Diabetes is a common disease that has three different types and causes symptoms like increased thirst, repeated urination, fatigue, etc. The complications are deadly and they are the main causes of death in diabetes. In this article, we will know everything about this deadly disease.


Overview of Diabetes

Diabetes mellitus commonly known as diabetes is a chronic metabolic disease. When blood glucose levels rise above the normal range, it is called diabetes mellitus.

It can happen either when the pancreas does not produce sufficient insulin or the body cannot effectively use the insulin. Insulin is a hormone that regulates blood sugar. In both instances, blood sugar will rise and this is termed as hyperglycemia.

In 2017 a total of 415 million people were suffering from diabetes. The figure is estimated to reach 642 million in 2040.

When blood glucose level is more than or equal to 7 mmol/L or 126mg/L in a fasting period and 11.1 mmol/L or 200mg/L, 2 hours after oral glucose challenge, then a person is diabetic.

There is a less severe hyperglycemic state which is termed as impaired glucose tolerance (IGT). The patient with IGT have the risk of complications and developing diabetes in the future, hence they also need treatment as like as a diabetic patient.

Types of diabetes

There are three types of diabetes

  1. Type 1 diabetes
  2. Type 2 diabetes
  3. Gestational diabetes
Type 1 Diabetes

Type 1 diabetes is an autoimmune condition. When the body produces an antibody against beta cells of the pancreas, it destroys insulin-secreting beta cells. The damaged beta cells cannot produce insulin and thus increases blood sugar.

Symptoms may appear suddenly. To treat type 1 diabetes, insulin must be administered from outside sources. For that reason, it was once called ‘Insulin-dependent Diabetes mellitus’ (IDDM) in the past.

Type 1 diabetes usually affects an early age. Hence it is used to called juvenile diabetes. It can severely damage tiny blood vessels of eyes, kidneys as well as nerves. It also increases the risk of heart disease and stroke.

Type 2 diabetes

The most common type of diabetes is type 2 diabetes mellitus. About 95% of adult diabetic patients are suffering from this disease. However, It is less severe than type 1.

Moreover, type 2 diabetes also causes destruction to the micro-vessels of eyes, kidneys and damage nerves. As a result, it increases the risk of heart disease and stroke.

In the case of type 2 diabetes, the body becomes resistant to insulin and in certain stages, the pancreas cannot secrete enough insulin to control blood sugar.

Type 2 diabetes progress day by day and needs medication either by direct insulin administration or taking oral hypoglycemic agents. Symptoms do not appear early and most of the cases, diagnosis occurs during other routine investigations.

Obesity, physical inactivity, and familial history are the most important predisposing factors for developing type 2 diabetes mellitus. Therefore, young people are increasingly diagnosed as diabetic, as obesity has become an epidemic in children nowadays. Fat can increase resistance to insulin.

Gestational diabetes

Diabetes that occurs during pregnancy is called gestational diabetes. Pregnancy can cause insulin resistance. It generally occurs during the mid or late stages of pregnancy.

Fortunately, these types of diabetes resolve after delivery of the baby. However, women with gestational diabetes are more prone to develop diabetes in the future. Around 10% of women develop type 2 diabetes later in their life.

The baby even faces a higher risk than the mother. Gestational diabetes causes abnormal weight gain to the unborn baby. It not only creates breathing difficulty during birth but also increases the rate of obesity and risk of diabetes later in the future.

The mother also needs a cesarean section more often due to a large baby. Damages to eyes, kidneys, and nerves also happen in this period. Therefore, treatment with supervision needs for gestational diabetes.

Symptoms of Diabetes

There are a wide variety of symptoms of diabetes. Symptoms of diabetes appear more or less in the same way in all three types of diabetes. The difference is in the time of appearance. The most common symptoms are underline below.

  • Thirst (dry mouth)
  • Polyuria (Frequent urination)
  • Nocturia (frequent urination at night)
  • Tiredness, fatigue, lethargy
  • Weight change (mostly weight loss)
  • Blurring of vision
  • Itching in the vulva
  • A predilection for sweet foods

Nausea, Headache, etc.

Causes of diabetes:

Type 1 diabetes: As I mentioned before, the reason behind type 1 diabetes is the autoimmune destruction of beta cells of the pancreas.

Some genes and environmental factors such as viruses, drugs, and chemicals influence this event. Few well-known viruses, for instance, mumps, Coxsackie B4, retroviruses, cytomegalovirus, Epstein-bar virus, etc. believed to be behind beta cells destruction.

Bovine serum albumin, which is a major constituent of cow’s milk, also associated with type 1 diabetes. An infant who is given cow’s milk early, are more likely to develop type 1 diabetes than those who were breastfed.

Type 2 diabetes: Overweight, physical inactivity family history are the main reasons for type 2 diabetes. Extra weight causes insulin resistance. The distribution of fat in the body also plays vital rules. Belly fat linked to more insulin resistance. Fat also responsible for various heart and blood vessels disease. However, regular physical exercise almost always prevents type 2 diabetes.

Gestational Diabetes: It is also related to insulin resistance. Hormones produced by the placenta have properties to insulin resistance. When the body cannot compensate resistance by secreting more insulin, then pregnant women become diabetic. Obese women even face more risk.

Some drugs that are responsible for diabetes:

  • Steroid (glucocorticoids)
  • Certain diuretics
  • Anti-seizure drugs
  • Niacin (a variant of vitamin B3)
  • Pentamidine

Some diseases which cause diabetes:

  • Pancreatitis
  • Cushing’s syndrome
  • Acromegaly
  • Hyperthyroidism  


The diagnosis of diabetes is based on confirmation of hyperglycemia, either by fasting blood glucose or random blood glucose, an oral glucose tolerance test (OGTT) or HbA1c.

Diabetes confirmed by:

  • Fasting plasma glucose more than or equal to 7 mmol/L or 126mg/dl
  • Random plasma glucose or 2 hours after a 75 g glucose load is more or equal to 11.1 mmol/L (200 mg/dl)
  • HbA1c more than 6.5% or 48 mmol/mol

There are prediabetic conditions that are termed as impaired fasting glucose and impaired glucose tolerance.

When plasma glucose is more or equals to 6.1 mmol/L (110 mg/dl) and less than 7 (126 mg/dl), it called impaired fasting glucose.

Impaired glucose tolerance is when fasting glucose is less than 7 mmol/L (126 mg/dl) and 2 hours after 75 g glucose oral drink is 7.8-11.1 mmol/L (140-200 mg/dl).


  • Urine glucose: It is a common procedure and done with dipsticks to detect diabetes.
  • Urine and blood ketone: Ketone in urine can be found in normal people with fasting for a long time and those who exercise or do strenuous work for a long period. Repeated vomiting and eating high fat and low carbohydrate diet also cause ketonuria. But, urine ketone along with glucose in urine indicates diabetes.
  • Urine protein: In the absence of urinary tract infection albumin in urine indicates kidney involvement and other macro-vascular diseases.
  • HbA1c: Very common investigation done by doctors to test the blood sugar level of the past 3 months
  • Serum creatinine: To test renal function
  • Fundoscopy: To see Retinal damage
  • ECG: Done to test the condition of the heart
  • Nerve conduction test to check neuropathy
  • Fasting lipid profile

Some other investigations may need according to the patient’s conditions.

Complications of Diabetes:

Diabetes has both acute and chronic complications. Uncontrolled diabetes can lead to some serious medical emergencies.

For example, Diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar state (HHS). Both occur if anyone does not properly control blood sugar. The patient needs immediate medical treatment. In the UK morbidity rate in DKA is 2%. The rate even higher in developing countries.

Another acute state in a diabetic patient is hypoglycemia. When blood glucose level goes down below 3.9 mmol/L it is called hypoglycemia. Normal people also may develop hypoglycemia but a diabetic patient with hypoglycemia may develop coma, even death if immediate initiatives not taken. Giving sweet food or drink can dramatically improve the condition.

In the long run, diabetes causes nephropathy, retinopathy, and neuropathy as well as heart and vascular diseases, even though blood sugar was controlled.

The most common consequence of diabetes is Myocardial infarction or heart attack. Ulceration of foot is very common among diabetic patients, which eventually may lead to amputation. For that reason, diabetes needs to be well controlled.

Management of Diabetes:

Diabetes is not a curable disease. However, it needs to be controlled to maintain day to day life. The aim of treatment is to prevent or minimize long term complications. Management of diabetes sometimes termed as 3D. Diet, discipline, and drugs.

Diet: This is a very important element in treating a diabetic patient. Between 80-90% type, 2 diabetic patients are overweight. According to the UK government Food Standards Agency, the number of carbohydrates should not exceed 50% of total energy intake.

The end product of carbohydrate is glucose. So it is impossible to control diabetes without controlling carbohydrate intake. Patients also need to avoid table sugar or honey. They also recommend that the total fat intake should not be more than 35%, of which polyunsaturated fat should be less than 11%. More about diabetic diet

Exercise: All patients with diabetes should be encouraged to do some form of physical activity. These include walking, swimming, cycling or gardening.

The American Diabetes Association suggest that adult over 18 years of age should do either 150 minutes per week of moderate-intensity exercise or 75 minutes per week vigorous exercise. People with disabilities should also follow the guideline to do some form of exercise.

Drugs or Medication: Type 1 diabetes always needs insulin administration with regular followup.

In type 2 diabetes doctors may at first advise the patient to change lifestyle. Many believe that along with lifestyle modification, the medication should be prescribed because most of the patients cannot maintain food restriction and physical activities.

Type 2 and gestational diabetes can be controlled by various oral anti-diabetic medicine. Insulin may be needed if the target sugar levels cannot be reached.


Diabetes mellitus is a major health-care concern around the world. In 2015 alone, globally, 5 million people died due to diabetes. Furthermore, the financial burden for this disease was 673 billion dollars, 12% of total health-care expenditure. So we should spend more time to get rid of this disease.


Davidson’ principles and practice of Medicine, 23rd edition

Harrison’s principles of internal medicine, 20th edition

Categories: disease

Dr Mazharul Islam

Dr. Mazharul Islam acquired a Bachelor of Medicine and Bachelor of Surgery from Sylhet MAG Osmany Medical College and trained in internal medicine at Dhaka Medical College, Bangladesh. He is a practicing and motivated Medical doctor. He is exclusively working to eliminate superstitious belief from the society


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