Diabetes diagnosis process
When should you see a doctor?
Signs and symptoms for diabetes could point to a number of other conditions. If you experience one or more of the below, as a general rule, it is highly recommended that you see your physician:
- Feeling weak and / or sick to your stomach (nausea)
- Are very thirsty (even when drinking a lot of fluids) and urinating a lot on an ongoing basis
- Abdominal pain (a bad stomach ache)
- Find that you are breathing more deeply and faster than usual
- Have sweet breath (sometimes the smell can resemble nail polish remover) which can be a sign of very high ketones in the body
If you notice any other symptoms of diabetes, and especially if you are older than 45, it is highly recommended that you see your doctor and get tested. Early detection can help avoid serious complications and health problems.
Signs of serious trouble in any type of diabetes that will require immediate medical care include:
- Hyperglycemia (high blood sugar)
- Diabetic ketoacidosis (increased ketones in urine) - This is life-threatening
- Hyperglycemic hyperosmolar nonketotic syndrome (a sky-high blood sugar level that turns blood thick and syrupy)
- Hypoglycemia (low blood sugar)
Diagnosis and tests
Your doctor may use one of more tests to screen for diabetes if suspected during your consultation. He or she will follow recommended guidelines of screening tests to carefully make the correct diagnosis.
These guidelines include:
- Anyone with a body mass index (BMI) greater than 25, irrespective of age, and especially where additional risk factors are noted.
- Anyone 45 years of age and older.
Tests commonly done for diagnosis (type 1 and type 2 diabetes) are:
- Fasting blood sugar test: After an overnight fast, a blood sample will be taken. A level that is less than 100 mg/Dl is considered normal. If around the 6.1 – 6.9 mmol/L or 100 to 125 mg/Dl mark, it prediabetes will be diagnosed. If the level is 7.0 mmol/L or 126 mg/Dl or higher on two separate tests, a diabetes diagnosis will be made.
- A random blood sugar test: At a random time of day a blood test may be requested, irrespective of when you last ate. The random blood sugar level will be assessed and used to help make a diagnosis. A level of 200 milligrams per decilitre (mg/Dl), or 11.1 mmol/L (millimole) or higher will indicate diabetes.
- Oral glucose tolerance test: An individual will be requested to fast overnight, after which the blood sugar level will be measured. Then the person will be given a sugary liquid to drink, and the blood sugar levels measured again periodically for the following two hours by means of blood samples. After the two-hour period, a reading of more than 200 mg/Dl or 11.1mmol/L will indicate diabetes. A less than 140 mg/dL or 7.8mmol/L is considered normal, and anything in between 140 and 199 mg/Dl or 7.8-11mmol/L will fall into the prediabetes category.
- Urine sample tests: If your doctor suspects type 1 diabetes after any of the above blood tests are performed, a urine sample may be requested to check for the presence of ketones. A test for autoantibodies (harmful immune system cells) linked with type 1 diabetes may also be performed.
- Glycated haemoglobin test (A1C): A blood test that indicates a person’s average blood sugar level for the past 2 to 3 months. The average is measured as a percentage of blood sugar attached to haemoglobin (the oxygen-carrying protein in red blood cells). The higher the level, the more haemoglobin with sugar attached (an A1C level of 6.5% higher on two separate tests will indicate diabetes). A percentage level lower than 5.7 is considered normal. An in between level (around 5.7 and 6.4%) can indicate prediabetes.
Results may not be consistent and can be inaccurate. Common reasons for this may be that you are pregnant, or have other conditions such as a haemoglobin variant (an uncommon form of haemoglobin). If it is suspected that any other known conditions could cause inconsistencies, your doctor may not use this test to diagnose diabetes which he or she can foresee would render your results inaccurately. A diagnosis may not be made entirely based on this test. Your doctor may also screen for diabetes using any of the aforementioned tests as well
Should you be pregnant, your doctor will assess your risk, and the level of risk for gestational diabetes before recommending the below screening tests:
- Initial glucose challenge test: A women will be given a syrupy glucose solution to drink and after an hour blood will be taken to measure her blood sugar level. A normal level is usually below the 140 mg/dL mark (or 7mmol/L). A level higher than normal may only mean that you have an increased risk of gestational diabetes, and doesn’t necessarily confirm a diabetes diagnosis. The doctor will do a follow-up test to check for gestational diabetes if the level is higher than normal.
- Follow-up glucose tolerance test: An expectant mom will be requested to fast overnight. From there a blood sample will be taken and the fasting blood sugar level measured. She will be given another sweet solution to drink, which will have a higher glucose concentration. The blood sugar level will then be measured every hour for the next 3 hours. If it is found that at least two of the readings are higher than normal for each of the three ours o the test, gestational diabetes will be diagnosed.