Analyzing a simple blood sample can give you useful information about your health.

It’s a simple and fast process. It saves you money and helps stop serious diseases. You can order blood tests from trusted online sources for accurate results. A form will be sent to you. This form lets you go to a local clinic or lab to draw your blood. Then, your blood is tested, and you will get the results in just a few business days.

There are many helpful blood tests you can take to check your health and look for health issues. For instance, you can know if your blood sugar level is high, how your thyroid hormones are doing, or how much protein is in your blood. A lot of these types of tests need you to fast beforehand. This is something you should be aware of before having the test. Some common tests that may need fasting include the routine physical, blood glucose test, cholesterol test (lipid panel), triglyceride level test, serum iron test, vitamin B12 test, vitamin B complex test, renal function panel, and gamma-glutamyl transferase test.

Fasting for Blood Work: Why Is It Needed?

People need to fast before several blood tests. This is important because some foods and drinks can change the hormones in your blood. If you do not fast, the blood test results may not be correct. This can lead to the doctor making a wrong diagnosis.

If you eat something and then have a blood glucose test, your blood sugar levels could be very high. Based on your blood test results, the doctor might say that you have diabetes.

The body digests food and turns it into sugar called glucose. For the cells to take in this glucose, the pancreas releases insulin. A few hours later, the insulin helps the cells absorb the sugar from the blood. Your glucose levels will readjust to normal.

It is important to fast before certain blood tests. This helps the doctor find the usual hormone levels in your blood. If these levels are not normal when you are fasting, you might need treatment for your condition.

Fasting for Blood Work

What Tests Commonly Require Fasting?

At this moment, you might be asking, “What blood tests require fasting?" Not every blood test needs it, but some definitely do. Here are a few blood tests that require you to fast.

Not everyone needs to fast before a blood test. However, some blood tests may need you to fast. These tests usually include:

1. Blood Glucose Test

This test is very common and works as mentioned earlier. It helps the doctor find out the real sugar level in the body. Patients should not eat or drink anything except water for 9 to 10 hours before taking the test.

2. Cholesterol Test

Measuring cholesterol levels in the body is very important. It helps to find out different types of diseases, especially heart-related ones.

Cholesterol is a waxy substance that coats the inside of blood vessels. It helps keep the blood vessels flexible. But too much cholesterol can lead to blockages in veins and arteries. A clear sign of high cholesterol levels is high blood pressure.

Cholesterol has two main types: LDL and HDL. LDL cholesterol is often called the "bad" kind. High levels of LDL cholesterol can be harmful to your health.

HDL cholesterol is known as the "good" cholesterol. High levels of HDL are beneficial. A regular blood test can check your HDL and LDL cholesterol levels. With this information, your doctor can suggest changes, often about your diet and exercise plan.

3. Triglyceride Test

Triglycerides are a type of fat found in the human body. They act differently than cholesterol. Cholesterol helps build cells and is important for making hormones. In contrast, triglycerides are used for energy when the body needs it.

Each person uses calories every day. Calories from food or drinks that are not used turn into triglycerides. These are kept in fat cells. When the body needs more energy, it takes fat from these cells and changes the triglycerides back into energy.

Having too many triglycerides in the body can be harmful. They can thicken the walls of your arteries. This leads to high blood pressure and heart disease. Over time, very high levels of triglycerides can cause heart attacks and other heart problems.

4. Liver Test

Your liver does about 500 tasks in your body, based on some recent studies. Its main job is to clean your blood. It also helps with digestion and metabolism.

Fasting is needed before a liver function blood test. This helps stop food from affecting the blood hormones. A liver test can tell if there is any liver damage like liver disease. It checks if the liver makes the right hormones in the right amounts. It also shows how many B vitamins are stored in the liver. The test can find out if a patient has any kind of hepatitis too.

5. Metabolic Panel Test

A metabolic test checks various enzymes, electrolytes, and hormones in your body. It looks at substances like sodium, potassium, albumin (a protein), bilirubin, calcium, carbon dioxide, alanine transaminase, and others.

Keeping a balance of certain substances in your body is important. For example, too much sodium can make your blood acidic. This condition can lead to several diseases. Likewise, not having enough calcium can cause your bones to weaken. This can make you more likely to have fractures and osteoporosis.

You have to fast before a metabolic blood test. This is important because some foods have the substances that will be tested. If you eat or drink anything other than water before the test, it could change the results negatively. This might lead to a wrong diagnosis.

6. Kidneys Test

The kidneys are important organs in our body. They, like the liver, help filter out toxins and remove them. The kidneys have many functions. If they are hurt, they can even take on tasks from other organs.

A kidney blood test checks several important substances and hormones in the kidneys. One key part of this test is the glomerular filtration rate. This shows how well your kidneys filter out toxins. Before the test, you can only drink water. Eating or drinking anything else could overwork your kidneys.

7. Iron Blood Test

All people need a small amount of iron in their blood to stay healthy and feel energetic every day. A blood test can check how much iron is stored in your body. If you do not have enough iron, you may feel very tired and could develop anemia, which is a condition that causes extreme fatigue.

Iron is often in many different foods. Eating these foods before a blood test can raise your iron levels, which might give a wrong result. That’s why you need to fast for at least 8 to 10 hours before getting an iron blood test.

Keep in mind that some supplements you take, like multivitamins, may have iron in different amounts. You should stop taking these vitamins and minerals for at least 1-2 days before the test.

8. Vitamin B12 Test

Vitamin B12, which is also called cobalamin, helps with the metabolism of nearly all the cells in our body. You can find it in many foods and drinks. This makes it simple to get a good amount of vitamin B12 in one meal, especially if you enjoy eating vegetables and legumes.

This vitamin is very important for the nervous system. People who don’t get enough vitamin B12 and other B vitamins often get illnesses that affect their nervous system. If you need to have a vitamin B12 blood test, make sure not to eat or drink anything for at least 6 to 8 hours before the test.

9. Heavy Metals Panel

You can also test how many heavy metals are in your body. Some metals can harm your health if they are too high. For instance, arsenic, mercury, cadmium, and lead are common heavy metals found in people.

Some of these metals move through the blood, while others stick to bones and organs. If they are in high amounts, they can cause poisoning and, in severe cases, death. A blood test can help you find out how bad your heavy metal issue is. It can also show if you need treatment or detox.

You can't eat or drink before your blood test, especially if you are taking prescription medications. This is because some foods have heavy metals. Sardines can have high levels of arsenic, no matter where they come from. Other fish and seafood can have a lot of mercury too. It is best to fast for at least 8 to 10 hours before the heavy metal blood test.

10. Hormone Tests

Food can raise insulin levels in the blood. This rise can lower hormones like testosterone, IGF-1, thyroid, and more. If you are on TRT, fasting has no impact on your testosterone level, however.

Fasting for Blood Work Q&A - Answering Some of Your Questions

Now you know about fasting for blood work, you may still have some questions. Many people have questions about the type of test and fasting. It’s important to answer these questions. For example, what is fasting blood work? Why do you need it? How long should you fast before a blood test? This article will answer these questions and more about fasting for blood work.

1. Can I Drink Coffee, Alcohol, or Smoke During My Fasting for Blood Work?

No, you can't drink coffee, even black coffee, without sugar. Coffee has enzymes that can affect your liver and your hormone levels. You should avoid drinking coffee before a blood test.

Smoking is not allowed. It can harm your glucose levels and raise heavy metal levels in your body. The best choice is to quit smoking completely. This will make you feel much healthier.

You should not drink any alcoholic drinks if you are concerned about liver health and liver enzymes. This is important because alcohol can raise your glucose levels and cause inflammation in your body. It is best to avoid alcohol for at least 1-2 days before a blood test. This is because the body needs time to get rid of alcohol. You should also avoid smoking when fasting for blood work. Smoking can mess with your results, especially your hemoglobin levels.

2. Can I Chew Gum or Brush My Teeth Before the Test?

Chewing gum is not allowed. It affects how your body makes digestive fluids. The sweetness of the gum can also change your blood sugar level. Instead of chewing gum, you can brush your teeth, as long as you don’t swallow anything. If you swallow toothpaste, it may trigger hormones and enzymes in your body, so be careful with that.

3. Can I Exercise While I’m Fasting?

Ideally, no. This is true unless you are doing very light exercises that don’t use weights.

Exercising often raises the inflammation levels in your body. For instance, intense workouts like lifting weights or sprinting can increase C-reactive protein levels. This protein is a sign of inflammation. If you take an inflammation test while exercising, the results may not be correct.

Vigorous exercise can raise your testosterone and human growth hormone levels for a short time. If you take a blood test after working out, the results for these hormones may be wrong. This can lead to mistakes in the doctor’s diagnosis. Additionally, working out makes you feel hungry. However, if you are fasting, you can't eat anything. Not eating after exercising can make you feel dizzy and cause other issues. It's better to avoid the gym the day before your blood test.

4. For How Long Should I Fast?

As a general rule, the first thing you should do is fast for at least 8 hours of fasting before a blood test. Many doctors plan these tests for early in the morning. This way, you are asleep for most of the fasting time. Sometimes, you may need to fast for 10 or 12 hours, or even a longer period of time. Your doctor will tell you if this is necessary. You might also have to stop taking biotin supplements for 72 hours before a blood glucose test. For some tests, like a direct LDL cholesterol test, a longer fast of 14 hours may be needed. It is important to follow your doctor's advice about how long to fast before your specific blood test.

5. What If I Accidentally Ate Before a Fasting Blood Test?

It is common for patients, including pregnant people, to forget they are fasting and eat or drink something by mistake. If this happens, it's not a big deal, but you should tell your healthcare provider before the test. They will think about this when looking at the blood test results. In some rare cases, you might be able to change your blood test appointment if it has been a long time since you ate or drank. Remember, liquids like fruit juice, teas, and sodas should be avoided while fasting to get good test results, which is a good idea. After the blood test, feel free to enjoy your cup of coffee or have a snack!

6. Should I Take My Meds/Vitamins During My Fast?

As a basic guideline, the answer is no. This is because your medications and supplements may have ingredients that could change the hormones in your body. This means that the test results might be impacted, leading to an incorrect diagnosis.

Tell your doctor about the medications and vitamins you are taking. Ask if you should stop taking these while you fast. This way, you will know what to do.

7. What are Some Tips to Make Fasting for Blood Work Easier?

Fasting for blood work can be tough. Here are a few tips to help make it easier:

  • Plan your fasting time carefully: Schedule your blood work for early morning. This way, you can get a good night's sleep and reduce the time without food.
  • Stay hydrated: Drink a lot of water while you fast. But, avoid other drinks like coffee, tea, or juice. They could affect your blood test results.
  • Distract yourself: Keep busy during your fasting time. This can help you think less about food. Try reading, watching movies, or taking a walk.
  • Dress comfortably: Wear loose and comfy clothes to your blood work appointment. This will make you feel better during the test.
  • Talk to your healthcare provider: If fasting is hard for you or you have worries about it, let your healthcare provider know. They might give you helpful advice or adapt things to fit your needs.

Fasting before blood work is important. It helps make sure the test results are correct. You can follow these tips to make fasting easier. Stay positive, and you will get through it successfully.

Get Your Blood Test Today!

Did you know you can now buy fasting blood tests online? These are called direct-to-consumer labs. They are often affordable. You do not need to see a doctor or get a prescription. You will get your results in just a few business days.

Visit DiscountedLabs.com to see the popular blood tests available. Some of these tests may need you to fast beforehand. They will help you understand your health better.

References:

  1. Blood Tests - NHLBI
  2. Diabetes Testing - CDC
  3. Iron Tests - MedlinePlus
  4. Triglycerides Test - MedlinePlus
  5. Blood Glucose Test - MedlinePlus
  6. Fasting for a Blood Test - MedlinePlus
  7. Basic Metabolic Panel (BMP)—MedlinePlus
  8. Effect of dehydration on blood tests