 1 or Type 2 diabetes?
Type 1 and type 2 diabetes, especially when untreated or poorly managed, have been linked to multiple health problems and comorbid conditions.
These include issues with:
Dangerous blood sugar levels
Nerve damage
The heart and blood pressure
Eyes and vision
Hearing
Alzheimer’s disease and dementia
Uncontrolled weight changes
Mental health
The feet and legs
The kidneys and liver
Skin conditions
Cancer
Sleep
Let’s dive into these in detail.
Hyperglycemia and hypoglycemia
The most common issues associated with diabetes deal with blood sugar. Having too much sugar in your blood (**hyperglycemia**) or too little (**hypoglycemia**) can lead to dangerous health complications.
Severe hypoglycemia can lead to:
Chills and sweating
Clumsiness
Confusion
Double vision or blurry vision
Extreme hunger
Fainting spells
Shaking
Tingling, numbness, or weakness, particularly in the legs and feet
Meanwhile, severe hyperglycemia can lead to a life-threatening condition called diabetes-related ketoacidosis.
When this happens, your body doesn’t have enough insulin to process all the extra sugar. Instead, it turns to fat for energy by producing ketones, acids that help break down fat.
Too many ketones can make your blood turn acidic, which can be a life-threatening condition requiring emergency medical care.
A note on diabetes and the keto diet
You might have heard of ketoacidosis because of the ketogenic diet (or “keto”), a popular diet that cuts out sugar and carbohydrates in favor of high-fat food.
The body turns automatically to processing fat, which can help with weight loss and, in some cases, managing conditions like epilepsy.
While following the keto diet with diabetes can help control blood sugar levels, it can also be dangerous if you try the diet unsupervised, especially if you use insulin injections.
Always check in with your doctor before making any drastic changes to your diet or lifestyle.
Nerve damage
Too much sugar in your blood can damage the vessels that provide blood to your nerves. When blood flow cuts off from these nerves, the nerves can get injured or even die through a condition called diabetic neuropathy.
Diabetic neuropathy can cause:
Numbness
Tingling
Pain, usually a burning sensation
These symptoms appear most often in the hands, legs, and feet, although they can also affect major organs like the heart, kidneys, and liver.
Heart and blood pressure problems
Compared with someone without the condition, a person with T2DM is two times more likely to have a stroke or develop heart disease.
Diabetes can lead to:
High blood pressure** (hypertension).
Increased lipids in the blood** (dyslipidemia), which can cause heart disease, high cholesterol, or heart attacks.
Heart disease.** In addition to heart disease’s other symptoms, people with diabetes are more likely to die during a heart attack compared to people without the condition.
Peripheral artery disease**, or reduced blood flow to the legs and arms.
Eye damage
People with diabetes are at a higher risk of developing eye diseases and conditions like:
Deafblindness (when combined with diabetic hearing loss
Diabetic retinopathy
Macular degeneration (also called diabetic macular edema)
Excess blood sugar can cause tiny, open sores called eyelid styes on the inside or outside of your eyelids. Eyelid styes are not dangerous on their own, but they’re usually annoying and painful—and can impact your vision if they grow too big or get infected.
All that glucose can also cause damage to the blood vessels that fuel the retina, the part of our eye that processes light. This condition, called diabetic retinopathy, causes symptoms like:
Dark spots or “floaters” in your vision
Blurry vision
Vision loss or low vision
Left untreated, diabetic retinopathy can lead to severe or total vision loss that can’t be fixed with glasses or surgery. If you have diabetes, make sure to keep up with annual eye appointments to check for the early signs of diseases like diabetic retinopathy.
Hearing impairment
According to the American Diabetes Association, people with diabetes are two times more likely to develop hearing loss.
While researchers aren’t 100% sure why this happens, some theories suggest that high blood sugar damages the sensitive blood vessels in the inner ear, in the same way diabetes damages the kidneys and liver.
This type of damage can lead to auditory disabilities like tinnitus, constant ringing in the ears. Left untreated, nerve damage in the ears can make people with diabetic hearing loss become fully deaf.
To learn more about the different types of hearing loss, see Deafness, Types of Hearing Loss, and What Causes Each.
For more hearing loss resources, see the Auditory Disabilities section of the Ability Central resource Portal.
Alzheimer’s disease and dementia
Because both diabetes and Alzheimer’s disease are related to insulin resistance, recent research suggests a link between diabetes and dementias like Alzheimer’s. Some professionals even call Alzheimer’s disease “diabetes type 3” because of this strong link.
The strongest link is between diabetes and Alzheimer’s, but diabetes can also lead to or complicate other forms of dementia, like Lewy body dementia and vascular dementia.
Dangerous weight changes
Diabetes has been linked to both weight loss and weight gain. Both type 1 and type 2 diabetes can lead to:
Sudden, unexpected weight loss. Losing weight without trying can be an early symptom of type 1 diabetes or a response to medication changes for type 2 diabetes.
Eating disorders, especially when someone under-treats their diabetes to lose weight.
Weight gain when starting medications, particularly insulin.
Obesity, when someone has so much extra weight or fat in their body that it affects their health. Obesity can be a cause of, result of, or co-occurring condition with diabetes.
Mental health issues
Diabetes can be a frustrating, frightening, or isolating condition. Many people with diabetes must make drastic changes to their diets or lifestyles, and their loved ones might not be on board right away. Plus, the complications from diabetes can be exhausting, scary, or even embarrassing.
Research shows a strong link between diabetes and mental health issues like:
Anger
Anxiety
Depression
Stress
Suicidal ideation
Take time to regularly check in on mental health for yourself or your loved ones with diabetes. Organizations like Netflix’s Wanna Talk About It program offer excellent mental health resources. You can also use Ability Central’s Service Locator tool to find organizations near you offering support for diabetes.
Foot damage
Another form of diabetic nerve damage called peripheral neuropathy can cause major harm to the feet, which are often at the most risk for people with diabetes.
Peripheral neuropathy, reduced blood flow, and other issues can lead to diabetic foot syndrome, a common problem that can become dangerous if left untreated.
Diabetic foot syndrome symptoms include:
Foot ulcers, a type of open sore.
Cramps or pain in your feet and legs, including the thighs and buttocks.
Numbness, burning, or tingling in your feet.
Fungal infections like athlete’s foot.
Dry skin and hair loss on your toes and ankles.
Changes to the shape or size of your feet, like swelling, thicker toenails, or a condition called “rocker bottom,” which causes bones in the toes and feet to shift or break. Instead of a regular arch that curves upward, a “rocker-bottom foot” has a collapsed, rounded arch.
Left untreated, open sores can get infected. Because people with diabetic foot syndrome have a harder time fighting off infections, something as small as an ingrown toenail can turn into a major emergency without proper care.
Kidney and liver damage
Diabetic kidney disease, or diabetic nephropathy, affects about 1 in 3 Americans with diabetes. This condition makes it harder for the kidneys to process waste products and remove extra fluid.
If left untreated, diabetic kidney disease can turn into full kidney failure, which requires invasive treatments like dialysis, emergency surgery, or a kidney transplant.
Similarly, diabetes has close links to liver disease. Diabetes can create scarring on the liver, the organ responsible for filtering toxins out of our blood (like alcohol) and for creating and storing glucose in our bodies.
When this scarring builds up, it causes chronic liver disease (CLD) or cirrhosis, a liver injury that damages the liver’s filtering process. Left untreated, diabetic cirrhosis and CLD can cause:
* Liver cancer.
* Liver failure.
* Fat buildup in the liver, which leads to symptoms like fatigue, nausea, and jaundice.
Skin conditions
Nerve damage, blood vessel damage, and other symptoms of diabetes that affect the skin can cause:
Red, dry, irritated skin. People with diabetes sweat less, making it harder for the skin to stay cool and hydrated.
Dark patches of skin with a thick, velvety texture (_acanthosis nigricans_), often due to insulin resistance.
Diabetic blisters (_bullosis diabeticorum_), usually linked to nerve damage in the feet, legs, or hands.
Skin tags, small buildups on skin that usually look like large moles. Skin tags are usually harmless, but many people with diabetes choose to remove skin tags if they’re irritating or in an unsightly place.
Bacterial and fungal infections like athlete’s foot. Bacteria and fungus thrive on the excess glucose in a person’s blood, turning simple issues like yeast infections or ingrown hairs into wider-spread, potentially dangerous infections.
Cancer
Diabetes has been linked to an increased risk of cancers like:
Bladder cancer
Breast cancer
Colon cancer
Liver cancer
Pancreatic cancer
Sleep problems
Difficulties falling or staying asleep can be one of the most frustrating parts of having diabetes. As many as 50% of people with diabetes experience sleep problems like:
Insomnia, the inability to fall or stay asleep.
Obstructive sleep apnea, when someone stops breathing for a few seconds while sleeping, often many times in a single night. Sleep apnea can cause snoring, gasping, or brief moments of waking up that leave you exhausted in the morning.
Frequent trips to the bathroom overnight.
Night sweats, overheating and over-sweating while sleeping.
Nightmares or night terrors.
Restless leg syndrome, nerve damage that causes irritating sensations in the legs like tingling or numbness.
Feeling irritated, confused, or fatigued when waking up, no matter how much sleep you got.
What conditions can appear alongside gestational diabetes?
Gestational diabetes, or diabetes that develops during pregnancy, can cause serious problems for both the mother and the baby.
A pregnant person with gestational diabetes is at risk for:
High blood pressure.
Preeclampsia and eclampsia, potentially life-threatening conditions where blood pressure rises to dangerously high levels.
Developing type 2 diabetes later in life.
Needing a C-section delivery.
In addition, babies born to mothers with gestational diabetes are at a higher risk for:
An early (premature) birth.
Higher birth weight, which can cause birth complications like injuries.
Developing type 2 diabetes or obesity later in life.
Hypoglycemia, dangerously low blood sugar in newborns that can cause seizures.
Breathing difficulties like respiratory distress syndrome.
Stillbirth, a baby’s death just before or after delivery.
If I have diabetes, how can I lower my risk of developing other conditions?
Diabetes can be a serious health condition, but it can also be controlled with the proper diet, lifestyle changes, medication, and other treatments.
Here are a few of the best ways to lower your risk of developing a secondary condition due to diabetes:
Keep track of blood sugar and report any sudden changes to your doctor.
Make changes to your diet, ideally supervised by a doctor.
Get regular exercise. The standard recommendation is 30 minutes per day, at least five times per week.
Reach a healthy weight. Usually, this means losing weight, especially if you plan to become pregnant. Talk to your doctor or care team about the healthiest way to lose weight with diabetes.
Stop smoking.**
Improve your sleep—not just how much sleep you get, but the quality of it.
Reduce stress as much as you can.
Schedule (and attend!) more frequent check-ups and health screenings.
Take medications as instructed.
Create a trusted diabetes care team. Depending on your needs and symptoms, this care team might include:
Primary care physicians, family doctors, or pediatricians.
Certified diabetes educators.
Dieticians.
Nutritionists.
Personal trainers or other professional exercise coaches.
Weight loss coaches.
Where can I get more information about diabetes?
To learn more about diabetes, check out resources from organizations like:
You can also use Ability Central’s Service Locator tool to find nonprofits near you that offer support for people with diabetes.
Key Learnings
Type 1 and type 2 diabetes, especially when untreated or poorly managed, have been linked to multiple health problems and comorbid conditions.
These include issues with digestion, blood pressure, heart disease, uncontrolled weight changes, mental health, sleep, and damage to the nerves, kidneys, liver, eyes, feet, legs, and skin.
Gestational diabetes, which develops during pregnancy, can affect both the baby and the mother. The mother is at a higher risk for high blood pressure, pre-eclampsia or eclampsia, or needing a C-section birth.
Babies born to someone with gestational diabetes have a higher risk of premature birth, higher birth weight, hypoglycemia, breathing difficulties, or stillbirth.
When gestational diabetes interferes with pregnancy, both the mother and the baby are at a higher risk of developing type 2 diabetes later in life.
The best ways to avoid conditions that co-occur with diabetes are to manage your blood sugar, keep up with regular doctor’s appointments, make changes to your diet, get enough exercise, and improve your sleep quality.
