Blood Tests Your Doctor May Order and What They Mean

Doctors love ordering blood tests. This is because they offer great information about how you are doing medically. They allow your doctor to track how you are doing overtime and guide them on how best to treat you. So, here are some blood tests your doctor may order.

Blood tests

Troponin

A normal troponin level is <0.030 ng/mL. This is a protein that is secreted by your heart when it is injured or damaged. So, when Troponin is elevated in your blood it may indicate heart injury. This can happen if your oxygen levels are too low. It may cause ischemia or low oxygen to your heart and may also happen during heart attacks.²

Creatinine Kinase (CK)

This is an enzyme secreted by your heart when it is injured or damaged. So, an elevated CK may also indicate cardiac ischemia or a heart attack.²

CK-MB

It's a form of Creatine Kinase. It is also elevated when your heart is injured or damaged.²

Gamma GT

This test measures the amount of gamma-glutamyl transferase, an enzyme made by your liver, in your blood. It is secreted by your liver when it has been damaged. Many different health conditions may cause liver damage, including heart failure. Therefore, this is something your doctor may monitor.³

BNP

This is a B-type natriuretic peptide. It's a hormone made by your heart and secreted when your blood pressure changes. An elevated BNP may indicate different heart conditions, including heart failure.⁴

Blood Urea Nitrogen (BUN)

Heart failure may sometimes be linked with kidney failure. Urea is made by your liver but it is secreted from your blood by your kidneys. If your kidneys aren't working properly, your BUN may be elevated in your blood.

If your kidneys are not working, you may not be peeing enough. When this happens, you may have excess fluid in your body. This can cause your heart to be overwhelmed, causing heart failure.^{1, 5-7}

Creatine

Creatine is a waste product when your body makes energy from food. Your kidneys have the job of removing it from your blood. When your kidneys aren't working properly, they may not do a good job of this. This can cause your blood creatine levels to increase. Since heart failure and kidney failure are so closely linked, your doctor may also monitor your creatine level.^8-9

Sodium

Sodium is a mineral and an electrolyte that helps regulate the amount of fluid in your body. Many different things can cause low sodium levels. One of them is the use of diuretics. These are medicines that make you pee and are often used to treat heart failure.

Kidney disease is another thing that may cause it. Your doctor may also want to keep you on a low sodium diet because too much sodium can cause your body to retain fluid. It can also increase your blood pressure. So, for these reasons, your doctor may closely monitor your blood sodium levels.^10-11

Potassium

Like sodium, potassium is a mineral and an electrolyte. It is important for muscle function. Considering your heart is a muscle, it's important for your doctor to monitor your potassium levels. If you have extra potassium in your blood, it is filtered from your blood by your kidneys. So, kidney failure may cause your potassium levels to rise.

High potassium levels (hyperkalemia) can be harmful to your heart. Also, diuretics may cause you to pee out too much potassium which can cause a low potassium level (hypokalemia). This in turn can cause fatigue, weakness, muscle cramps, and abnormal heart rhythms. So, your doctor will also want to closely monitor your potassium levels.^13-14

High-density lipoprotein cholesterol (HDL)

This is your good cholesterol. It helps transport cholesterol from your blood to your liver. It helps remove cholesterol from your body. People with high HDL have a lower risk of heart disease and strokes.¹⁵

Low-density lipoprotein cholesterol. (LDL)

This is your bad cholesterol and high levels increase your risk of heart disease. Too much of this can cause the buildup of plaque in your blood vessels which can increase your blood pressure. It can also increase your risk of heart attacks and strokes.¹⁵

Prothrombin time (pro-time)

Prothrombin is a substance made by your liver. It helps your blood to form clots. Of course, blood clotting is helpful if you are bleeding. If you cut your finger, your blood clots which helps stop the bleeding. Blood thinners (like Aspirin, Lasix, and Bumex) are sometimes used to prevent clotting in your arteries. This is needed to prevent heart attacks and strokes.

Prothrombin time shows how fast it takes for your blood to form clots. If you are on blood thinners it will be purposely a little bit slower than normal. So, your doctor will want to monitor this level to see how well your treatment is working.¹⁶

INR

This is an acronym for International Normalized Ratio. It's another level that helps determine how fast your blood clots. It's also helpful to help determine how well your treatment is working.¹⁷

More things to know

These are just some of the blood levels your doctor may order. They may also want to monitor other blood levels. For instance, white blood cells (like neutrophils) may be elevated if you have an infection. A high glucose level may indicate that you have diabetes. Either way, your doctor can learn a lot about your health simply by ordering blood tests.

Some doctors will order blood tests on an annual basis. If you are sick your doctor may order them more frequently.

What about you? How often does your doctor order blood testing for you? Let us know in the comments below.