Complications of Type 2 Diabetes & How to Prevent It

Medically Reviewed By: DR. ANUPAM GHOSE, MBBS, Diabetes Care & Education Specialist November 14, 2023

Last updated on October 4th, 2023

In the battle against type 2 diabetes, we find ourselves on the frontlines of a metabolic disorder that impacts millions across the globe. This condition is characterized by a stubborn resistance to insulin and a relentless surge in blood sugar levels. But along with high blood sugar, there are also other complications of type 2 diabetes. Diabetes-related health complications are rising with diabetes. According to a World Health Organisation survey of  2019, there were around 20 lakh deaths alone due to diabetic complications that year. In this article, we’ll venture deep into all the categories of diabetes mellitus type 2 complications, exploring their lurking dangers and emphasizing the urgent need for proactive management to safeguard your well-being. Buckle up because the journey through type 2 diabetes mellitus without complications is not possible. Know them all in every type so that you don’t tackle them, or if you do, you do it with full knowledge.

Microvascular Complications of Diabetes Mellitus

Microvascular Complication of diabetes Mellitus

Talking of diabetes microvascular complications, there are mainly 3 complications you might face. These type 2 DM complications are injurious to smaller vessels in your body. Below are major microvascular complications of diabetes mellitus:

Diabetic Retinopathy

Diabetic retinopathy is one of the most commonly occurring diabetes microvascular complications. Diabetic retinopathy, as the name suggests, causes damage to the eye retina. This type 2 complication is the reason for thousands of blindness cases in diabetics worldwide. The risk of getting diabetic retinopathy depends solely on the level of hyperglycemia one has and its duration. Constantly having very high blood sugar over long periods increases the risk of diabetic retinopathy and other diabetes mellitus type 2 complications. In the U.K. Prospective Diabetes Study, hypertension, along with high blood sugar, was considered a prominent factor in developing diabetic retinopathy. The study also found diabetic retinopathy is more common in type 1 diabetics than in type 2 patients. However, the risk still can’t be neglected.

The worrying factor about diabetic retinopathy is that it may start to develop 7 years before diagnosis of type 2 diabetes. An enzyme called Aldose reductase is involved in the development of t2dm complications. In the intracellular polyol pathway, where glucose gets converted into glucose alcohol (sorbitol), the influx of sugar molecules increases when you have high blood sugar. This causes sorbitol accumulation, which causes osmotic stress and leads to the development of diabetic retinopathy over time. Another reason considered for the development of type II diabetes complications is glycoproteins. Glycoproteins are formed as a result of high blood glucose levels.

Oxidative stress is considered another reason. High blood sugar increases free radicals and the formation of reactive oxygens. Diabetic retinopathy development is classified as proliferative and background retinopathy. In proliferative retinopathy, vitreous hemorrhage occurs as new blood vessels are formed on the retinal surface. In background retinopathy, dot hemorrhages occur in the mid-players of the retina. Both cases are very harmful to the eye and can lead to permanent vision loss. Therefore, consult an experienced doctor or diabetologist for immediate prognosis and treatment.

Read More: Connections Between Diabetes and Hypertension.

Diabetic Nephropathy

Diabetic nephropathy is next among microvascular complications of diabetes mellitus. Poorly controlled or unregulated diabetes may lead to kidney damage. The blood vessel clusters are bruised, leading to problems in normal kidney functioning and causing high BP (blood pressure). In diabetic nephropathy, there is a deposition of microalbuminuria in the kidneys. Microalbuminuria is when there is 30 mg/d to 300 mg/d albumin in urine per 24 hours. This state then progresses to proteinuria, where albumin in urine becomes more than 500 mg per 24 hours. Around 10% of diabetes patients already have microalbuminuria at the time when their diabetes is diagnosed.

According to the Diabetes Prospective Complication study, type 2 diabetes and complications always progress fast. As a sample of type 2 diabetes, a microalbuminuria count of 2% at the time of diagnosis increased to 25% in 10 years. Kidney membranes become thick, and there is microaneurysm and nodule formation. The key to avoiding diabetic nephropathy is prevention, like other diabetes microvascular complications. Moreover, there is a sharp connection between HbA1c levels and diabetic nephropathy. High sugar levels for extended periods greatly damage kidneys and often lead to complete failure, forcing diabetics to opt for dialysis.

The gist of preventing any complications of DM type 2, including diabetic nephropathy, is keeping blood sugar levels in control. Other means of treatment also include using antihypertensive drugs, ACE inhibitors and ARBs (Antiotension receptor blockers). Hypertension is also considered a contributing factor therefore, exercise hypertension control. However, these drugs suggested above do prevent kidney damage, but following a healthy lifestyle will always sail above them. And opt for these drugs strictly on the prescription of your doctor, as these have severe side effects.

Read More: Can Type 2 Diabetes be Reversed Permanently?

Diabetic Neuropathy

The last of the microvascular complications of diabetes mellitus is diabetic neuropathy. In this, complications of DM type 2 peripheral nerve dysfunction happen in diabetic patients. Like other complications of t2dm, this too happens due to high blood glucose for a significant period. The nerve dysfunctions are proportional to the magnitude and time of hyperglycemia. Some diabetics may be prone to it due to genetic history. The exact damages to peripheral nerves are still under research. But damages are related to polyol accumulation, AGEs injuries, and oxidative stress. The majority of the foot ulcers occurring in diabetics are due to diabetic neuropathy.

In these complications of t2dm diabetes, patients commonly feel burning and tingling pain and numbness. Some patients may get painless foot ulcers. Therefore, it’s important to realize that a lack of symptoms doesn’t mean you don’t have diabetic neuropathy. Diagnosis of diabetic neuropathy includes a physical examination of the sensory response to touch, vibration, and temperature. An abnormal response in any one of the tests has more than an 87% chance of detecting this complication. Pure sensory neuropathy is the worst form of neuropathy. And gives diabetic patients sleepless nights due to its spread.

Neurological dysfunction can happen in any of your organs. This can cause any of the symptoms like diarrhea, constipation, erectile dysfunction, anhidrosis, silent ischemia and even sudden heart attack. That’s why diabetes patients are more prone to silent heart seizures. There is no particular treatment for diabetic neuropathy. The key is to prevent neuropathy just by improving glycemic control. And keeping blood sugar in the prescribed range.

Read More: Is Type 2 Diabetes Curable?

Macrovascular Complications of Diabetes Mellitus

Macrovascular Complication of diabetes mellitus

In diabetes mellitus macrovascular complications, big vascular arteries and veins get damaged. Chronic inflammation and damage occur in the arterial wall, causing atherosclerosis. Due to these damages, there is deposition of oxidized lipids of LDL cholesterol on endothelial arterial walls. Then monocytes attack the arterial wall, forming foam cells. Resulting in acute vascular infarction in which tissue starts dying due to inadequate blood supply.

Along with this, diabetics may also witness increased platelet adhesion and hypercoagulability. There is also platelet aggregation, in which free radicals develop in platelets and release nitric oxide. The coagulation and impaired fibrinolysis cause fatal heart attacks in diabetics. The top macrovascular complications in diabetics are:

  • Heart attacks (often silent ones)
  • Stroke
  • Paralysis attack
  • Peripheral vascular diseases

Studying type 2 diabetes with complications, it is found that heart problems are the top reasons for death due to complications for type 2 diabetes.

Framingham’s study says myocardial infarction in diabetics is higher than in non-diabetics with a genetic history of myocardial infarction. Therefore, now, top doctors and institutes like the American Diabetes Association consider artery disease as a prominent risk rather than a small risk factor.

Cardiovascular complications for diabetes type 2 patients also happen due to hypertension, obesity, sedentary lifestyle, hyperlipidemia, and increased coagulation. Irrespective of these factors, type 2 diabetes itself is an independent risk of having heart ailments. The presence of macrovascular complications of diabetes mellitus is also a precedent for strokes and coronary diseases. So, when dealing with diabetes mellitus macrovascular complications, demands an aggressive treatment of these conditions. Blood pressure regulation also helps decrease the risks. Next is the control of hypertension and the use of required drugs like ACE inhibitors and ARBs. However, remember to use them only on a prescription by your diabetologist.

Read More: What Is Type 2 Diabetes Management?

Short Term Complications of Diabetes Mellitus

The macrovascular and microvascular complications of diabetes can further be categorized into short term and long term on the basis of their progression. Short term complications of diabetes mellitus happen when blood sugar goes very low or very high. Short term chronic complications of diabetes mellitus need to be addressed quickly to avert escalation.

There are various short term metabolic complications of diabetes mellitus:


Hypoglycemia is one of the secondary complications of diabetes mellitus. In this condition, the blood sugar goes very low. A non-diabetic has fasting sugar between 70 to 99 mg/dL and postprandial blood glucose below 140 mg/dL. In hypoglycemia, both fasting and postprandial levels fall below the minimum range. Symptoms of hypoglycemia include

  • Excessive sweating
  • Nervousness
  • Increased heartbeat
  • Unnatural hunger
  • Confusion
  • Irritation
  • Weakness
  • Unconsciousness

It’s important to treat hypoglycemia immediately to stop blood glucose from falling further. Your doctor will prescribe some effective medication and may advise external glucose drip.

Read More: Key Differences Between Diabetologists And Endocrinologists?


Hyperglycemia is another acute complication of diabetes mellitus type 2. Eating more sugar or carbohydrates than your body can handle for prolonged periods may lead to hyperglycemia. In hyperglycemia, blood glucose levels become ultra-high. Fasting blood sugar in hyperglycemia is greater than 125 mg/dL, and postprandial blood sugar is more than 180 mg/dL. This happens due to very little insulin in your body or increased insulin resistance. Both fasting and postprandial blood glucose shoot up. Symptoms of hyperglycemia include:

  • Thirst
  • Increased urination
  • Blurred vision
  • Tiredness
  • Frequent urination
  • Dry mouth
  • Recurring infections
  • Increase in sugar content in the urine

Read More: 10 Best Glucometers in India

Diabetic Ketoacidosis

Diabetic Ketoacidosis is another short term complications of type 2 diabetes. It is a dangerous, life-threatening condition. It is the case where the body does not produce the required amount of insulin. Here, the body starts converting fats to get energy. It may be beneficial for weight loss, but then it results in ketone formation. The body tries to get rid of them as it is a waste product with excess urine. The extreme levels of ketones cannot be removed, and they enter the bloodstream, thus resulting in the ailment. Symptoms of diabetic ketoacidosis include:

  • Short breath
  • Extremely dry mouth
  • Fruity-smelling breath

If your breath smells differently, then there is a high chance of ketoacidosis. And you need to visit the doctor for the same.

Hyperglycemic Hyperosmolar Non-Ketotic Syndrome (HHNS)

HHNS or Hyperglycemic Hyperosmolar Nonketotic Syndrome is among the list out complications of diabetes mellitus. Although rare, this diabetes complication is very dangerous. In HHNS, blood sugar levels become very high and negligence in treatment can even result in death. In these types of diabetes mellitus type 2 with complications occurs in sick and elderly diabetic patients. The blood glucose level starts to rise, eventually forcing the body to rinse out excessive sugar through urination. The frequency of urination increases, dehydrates the body and makes the patients very thirsty and weak.

As the body is sick and elderly, the body’s metabolism is slow and can not bounce back instantly. Delay in rehydration, and the blood glucose is still rising. In some time, the blood sugar becomes so high that the body goes into a coma. The only way to stop HHNS is by tracking the sugar levels when sick. Immediately connect with the doctor and constantly keep in touch with him/her.

Read More: How To Stimulate Your Pancreas to Produce Insulin Hormones in the Body?

Long Term Complications of Diabetes Mellitus

Long term type 2 diabetes complications develop over some period after diagnosis of type 2 diabetes. These type 2 DM complications are mainly how blood sugar negatively affects blood vessels. They are more or less the same diabetes complications microvascular macrovascular types. All the microvascular complications of diabetes mellitus are also considered long-term complications of diabetes mellitus.

Diabetes over long periods, if left to touch higher blood glucose, frequently inflicts damage on blood vessels. When blood vessels get damaged, the blood supply gets disrupted, causing many other problems. This may also lead to organ dysfunction. The long term type 2 diabetes complications cover majorly all the complications of diabetes, microvascular and macrovascular both. As the microvascular complications develop after damage to specific and smaller blood vessels, they are more organ-specific. Common diabetes microvascular complications include ailments like:

  • Diabetic Retinopathy (Eye related diseases)
  • Diabetic Nephropathy (Kidney damage)
  • Diabetic Neuropathy (Nerve damage)

All these have been explained above in the ‘Microvascular Complications of Diabetes Mellitus’ section.

In the long term complications of diabetes, high blood glucose damages larger blood vessels, too. Therefore, all the diabetes mellitus macrovascular complications will also come here. High blood sugar is very harmful and can cause all types of cardiovascular ailments like:

Read More: What is Glycemic Index And To Calculate?

Prevention of Complications of Diabetes Mellitus

Prevention of Complications of diabetes mellitus

  • Lifestyle changes, medications, and being proactive can help in controlling the long-term effects of diabetes or, in some cases, even reverse the case of diabetes.
  • Check your blood sugar level daily- it is highly recommended that you maintain your blood sugar levels as per the doctor’s instructions. Consulting a specialist, in this case, is mandatory as it can help in making informed decisions regarding the ailment.
  • Make dietary changes and include an exercise regime in your lifestyle- avoid sugar and high-fat food. It is mandatory to visit the doctor and maintain a healthy weight.
  • Avoid alcohol and smoking- alcohol and smoking can affect blood sugar levels and also conflict with the medicines thus, they need to be avoided.
  • Take care of mental health- not only physical health but even mental health is crucial. To stop or avoid the cravings for food that are off the list, it is mandatory to consult an expert.

Read More: HbA1c (Hemoglobin A1c) A1c Chart, Test, Levels, & Normal Range


In navigating the complex terrain of Type 2 diabetes, we’ve unravelled a multi-faceted tale of triumphs and tribulations. Our journey began with a look at the microvascular complications of diabetes mellitus, where small vessels bore the brunt of high sugar levels. We then zoomed out to examine diabetes macrovascular complications, highlighting the perilous link between diabetes and heart diseases. But this journey didn’t stop there. To eliminate all the misinformation, we also explained short-term and long-term complications of type 2 diabetes. All these complications show how uncontrolled diabetes can lay the foundation for devastating ailments. Knowledge is power, and understanding the complications of DM Type 2 and its potential consequences equips us with the tools needed for early intervention and vigilant management. Regular check-ups, blood sugar monitoring, a healthy lifestyle, and adherence to prescribed medications can be the swords and shields in this battle.

Read More: Chart For Normal Blood Sugar Levels for Adults with Diabetes


Are There any Side Effects of Low Blood Sugar Levels in Diabetes Type 2 Patients?

Just like the long-term effects, there are several short-term side effects or complications of t2dm. Hypoglycemia is the most common short-term side effect of type 2 diabetes. Blood sugar levels change throughout the day. If high blood sugar level is damaging then even low blood sugar is harmful. Symptoms of low blood sugar are as follows:

  1. Nausea
  2. Sweating
  3. Dizziness
  4. Headaches
  5. Tingling or numbness in feet or hands
  6. Anxiety, hunger, or weakness

In extreme cases it can result in fainting or seizures. If the blood sugar is too low then eat 15 grams of protein and wait for 15 minutes then check again if still low then repeat again. Once the blood sugar levels are normal then consume the normal nutritional meal.

Is it Important to Consult a Doctor Regularly?

Yes, going by the several types of research done in all parts of the world consulting a doctor regularly showed significant improvement in their blood sugar levels. In some cases, doctors were also able to list out complications of diabetes mellitus. Patients on diabetes medicines with constant doctor’s consultations were able to reduce the dose. Following what is recommended by a doctor can help to reverse diabetes. Thus assemble a health care team and visit them for regular check-ups. With the help of your physician, you can understand which experts you need to consult depending on the long-term risks that can affect you. It is only with regular check-ups, tests, and increased awareness that the risk for type 2 diabetes can be avoided. Even if you do not see any symptoms it is advised to connect with your doctor and understand the signs that you need to look at in your body.

What Foods Should be Completely Prohibited for Type 2 Diabetes Patients to Reduce the Long-term Effects of the Disease?

Sugar-loaded foods like soda, canned juices, sweets, and desserts are totally prohibited to avoid all types of complications of type two diabetes. These foods are also prohibited for people with heart issues or people who want to live a healthy life. Natural sweeteners like honey are also prohibited. Other foods that are prohibited include:

  1. Alcohol either sweetened or unsweetened is to be removed from diet
  2. Fatty foods like red meat, cheese, and butter should also be removed from the diet.
  3. Fried foods like chips, nuggets, and puris should not be consumed.
  4. Processed food like baked products, instant noodles, or instant meat should not be consumed.

What are Long Term Complications of Diabetes Mellitus?

The long term complications of diabetes mellitus include majorly all the macrovascular and microvascular complications of diabetes. They are:

  • Diabetic retinopathy
  • Diabetic neuropathy
  • Diabetic nephropathy
  • Cardiovascular ailments
  • Strokes
  • Peripheral vascular disorders

What are 4 Diabetes Mellitus Symptoms?

The type 2 DM complications have top symptoms like:

  • Frequent urination (Excessive)
  • Excessive thirst
  • Blurred vision
  • Tiredness
  • Frequent hunger
  • Sudden weight loss

However, do remember there is also type 2 diabetes without complications, so keep tracking blood sugar. Try not to keep it in the higher range. 

What are 4 Acute Complications of Diabetes Mellitus?

The top 4 acute complications of diabetes mellitus type 2 are:

  • Diabetic Ketoacidosis
  • Hyperglycemic Hyperosmolar Nonketotic Syndrome (HHNS)
  • Hypoglycemia
  • Hyperglycemia

These complications of DM type 2 are considered acute as they require immediate treatment and individuals with a history of particular complications are at an increased risk of progression.


What are the Six Complications of Diabetes Mellitus?

The top six complications of diabetes mellitus pdf are:


  • Diabetic retinopathy
  • Diabetic nephropathy 
  • Diabetic foot ulcers
  • Heart attacks and strokes
  • Diabetic neuropathy
  • Gum and mouth diseases

What are the major complications of diabetes mellitus?

There are mainly two types of major complications for diabetes type 2. They are macro and microvascular complications of diabetes. These are mainly long term complications of type 2 diabetes. In microvascular complications, we deal with damages and complications in the smaller blood vessels. In macrovascular diabetes, we talk of complications that happen in larger blood vessels. In short term complications, there are hypoglycemia and hyperglycemia, which both require immediate diagnosis and treatment.

Last Updated on by Dr. Damanjit Duggal 


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