Try to get eight hours of sleep the night before your test
It’s better to avoid salty, fatty foods for at least 24 hours before your test, and two or three days would be even better.
Avoid exercise before a medical test can increase your heart rate and drop your potassium levels.
Don’t drink coffee or any caffeinated products for at least one hour before your test.
To keep blood sugar and blood pressure from increasing don’t eat for at least two hours before the test. Twelve hours of fasting is preferred, so try to schedule your exam in the morning so you can fast overnight.
Drink water two hours before your test, it helps to produce urine sample
Keep a list of any medications (prescription and OTC) you’re taking for the examiner to record.