Diabetes mellitus

Diabetes Mellitus

Diabetes is a condition where a person either does not produce required amounts of insulin or is unable to utilise insulin appropriately. It is a common (about 10% of the population), complex disease. It can cause complications if not treated and controlled well.

Types of Diabetes:

There are 2 common types of diabetes Type I and Type II. There are other rare varieties due to pancreatic diseases, hormonal disorders, in pregnancy, after drugs and even rarer genetic disorders.

Type I is the cause in about 10 % of cases, onset is in childhood or young age and insulin is required for treatment.

Type II is the common variety, onset is usually around 50 Yrs of age, often associated with overweight and the risk is high if one parent is diabetic (30 %) and if both parents are diabetic (50 %). During initial stages, diet modification and oral drugs may control sugars but later insulin may be required.


Classically symptoms in diabetes are polyuria (more urine), polydypsia (more thirst ) and polyphagia ( more eating). In children very high sugars may develop suddenly and patient may become unconscious at the onset (DKA etc). Infections both recurrent and difficult to treat may occur. However in a large no the disease remains without many symptoms and found out accidentally or when complecations arise.

Signs are seen only in advanced and long standing diseases. These are few and may include eye, heart, nerve changes, dehydration and very rapid breathing due to acid accumulation in the body.

Diagnosis of diabetes:

Diabetes is diagnosed by blood glucose testing or glycated hemoglobin levels.

Normal Plasma glucose level after 8 hrs of fasting is < 100 mg/dl. Normal 2 hrs after breakfast (called PP) or after 75 gms of glucose orally is <140 mg.   Diabetes is diagnosed if either fasting plasma glucose is >126 or PP or oral GTT (after 75 gms of glucose is >200 mg/dl.

If fasting value is 100 -125 it is called impaired fasting glucose and if PP or Oral GTT is between 140 and 199 mg/dl it is called impaired glucose tolerance( IGT).

In a person with symptoms of diabetes a random value of plasma sugar >200 mg /dl or fasing plasma sugar >126 mg/dl qualifies for diagnosis of diabetes.

Lab tests for diabetes  

For common types of diabetes the following tests may be required at the time of initial diagnosis.

Complete blood counts, Blood sugar, kidney and liver function tests, urine routine and urine for microalbumin, lipid profile, Chest X Ray, ECG. Ultrasonography of abdomen, fundus examination, foot examination and blood pressure is noted.

In Type I cases or where genetic, pancreatic or hormonal disorders are suspected, tests for these are carried out as appropriate.

This is a chronic disease and lifelong follow up and treatment are required.



Coming next ~

Complications of diabetes

Treatment of diabetes.