While having blood drawn might not be your favorite part of visiting your healthcare provider, blood tests are one of the best ways to gain insight into your overall health. This is because your blood holds clues to many aspects of the way your body is functioning.

It may be unclear when your doctor orders several types of blood tests. What do these tests mean? What will the lab technicians be looking for?

Understanding diagnostic testing helps you feel more in control of your health. Let’s take a look at the most common blood tests and find out precisely what they mean.

Complete Blood Count

During a Blood Draw

A complete blood count, or CBC, is one of the most common blood tests. Your doctor will likely order this test once a year as part of your annual physical.

Who Needs a Complete Blood Count?

A CBC test is your doctor’s best way to assess how your body is functioning. This is often the first blood test performed, which may lead to further testing if your doctor feels it’s necessary.

For instance, if you have unusual fatigue, fever, or bruising, your healthcare provider will order a CBC to help determine the cause of these symptoms.

What Does a Complete Blood Count Identify?

A complete blood count checks essential components of your blood. This test measures the number of red and white blood cells in your blood sample. The test also checks the number of platelets, which contribute to healthy blood clotting.

In addition, a CBC checks your hemoglobin, the part of the blood that carries oxygen, and your hematocrit, which measures the number of red blood cells against the amount of plasma in your blood.

What Do We Learn From a Complete Blood Count?

While a CBC test only looks at a few components of your blood, the test results reveal a lot of information. If your white blood cell count is high, this could indicate an infection. If your red blood cell count is low, your diet may lack certain nutrients.

A low hematocrit count can indicate more serious diseases like leukemia.

But low or high numbers on a CBC don’t always indicate a problem. For instance, people who live at high altitudes often have a low platelet count. It’s always best to ask your doctor to explain each aspect of the CBC test when the results come back.

Basic Metabolic Panel

The basic metabolic panel test is also known as Chem 7 or BMP. This blood test looks at seven components of your blood and delivers insight into how specific parts of your body function.

Who Needs a Basic Metabolic Panel?

Your doctor will order a basic metabolic panel before a surgical procedure to better understand possible complications. They might also request a Chem 7 if your doctor needs information that the CBC test did not provide.

What Does a Basic Metabolic Panel Identify?

The basic metabolic panel test isolates seven components present in your blood. These are blood urea nitrogen, glucose, carbon dioxide, serum potassium, serum chloride, serum sodium, and creatinine.

What Do We Learn From a Basic Metabolic Panel?

The seven substances tested with a basic metabolic panel give your doctor more information about organ function. For example, low or high blood glucose can indicate diabetes and other disorders related to blood sugar. Likewise, unusual carbon dioxide levels can indicate a problem with your lungs.

Cord Blood Banking

High blood urea nitrogen and creatinine levels may mean your kidneys aren’t functioning correctly. Lastly, your sodium, potassium, and chloride levels explain your heart function. These are the electrolytes that support many of your bodily functions.

Certain medications, dehydration, and menstrual cycles can affect the results of a basic metabolic panel. Therefore, your doctor must be aware of your medicines, lifestyle changes, and the date of your last menstrual period.

Comprehensive Metabolic Panel

A comprehensive metabolic panel blood test, also called a CMP or a Chem 14, is a more complete version of the basic metabolic panel. This test studies the seven blood components in the basic metabolic panel and the additional seven components not studied in the Chem 7 test.

Who Needs a Comprehensive Metabolic Panel?

Many people with chronic illnesses receive this test as it allows your doctor to study whether specific parts of the body are functioning correctly. Additionally, some medications can impact the way organs function, and this test helps your doctor decide if the medication’s benefits outweigh the risks.

Your doctor may also order a CMP over a BMP to be more thorough and proactive regarding your health.

What Does a Comprehensive Metabolic Panel Identify?

The CMP test measures 14 components in your blood. In addition to the seven studied in the basic metabolic panel, an additional seven are looked at in this test.

In the Chem 14 test, your doctor will look at your calcium, bilirubin, protein, albumin, alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase levels.

What Do We Learn From a Comprehensive Metabolic Panel?

One of the main reasons your doctor chooses this test is to check your liver function. Suppose you have a history of liver disease or alcohol use disorder. In that case, this test reveals how well your liver is removing toxins from your body and if further treatment is necessary.

A CMP test also helps determine how well your kidneys are handling their job. Since some medications affect liver and kidney function, your doctor needs to check periodically to be sure your liver and kidney levels are in a normal range.

Vitamins and supplements can affect the results of a CMP test, so it’s important to tell your doctor about everything you take regularly.

Blood Typing Test

Everyone has a specific blood type. Knowing your blood type is helpful. However, medical professionals need to know your blood type as this information is necessary, especially in an emergency.

Who Needs a Blood Type Test?

Sometimes, a doctor will add a blood type test order to other blood tests to save time. However, in most cases, a blood type test is given before major surgery. This ensures the surgical staff has the correct type ready to go if you need a blood transfusion.

Pregnant women are also routinely given different types of nutrition blood tests.

What Does a Blood Type Test Identify?

Each human has one of eight blood types. They’re labeled with letters and a positive or negative connotation. The blood groups are A, B, AB, and O.

Typing blood is essential, but it’s also a specialized test that reveals pertinent information. When a clinician performs a blood type test, they look for antibodies and antigens. Each blood type carries antigens and antibodies unique to its type.

What Do We Learn From Blood Type Tests?

In short, this test confirms your blood type. However, your specific blood type can affect how you receive medical care.

For instance, if you have type A blood, you have A antigens and B antibodies. If you receive type B blood, your antibodies will attack the foreign blood.

Type AB blood has both A and B antigens and no antibodies. A person with AB blood can receive all blood types. People with this blood type are known as universal recipients, meaning they can take any blood type.

blood tests

Type O blood doesn’t have type A or type B antigens. This means those with A, B, or AB blood can usually receive type O blood with little risk.

Another aspect of blood typing is the rhesus, or Rh, factor, indicating the presence or absence of a specific protein. This protein is present in people with positive blood and absent in negative blood. Having positive or negative blood generally only affects pregnant people.

If a pregnant person has a negative Rh factor and her fetus has a positive Rh factor, the mother’s blood could create antibodies that can attack the fetus’s positive blood type. Luckily, Rh screening is a routine part of prenatal care, and physicians can easily administer Rh immunoglobulin, preventing the parent’s antibodies from interfering with the fetus’s blood.

Sexually Transmitted Infection Tests

Regular STI blood tests can catch infections while they’re still easy to treat. Without regular STI screenings, these infections can spread to your partners and cause long-term damage to your health.

Who Needs a Sexually Transmitted Infection Test?

You should talk to a doctor about STI testing if you are:

  • Sexually active
  • Have multiple partners
  • Have unprotected sex

It can be an uncomfortable conversation but remember that your doctor focuses on your health, including your sexual health.

Additionally, people born between 1945 and 1965 are strongly encouraged to get tested for hepatitis C.

What Does a Sexually Transmitted Infection Test Look For?

An STI blood test screens for diseases like HIV, syphilis, hepatitis, gonorrhea, herpes, human papillomavirus, and chlamydia. Many people with an STI don’t display external symptoms, so a blood test is the best way to determine if you have one of these infections.

Many physicians don’t routinely order STI testing, so if you feel you might have been exposed, it’s important to share this information with your doctor.

What Do We Learn From Sexually Transmitted Infection Tests?

Again, early STI diagnosis is key to receiving treatment and preventing more serious medical problems. In addition, women are more at risk of complications from STIs than men.

Undiagnosed or untreated STIs can result in infertility in women, pelvic inflammatory disease, pregnancy complications, and certain cancers. Most STIs are bacterial and are treated with antibiotics. Viral STIs require different treatments and medicines, but many of them can be managed or have the possibility of a cure.

How to Prepare for All Types of Blood Tests

When your doctor orders blood tests, they often come with instructions for you. It’s essential to follow these instructions carefully. If you don’t, the test results may not be accurate.


Many blood tests require that you don’t eat or drink anything for several hours before your test. This is because when we eat and drink, the makeup of our blood changes. For example, sugars, proteins, and fats can change certain parts of the blood, which may give false results on blood sugar and lipid levels.

Most doctors allow sips of water to take regularly scheduled medications but ask your doctor beforehand.

Visiting the Lab

Your healthcare provider may be able to draw your blood for testing in their office. However, in most cases, you’ll need to visit a testing laboratory. Trained phlebotomists will draw your blood, and lab technicians will perform the ordered tests.

The results are then sent to your physician to analyze, after which they’ll generally call you with the results.

Some laboratories require appointments, so if you’re fasting, try to make the appointment first thing in the morning.

Laboratory Alternatives

For many people, scheduling a laboratory appointment is inconvenient. Work and family obligations often leave little time for appointments. Still, others may not feel comfortable in a crowded medical facility or have underlying conditions that leave them vulnerable to disease transmission.

Lack of transportation may also be a factor.

Common Blood Tests

An innovative way to avoid the lab is by utilizing mobile phlebotomy services. Trained phlebotomists can travel to your home or office to draw your blood at a time that’s convenient for you. The phlebotomists travel with all the necessary equipment and make your blood draw quick and easy.

In this post, you can learn more about mobile phlebotomy services.

Schedule Regular Blood Tests for Peace of Mind

Your doctor may order several types of blood tests throughout your life, and it’s essential to complete the tests promptly. It’s also important to follow any pre-test instructions your doctor might give you. Blood tests are one of the best ways to identify health issues early and prevent them from worsening.

For more health and wellness tips, check out our other articles and follow the Florida Independent to stay up to date.

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