Misdiagnosis of Diabetes
The most likely diagnostic problem with diabetes is failure to diagnose it early because patients do not recognize its early mild symptoms. Once a doctor is seen, diabetes is not often completely misdiagnosed because it is well-known to physicians and has fairly definitive diagnostic tests (blood glucose test; urine glucose test). However, more difficulty is found in determining the correct type of diabetes, diagnosing any complications of diabetes, or associated diseases.
Undiagnosed Diabetes. The most likely misdiagnosis related to diabetes is that it remains undiagnosed in many people. This mostly refers to Type 2 Diabetes, where the disease can take years to progress to major symptoms, but undiagnosed Type 1 Diabetes can occur (though usually becomes visible within weeks or months). Read more about: Symptoms of Diabetes.
Acute Complications of Undiagnosed Diabetes: If diabetes is undiagnosed, some of the symptoms and complications can become very dangerous. These can often remain undiagnosed until too late, or can be misdiagnosed as something else. Fatality is possible. The complications include:
- Diabetic Ketoacidosis (DKA). This is a dangerous, potentially-fatal complications of diabetes, due to the production of acidic ketones in the blood. Suspected DKA is a medical emergency.
- HHNS. HHNS is similar to DKA, but has a slightly different profile due to the body still processing some sugars. It is mainly a complication of Type 2 Diabetes, whereas Type 1 Diabetes would usually lead to DKA. However, Type 2 Diabetes can also lead to DKA. HHNS should be treated as a medical emergency.
- Dehydration. The chronic urination symptoms of diabetes can often lead to dehydration, despite the patient having massive thirst and taking in lots of fluids.
- Electrolyte imbalance. The imbalance results from the onset of DKA or HHNS. Serious imbalance can have dangerous consequences, even a potential heart attack (e.g. from low magnesium) .
- Diabetic Coma
Most Dangerous Misdiagnosis: One of the most dangerous errors in diagnosis is to incorrectly diagnose a person with Type 2 Diabetes, sending them home with instructions about diet and how to monitor their blood sugar levels. If they actually have Type 1 Diabetes, insulin is required, and trying to treat it with diet changes alone is likely to result in DKA and even death.
There are real-world examples of this diagnostic mistake. A six-year-old girl died after being sent home in this way, with a Type 2 Diabetes diagnosis, and a diet treatment plan (insulin was required; DKA was the result).
But Type 2 Diabetes is extremely rare in children under 10; it’s almost certainly Type 1 Diabetes in that age group. And an older child or a teenager is actually the most likely age to get Type 1 Diabetes requiring insulin (although the reverse misdiagnosis is possible since some teens are being diagnosed correctly with Type 2 Diabetes).
Another example case is a 29-year-old man sent home with instructions about dieting and monitoring, with a diagnosis of Type 2 Diabetes. Although it’s more likely for a 29-year-old than a 6-year-old to have Type 2 Diabetes, the age is still an unusual age for Type 2 Diabetes. And at 29, the possibility of Type 1 Diabetes is still there, and this was the actual correct diagnosis (insulin was required).
Misdiagnosed: The list of conditions that mimic diabetes is not really that long. A total misdiagnosis is highly unlikely.
- Fructosuria. A rare condition that causes the appearance of fructose in the urine that may trigger a false positive on a urine glucose test. But a blood glucose test should not be high in this case.
- Xylulosuria. Another rare disease that causes some forms of sugar in the urine, but which also shouldn’t cause glucose in the blood.
- Renal glycosuria: This is where there is glycosuria due to a kidney disease (i.e. renal causes), where the kidneys are not properly filtering glucose out of the urine, but usually there is not also high blood sugars.
- Fanconi syndrome: May cause glycosuria (renal glycosuria) due to a kidney disorder, but will not have high blood glucose.
- Glucagonoma. A rare endocrine tumor of the endocrine pancreas, that over-produces glucagon, which can stimulate the liver to create too much sugar in the blood. (Note that the better known type of Pancreatic Cancer is not similar to this disorder; however, a pancreas disorder can sometimes lead to reduced insulin production and diabetes.)
- Diabetes Insipidus: Despite its similar name, this rare disease has almost no relationship to common diabetes, except that its hallmark symptom is excessive urination. This disease is a kidney disease (due to a pituitary disorder) and is extremely unlikely to be misdiagnosed as diabetes.
Hidden Causes (Secondary Diabetes): There are a number of medical conditions that can cause hyperglycemia, diabetes symptoms, or diabetes-like conditions, mainly due to their impact on the pancreas. These conditions may cause disorders that mimic either “insulin deficiency” or “insulin resistance”.
- Hyperthyroidism. An excess of thyroid hormone may sometimes cause diabetes-like conditions.
- Pancreatitis. An inflammation of the pancreas can sometimes cause the insulin-related part of the pancreas (endocrine pancreas) to fail, causing insulin deficiency. However, pancreatitis more commonly causes digestive symptoms than diabetes-like symptoms.
- Hemochromatosis (“bronze diabetes”). This disease causes insulin deficiency due to pancreas damage. A genetic disease that is often overlooked, occurring in about 1 in 200 to 300 people, which damages the pancreas, liver, heart, and joints, among other symptoms. If you are diagnosed with diabetes, then a second diagnosis of hidden hemochromatosis is one of those rare cases where it’s good to get a second disease! Hemochromatosis is often readily treatable, and doing so can often improve diabetes symptoms, or at least stall any further diabetes progression. (Read more about: Hemochromatosis.)
- Pancreas disorders. Other disorders of the pancreas can affect it in a way to cause diabetes-like symptoms. Pancreas injury of any type, or any pancreas surgery, may also cause insulin deficiency.
- Acromegaly. A rare and insidious disorder of the growth hormone that can cause a form of secondary diabetes.
- Gigantism. An overgrowth disorder in children, similar to acromegaly in adults.
- Cushing’s syndrome. Another endocrine disorder that can cause secondary diabetes. Cushing’s syndrome involves the adrenal glands producing too much corticosteroid hormones (hypercortisolism), so the effect is similar to “steroid diabetes”. There are usually various other symptoms.
- Pheochromocytoma. A form of adrenal gland cancer that may have secondary diabetes as one of its symptoms; other symptoms are likely.
- Somatostatinoma. An extremely rare form of cancer that may cause over-production of statins, and show the effects of secondary diabetes. Other gastrointestinal symptoms are typical.
- Glucagonoma (endocrine pancreatic tumor). Over-production of the glucagon hormone (due to a pancreatic tumor) stimulates the liver to continually output extra glucose into the bloodstream, resulting in hyperglycemia.
Drug-Related Diabetes: There are a number of drug medications that can sometimes cause diabetes or diabetes-like conditions.
- Down Syndrome
- Turner Syndrome
- Friedeich’s Ataxia
- Klinefelter Syndrome
- Glycogen Storage Disorder (Type 1)
- Laurence-Moon-Biedl Syndrome
- Refsum Syndrome
Wrong Type of Diabetes: Sometimes people are correctly diagnosed with diabetes, but the wrong subtype is diagnosed. There are two main types of diabetes and a few rare types.
- Type 1 Diabetes (Juvenile Diabetes). The insulin-requiring juvenile type of diabetes is less common, affecting about 0.5% of the population (about 1 in 200). A teenager diagnosed with diabetes would usually be considered for Type 1 Diabetes, but recent increases in teenage obesity rates have increased the rate at which teens are found to have Type 2 Diabetes. Read more about Misdiagnosis of Type 1 Diabetes.
- Type 2 Diabetes. The most common form of diabetes, which typically affects older adults in their 40’s or 50’s. However, some teens can get Type 2 Diabetes. A younger adult in their 20’s or 30’s could have Type 2 Diabetes, but Type 1 Diabetes may also be likely. It is rare for someone in their 40’s or 50’s or older to have Type 1 Diabetes, so misdiagnosis between the types in that age group is unlikely.
- MODY Diabetes. A rarer form of diabetes that is less well-known.
- Gestational Diabetes. A form of diabetes in pregnant women, that usually disappears after the baby is born. It is usually thought to be a form of Type 2 diabetes (or pre-diabetes) that is exacerbated by pregnancy’s hormone changes and weight gain, but becomes dormant again once these changes reverse after birth.
- Diabetes Insipidus. Not likely to be misdiagnosed! This is not actually a form of Diabetes Mellitus, they just have similar names for historical reasons. Diabetes Insipidus is a rare disease of the pituitary gland and the kidneys. It has nothing to do with sugars or the pancreas. The main similar symptom is excessive urine, which contains sugar in diabetes mellitus but is without sugar (insipid) in diabetes insipidus. A positive diabetic test for urine glucose or high blood glucose very quickly rules this one out.
- Pre-Diabetes. This is an early type of diabetes, also called Impaired Glucose Tolerance (IGT). It is often undiagnosed due to its mild or absent symptoms, but it is usually correctly diagnosed once diabetes testing is performed.
- Stress diabetes. This is a rare diagnosis. Acute stress can sometimes trigger a form of diabetes which, like gestational diabetes, is believed to be due to stress exacerbating an underlying condition of pre-diabetes or Type 2 diabetes. If stress is removed, this type of diabetes may reverse. Recurrence of pre-diabetes or Type 2 diabetes is common in later life.
Subtypes of Type 2 Diabetes: There are actually subtypes of the main Type 2 Diabetes, which can affect how to treat it. The main issue is whether your body is producing too much insulin but resisting it (called “insulin-resistant”), or the less common case where your body is producing too little insulin (called “insulin-deficient” type). Detection of insulin resistance (and hyperinsulinemia) makes it very likely that the diabetes is classic Type 2 Diabetes, but the detection of an insulin-deficient type may increase the suspicion of another rarer type of diabetes or secondary diabetes.
- Type 2 Diabetes Insulin-Resistant Type. This is the main form of Type 2 Diabetes, where the body cells fail to be able to properly process insulin. Most people with Type 2 Diabetes are “insulin resistant”, which means their body cells are resistance to insulin, and paradoxically, they often actually have levels of insulin in the blood that are too high.
- Type 2 Diabetes Insulin-Deficient Type. This refers to a form of Type 2 Diabetes where the pancreas produces less insulin than normal. Although Type 2 Diabetes is common, this subtype is not. Most people have the other type, the insulin-resistant type. However, a less common “insulin deficient” subtype of Type 2 Diabetes should not be overlooked. This subtype can often result from some form of hidden pancreas disorder (e.g. hemochromatosis, pancreatitis, pancreas injury, etc.)
- MODY Diabetes. A quite rare form of diabetes occurring in adults.
Undiagnosed Chronic Complications of Diabetes. The onset of Type 2 Diabetes can be so slow that the complications of diabetes can have time to develop prior to the diabetes being discovered. And once diagnosed, the careful watching for any signs of diabetes complications becomes an ongoing management concern. Read more about diabetes complications, but some of the complications more likely to be undiagnosed include:
- Diabetic heart disease. This is a serious concern, as diabetes-related heart disease is one of the main long-term killers of people with diabetes, although it usually only does so after years of struggling with diabetes control.
- Cerebrovascular disease (stroke). This refers to damage to the blood vessels in the brain. The risk is brain hemorrhage and stroke.
- Peripheral vascular disease
- Diabetic kidney disease. Like all forms of kidney disease, the early stages of this disorder can be without any major symptoms.
- Diabetic neuropathy. Damage to the nerves, which can cause a variety of different problems depending on which nerves are damaged.
- Diabetic peripheral neuropathy. Damage to the peripheral nerves (hands, feet, fingers, toes), which can cause issues like tingling fingers, tingling or numb toes, and various other concerns. Management of the feet in diabetics is of particular importance. Tingling toes is an extremely common symptom in diabetes.
- Mononeuropathies. Sometimes a single nerve may be affected by neuropathy.
- Diabetic gastroparesis. A paralysis of the stomach nerves causing digestive issues. This is a type of neuropathy.
- Diabetes diarrhea. A disorder of the intestines caused by diabetes. This is also a type of neuropathy.
- Diabetic retinopathy. Damage to the retina at the back of the eye, that can lead to vision loss.
- Autonomic neuropathy
- Diabetic foot ulcers.
- Erectile dysfunction (impotence). Diabetes is a major cause of erectile dysfunction.
- Stroke. People with diabetes have a high risk of stroke. This is a medical emergency.
- Chronic or recurring infections.
Associated (Comorbid) Conditions: Not only is there diabetes, and the various complications of diabetes, but people with diabetes can often have additional diseases. People with Type 1 Diabetes are more likely to have other types of Autoimmune Diseases (e.g. Addison’s Disease). A list of comorbid disorders for Type 1 diabetes includes:
People with Type 2 Diabetes often have three other disorders: hypertension, obesity, and high cholesterol, which is a cluster of four diseases (including diabetes) which is called Metabolic Syndrome (Syndrome X). There are various other associated diseases for diabetes. A list of these comorbid disorders for Type 2 diabetes includes:
- Metabolic syndrome (obesity; high cholesterol; hypertension; diabetes). Also known as “Syndrome X”.
- Insulin resistance
• • •
Back to: « Diabetes
Misdiagnosis of Diabetes
Can the A1C test result in a different diagnosis than the blood glucose tests?
Yes. In some people, a blood glucose test may indicate a diagnosis of diabetes while an A1C test does not. The reverse can also occur—an A1C test may indicate a diagnosis of diabetes even though a blood glucose test does not. Because of these variations in test results, health care providers repeat tests before making a diagnosis.
People with differing test results may be in an early stage of the disease, where blood glucose levels have not risen high enough to show on every test. Sometimes, making simple changes in lifestyle—losing a small amount of weight and increasing physical activity—can help people in this early stage reverse diabetes or delay its onset.
Source: NIDDK (NIH)1
Misdiagnosis of Diabetes
Are diabetes blood test results always accurate?
All laboratory test results can vary from day to day and from test to test. Results can vary
- within the person being tested. A person’s blood glucose levels normally move up and down depending on meals, exercise, sickness, and stress.
- between different tests. Each test measures blood glucose levels in a different way. For example, the FPG test measures glucose that is floating free in the blood after fasting and only shows the blood glucose level at the time of the test. Repeated blood glucose tests, such as self-monitoring several times a day with a home meter, can record the natural variations of blood glucose levels during the day. The A1C test represents the amount of glucose attached to hemoglobin, so it reflects an average of all the blood glucose levels a person may experience over 3 months. The A1C test will not show day-to-day changes.
Health care providers take these variations into account when considering test results and repeat laboratory tests for confirmation. Diabetes develops over time, so even with variations in test results, health care providers can tell when overall blood glucose levels are becoming too high.
Comparing test results from different laboratories can be misleading. People should consider requesting new laboratory tests when they change health care providers, or if their health care provider’s office changes the laboratory or clinic it uses for blood testing.
Source: NIDDK (NIH)2
• • •
Can the A1C test give false results?
Yes, for some people. The A1C test can be unreliable for diagnosing or monitoring diabetes in people with certain conditions that are known to interfere with the results. Interference should be suspected when A1C results seem very different from the results of a blood glucose test.
People of African, Mediterranean, or Southeast Asian descent, or people with family members with sickle cell anemia or a thalassemia are particularly at risk of interference. People in these groups may have a less common type of hemoglobin, known as a hemoglobin variant, that can interfere with some A1C tests. Most people with a hemoglobin variant have no symptoms and may not know that they carry this type of hemoglobin.
Not all of the A1C tests are unreliable for people with a hemoglobin variant. People with false results from one type of A1C test may need a different type of A1C test for measuring their average blood glucose level. The NGSP provides information for health care providers about which A1C tests are appropriate to use for specific hemoglobin variants at www.ngsp.org .
False A1C results may also occur in people with other problems that affect their blood or hemoglobin. For example, a falsely low A1C result can occur in people with
- heavy bleeding
A falsely elevated A1C result can occur in people who
- are very low in iron, for example, those with iron deficiency anemia
Other causes of false A1C results include
Source: NIDDK (NIH)3
• • •
Sometimes health care professionals are unsure if diabetes is type 1 or type 2. A rare type of diabetes that can occur in babies, called monogenic diabetes, can also be mistaken for type 1 diabetes. Treatment depends on the type of diabetes, so knowing which type you have is important.
Source: NIDDK (NIH)4
• • •
If genetic testing is not performed, people with monogenic diabetes may appear to have one of the polygenic forms of diabetes. When hyperglycemia is first detected in adulthood, type 2 is often diagnosed instead of monogenic diabetes.
Source: NIDDK (NIH)5
However, almost 25 percent of Americans with DM are undiagnosed, and another 57 million Americans have blood glucose levels that greatly increase their risk of developing DM in the next several years.3 Few people receive effective preventative care, which makes DM an immense and complex public health challenge.
Source: Healthy People (DHHS)6
• • •
About 7 million Americans today have diabetes but don’t realize it. This puts them at risk for the serious complications that can arise when diabetes is left untreated.
Source: NIH News in Health (NIH)7
• • •
More than 1 in 10 adults over age 20 has diabetes, but about 40% of them don’t know they have the disease, according to a large national survey.
Source: NIH News in Health (NIH)8
• • •
About 2.8% of U.S. adults, a third of those who have diabetes, don’t even know they have it.
Source: NIH News in Health (NIH)9
• • •
One of the key dangers of diabetes is that it often doesn’t display any symptoms at all, making it hard to diagnose until it’s severe.
Source: NICHD (NIH)10
• • •
One in four people with diabetes don’t know they have the disease.
Source: NHS Choices UK12
Undiagnosed Stats: Diabetes
Seven million of these people are undiagnosed.1
Source: NICHD (NIH)13
Related Misdiagnosis Issues
Complex diagnosis issues or misdiagnosis may occur with conditions such as:
- Pre-Diabetes Misdiagnosis
- Pregnancy Misdiagnosis
- Hemochromatosis Misdiagnosis
- Metabolic Syndrome Misdiagnosis
- Acromegaly Misdiagnosis
- Heart Attack Misdiagnosis
- Kidney Disorders Misdiagnosis
- Cancer Misdiagnosis
- Stress Diabetes Misdiagnosis
- Stroke Misdiagnosis
- Diabetic Gastroparesis Misdiagnosis
- Acne Misdiagnosis
- Dementia Misdiagnosis
- Heart Disease Misdiagnosis
- Depression Misdiagnosis
- Psychiatric Disorders Misdiagnosis
- Pneumonia Misdiagnosis
- Inflammatory disorders Misdiagnosis
- Asthma Misdiagnosis
- Lupus Misdiagnosis
- Pre-Diabetes: Undiagnosed Pre-Diabetes: The main issues with misdiagnosis of Pre-diabetes is that it remains undiagnosed in many people. Early
... More on Pre-Diabetes »
- Pregnancy: The management of pregnancy is a major medical issue and there are various diagnostic concerns. See your doctor for the
... More on Pregnancy »
- Hemochromatosis: Undiagnosed Hemochromatosis: Because of its slow and insidious onset, hemochromatosis can remain undiagnosed for years or decades. A person may
... More on Hemochromatosis »
- Metabolic Syndrome: Three of the four disorders in Metabolic Syndrome are inherently difficult to diagnose: hypertension, diabetes, and high cholesterol. All of
... More on Metabolic Syndrome »
- Acromegaly: Undiagnosed Acromegaly. Because of its insidious nature, acromegaly can often remain undiagnosed for some time. The patient is simply unaware
... More on Acromegaly »
- Heart Attack: A heart attack usually doesn’t stay undiagnosed for long. However, the early stages can be misdiagnosed as being other
... More on Heart Attack »
- Kidney Disorders: A number of different types of kidney disorders can fail to be diagnosed because there are no obvious symptoms. A
... More on Kidney Disorders »
- Cancer: Cancer is difficult to diagnose by its very nature. There are literally hundreds of types. Many types of tumors are
... More on Cancer »
- Stress Diabetes: Diabetes More Likely: Stress diabetes is an enticing diagnosis because it’s a reversible form of diabetes. A patient may
... More on Stress Diabetes »
- Stroke: The main concern with stroke is that it can be diagnosed too late. The symptoms are not that well-known
... More on Stroke »
• • •
- Source: NIDDK (NIH): niddk.nih.gov/ health-information/ diabetes/ overview/ tests-diagnosis/ a1c-test
- Source: NIDDK (NIH): niddk.nih.gov/ health-information/ diabetes/ overview/ tests-diagnosis
- Source: NIDDK (NIH): niddk.nih.gov/ health-information/ diabetes/ overview/ what-is-diabetes/ monogenic-neonatal-mellitus-mody
- Source: Healthy People (DHHS): healthypeople.gov/ 2020/ topics-objectives/ topic/ diabetes
- Source: NIH News in Health (NIH): newsinhealth.nih.gov/ issue/ apr2012/ capsule2
- Source: NIH News in Health (NIH): newsinhealth.nih.gov/ 2009/ March/ capsules.htm
- Source: NIH News in Health (NIH): newsinhealth.nih.gov/ 2006/ July/ docs/ 01features_02.htm
- Source: NICHD (NIH): nichd.nih.gov/ health/ topics/ diabetes/ conditioninfo/ Pages/ symptoms.aspx
- Source: NIDDK (NIH): niddk.nih.gov/ health-information/ diabetes
- Source: NHS Choices UK: nhs.uk/ conditions/ type-2-diabetes/ symptoms/
- Source: NICHD (NIH): nichd.nih.gov/ health/ topics/ diabetes/ conditioninfo/ Pages/ risk.aspx
• • •
Note: This site is for informational purposes only and is not medical advice. See your doctor or other qualified medical professional for all your medical needs.