When you need to fast because you are supposed to have some lab tests, you might have to fast for up to 12 hours before having the test. Certain tests require fasting, such as cholesterol testing, glucose testing, etc. Ask your healthcare provider if you need to fast before having a certain test done. You should definitely stay away from alcohol for a full day before having your blood taken. Yet, for any unsure questions, just ask your doctor and you may be surprised at the answer.
Why Do I Need to Perform Fasting?
Before asking yourself, "can I drink water when fasting," let's first find out why you should fast before having certain blood tests done. Various substances contained in the beverages and foods you take enter into your blood, which can impact the results of certain blood tests. Usually, you will be required to fast before a blood glucose test. Similarly, you will need to fast before a lipid profile, which measures total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides. There may be other tests which require you to fast. If you fail to fast or don't fast the whole time required, the test results could be inaccurate. This will mean you will have to do the blood test all over again. If you don't think you will be able to fast, talk to your doctor before having the test.
Detailed Questions for Fasting
Below are some frequently asked questions regarding fasting. Continue to see if your wanted answers are covered.
1. Can I Drink Water When Fasting?
Yes, you can. It is perfectly okay to drink water when fasting. Actually, it is the only thing you can take into your body during the fasting period. Additionally,water intake can make you feel better during the fast and the blood drawing will be easier. Blood contains 50% water, so with enough fluid in your system, your veins will be more readily available and the lab tech will have an easier time taking out the blood.
Two related question:
- Can I drink juice? No, only water can be consumed during a fast.
- Can I drink coffee? No, you should not drink any kind of coffee or tea during the fasting period.
2. What Is the Duration of Fasting?
Before having blood sugar drawn or a lipid profile, your doctor will have you fast for as long as 8 hours. Yet, your doctor may have different instructions regarding fasting for you and you should follow the recommendations whenever possible.
You can have something to eat or drink as soon as the blood is drawn. So, it is best to bring a snack along with you. Also, it is a better idea that you appoint the blood test in the morning so that you will spend the most time of fasting while sleeping.
3. Should I Continue Medications When Fasting?
Usually, you need to continue the medications you have been taking when fasting, unless your doctor tells you not to. As for supplements like vitamins and minerals, you should your doctor's advice. Just don't mess up your medication schedule or forget to take an important medication during the fasting period.
4. More Facts You Should Know
There are several questions you may have besides "can I drink water when fasting?" These include the following:
- Can I chew some gum? No, you shouldn't even have sugarless gum as this can cause stimulation of the GI tract and can mess up the lab tests.
- May I exercise? No, exercising can alter the results of the testing.
- Can I smoke? No, smoking can adversely affect the results of the test.
What to Expect During the Procedure
After figuring out the answer to the questions like can I drink water when fasting, you will naturally want to know how the test is done. Below are some common procedures you may experience in your test.
Step 1: Confirm and Position You
First, you need to complete the paperwork which confirms that you have been fasting for the required time. Then the lab technician will take a look at your arm and hands to find a vein that is suitable for taking blood from. For any discomfort like faint, just inform the blood tester or collector, and s/he can talk you through your discomfort. You might decide that it is better to lie down for the test in order to avoid fainting or vomiting during the test.
Step 2: Get the Blood
When the lab technician has found a vein that is suitable to take blood from, he or she will take an alcohol swab and clean off the skin so that bacteria don't adversely affect the blood test. With needle and collection device being prepared, the technician will use a sterile needle to make a puncture hole into the skin and through the vein to get the blood sample.
Step 3: Label the Tubes
The lab technician will make use of different collection tubes in order to put various amounts of the collected blood in. The blood test may require just one tube of blood or several tubes of blood, depending on the test. All the tubes used to collect your blood will have a label put on them that identifies you by your name and your birth date.
Step 4: After the Blood Collection
When the blood has been taken out of your hand or arm and the needle has been extracted, you should put pressure with a cotton ball on the site in order to stop the bleeding from the vein. Then the cotton ball or some type of bandage will be placed over the site of blood collection. If you happen to be allergic to tape or to alcohol swabs, let the lab technician know prior to having the test done.
You shouldn't lift anything heavy or do any type of physical exercise for a day or so after the test, so that the area doesn't begin to bleed again or doesn't bruise.