2-hour oral glucose tolerance test

It can help identify gestational diabetes during pregnancy or another problem with glucose regulation. The testing service provides exact preparation instructions because eating, some medicines, and acute illness can affect the result.

Staff first take a fasting blood sample. You then drink a glucose solution and remain at the clinic while your body responds. A second sample is taken two hours later, and the laboratory reports the glucose values to the clinician who requested the test.

You may find the drink very sweet, and temporary nausea or light-headedness can occur. Moving around, eating, smoking, or drinking anything not permitted by the centre may change the conditions of the test.

Confirm when fasting begins and whether you may drink plain water. Tell the service about all medicines and supplements, and ask what to do if you are unwell. Continue prescribed medication unless the clinician or testing service gives different instructions.

Allow enough time to stay through the final blood draw. During the waiting period, follow staff guidance and report nausea, dizziness, sweating, or difficulty finishing the drink. Arrange a snack for afterwards if the centre permits it.

While at the clinic, tell staff immediately if you feel faint, become confused, vomit, or develop breathing difficulty. They can assess you and decide whether continuing the test is appropriate.

Outside the appointment, arrange medical advice if marked thirst, frequent urination, blurred vision, or persistent fatigue develops. Seek urgent care for fainting, confusion, repeated vomiting, severe weakness, or laboured breathing rather than waiting for test results.

Clarify why the test is being recommended, how pregnancy changes the interpretation, and when you will receive the values. Ask what each possible result would change, whether another test could be needed, and whom to contact if symptoms appear before the report arrives.