Preparing correctly for your health checkup helps ensure accurate results and prevents tests from being delayed or canceled.
Most health checkup centers in Korea require fasting before blood tests, abdominal ultrasound, or endoscopy. However, instructions about water and medications may vary depending on the center and the tests included in your package.
This guide explains how to prepare for a health checkup in Korea.
When Should You Stop Eating?
Most checkup centers ask you to fast for approximately 8–12 hours before your appointment.
For a morning checkup, you will usually be instructed to stop eating at around 9 p.m. or 10 p.m. the night before.
During the fasting period, avoid:
- Food and snacks
- Coffee, tea, and juice
- Milk and other beverages
- Alcohol
- Candy and chewing gum
- Smoking
Always follow the instructions provided by your checkup center, as fasting requirements may differ depending on your scheduled tests.
Can You Drink Water?
Water instructions vary by checkup center.
Some centers do not allow water during the fasting period, especially when gastroscopy or abdominal ultrasound is included. Others may permit a small amount of plain water until several hours before the appointment.
Do not assume that water is allowed. Check the instructions sent by your screening center before your visit.
Coffee, tea, juice, milk, sports drinks, and flavored water should not be treated as substitutes for plain water.
What About Regular Medications?
If you take regular medications, contact the checkup center in advance to ask whether you should take them on the day of your appointment.
Do not stop prescription medication without first receiving appropriate instructions.
Blood Pressure Medication
Some centers may allow essential blood pressure medication with a small amount of water on the morning of the checkup.
Follow the instructions given by your checkup center.
Diabetes Medication and Insulin
Fasting while taking diabetes medication or insulin may increase the risk of low blood sugar.
If you take metformin, tell the checkup center before undergoing a contrast-enhanced CT scan, as you may need specific instructions depending on your kidney function.
Ask the checkup center or your treating doctor how to manage your medication before the appointment.
Anticoagulants and Antiplatelet Medication
Tell the center if you take blood-thinning medication, particularly if gastroscopy, colonoscopy, or a possible biopsy is planned.
Some medications may need to be adjusted beforehand, but the decision should be made after consulting the checkup center and the clinician who prescribed them.
What Should You Avoid the Day Before?
To help obtain more reliable results, avoid the following on the day before your checkup:
- Alcohol
- Heavy or late-night meals
- Excessive exercise
- Staying up unusually late
Try to eat a light evening meal and get adequate sleep.
Preparing for a Gastroscopy
If your package includes gastroscopy, fasting is required so that the stomach is empty during the examination.
Follow the center’s instructions carefully regarding food, water, and medications.
If you choose sedated gastroscopy, you may need someone to accompany you home. You should not drive, operate machinery, drink alcohol, or make important decisions for the rest of the day.
Preparing for a Colonoscopy
A colonoscopy requires more preparation than a standard health checkup.
You will usually receive separate instructions about:
- Foods to avoid before the examination
- When to begin a low-residue diet
- How and when to take the bowel preparation solution
- Which medications may need adjustment
Follow the bowel preparation instructions exactly. Inadequate preparation can make the examination less accurate and may require it to be repeated.
What Should Women Tell the Checkup Center?
Inform the center in advance if you:
- Are pregnant or may be pregnant
- Are breastfeeding
- Are currently menstruating
- Have an intrauterine device
- Have recently given birth
Pregnancy may affect whether certain examinations, particularly X-rays and CT scans, can be performed.
Menstruation can also affect urine tests, stool tests, and some gynecological examinations. The center may recommend postponing specific tests.
What to Bring
Bring the following items to your appointment:
- Passport or Residence Card
- Medication list
- Previous health checkup reports, if available
- Glasses or contact lenses
- Hearing aids, if used
- Stool sample, if requested in advance
You may also want to bring the appointment confirmation and any preparation instructions provided by the center.
On the Morning of Your Checkup
Before leaving for the center:
- Do not eat breakfast
- Follow the center’s instructions about water
- Take only medications you were instructed to take
- Do not smoke or chew gum
- Wear comfortable, easy-to-remove clothing
- Leave jewelry and valuables at home
- Arrive 10–15 minutes early
Tell the staff if you accidentally ate, drank, or took medication before the appointment. They will decide whether all scheduled tests can still be performed.
Quick Preparation Checklist
The Day Before
- Confirm your appointment time
- Review the center’s fasting instructions
- Ask about regular medications
- Avoid alcohol and excessive exercise
- Eat a light evening meal
- Begin fasting at the instructed time
The Morning of Your Checkup
- Do not eat
- Follow the instructions regarding water
- Take only approved medications
- Bring your identification and medication list
- Arrive early
Final Thoughts
Fasting instructions for health checkups in Korea are generally straightforward, but they are not identical at every hospital or screening center.
The tests included in your package, especially gastroscopy, abdominal ultrasound, colonoscopy, or sedated procedures, may affect how you should prepare.
Always follow the instructions provided by your checkup center and contact them in advance if you have questions about water, diabetes medication, blood pressure medication, anticoagulants, pregnancy, or other medical conditions.
Proper preparation helps you complete your examinations safely and obtain more accurate results.
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