Blood Work 101: What Lab Results Really Mean
Blood work is so confusing. What do all those numbers mean? How the heck do you even pronounce that word? What do the results say about overall health?
I know what I’m looking for when clients come to me with their lab work. I learned lab values in grad school and have used them in my practice for years. I indeed understand why they can be confusing, but you really should have a cheat sheet to refer to since, after all, the results tell you lots about what’s going inside of that bod of yours.
It’s back to school today friends. Now, keep reading! You don’t want to miss this lesson.
Blood Work 101: What’s the Deal?
Even with my training, looking at lab results can be confusing – they aren’t always straightforward to read and results can be put in different orders, depending on the lab. Sometimes the normal range is in front of the result and sometimes it is the other way around.
Unlike lab results, a lot of the work I do is incredibly subjective: “how much pasta do you think you ate?” and “do you remember what you had to drink with your dinner?” I kind of like the black and white and concrete evidence I get when I look at lab values.
I use blood pressure results when I teach my clients with high blood pressure how to be mindful of sodium in their diet — eliminating their salt shaker use, drinking enough water and managing their stress. Or I teach clients with high cholesterol how to watch the trans and saturated fat found in animal foods and processed foods.
Even if you brush off your lab results because your doc says you are in a “healthy range”, you should always ask for a copy of your blood work so you can compare it through the years. If you want to know what the digits mean, check this out.
You may not even be aware, but every time you go to the doctor’s office, the nurse checks out your pulse and blood pressure. Your blood pressure is the force of blood against the walls of your arteries. Hence, the word “pressure”.
It helps us look at two numbers, the systolic pressure (as the heart beats, it’s the number put on the top of the fraction) and the diastolic pressure (as the heart relaxes, the number on the bottom of the fraction). Blood pressure is written as systolic/diastolic pressure. For example, you may be told your blood pressure is 110/70.
- Optimal—120/80 or lower
- Prehypertension—120-139/80-89, (note: higher number equals more “pressure”)
- High—140/90 or greater
Hypertension is the same thing as high blood pressure; you have it if your blood pressure is 140/90 or higher. If you have high blood pressure, you are at greater risk for developing heart disease and stroke.
If you get a higher than normal number for the first time, rest and relax a few minutes and take your blood pressure again. Sometimes the stress alone of being at the doc can make your heart work overtime.
Basic Metabolic Panel
You’re going to get something called a basic metabolic panel at your annual checkup as well. It’s a blood draw that tells the physician: how your kidneys and liver are doing their jobs, how your blood sugar is doing, your cholesterol and calcium levels, and your electrolyte and protein levels.
Remember that you can’t eat for 8 hours before you get your blood work done or the results won’t be true! Just as a note, don’t freak out if the numbers I have below are slightly different than your lab’s normal range. What is “normal” from a laboratory can vary slightly from place to place.
- Albumin: 3.9 to 5.0 g/dL – this measures protein in your blood
- Alkaline phosphatase: 44 to 147 IU/L – this looks at your liver and nutrition status
- ALT (alanine aminotransferase): 8 to 37 IU/L – measures your liver functioning/status
- AST (aspartate aminotransferase): 10 to 34 IU/L – looks at kidney and liver status
- BUN (blood urea nitrogen): 7 to 20 mg/dL – indicators of heart and kidney functioning
- Calcium: 8.5 to 10.9 mg/dL – important for almost all organs in the body, can be a marker of many disease states, this is not measuring the calcium in your bones, but the calcium in your blood
- Chloride: 96 – 106 mmol/L – can measure poisoning and alkalosis/acidosis (how well your pH is regulated in the body)
- CO2 (carbon dioxide): 20 to 29 mmol/L – measurement of metabolic function and pH balance (how basic, neutral or acid our blood is)
- Creatinine: 0.8 to 1.4 mg/dL – marker of kidney functioning
- Glucose test: 100 mg/dL – diabetes marker and measure of insulin functioning
- Potassium: 3.7 to 5.2 mEq/L – may be high/low because of medications and affects many organs in the body
- Sodium: 136 to 144 mEq/L – measures hydration status, is a marker for many disease states and balances the pressure on your artery walls
- Total bilirubin: 0.2 to 1.9 mg/dL – liver functioning marker
- Total protein: 6.3 to 7.9 g/dL – measure of infection and kidney/liver diseases
You’ll also get your cholesterol panel taken: this test measures the different fats in your blood. You need some fat in your blood for your body and organs to work, but doctors are specifically looking at the good fat and bad fats to make sure there is a balance in the ratio.
Just to be clear, this isn’t a ratio of fats in your diet – your body makes cholesterol in your liver and that process is influenced by your genetics, age, lifestyle and other factors. Too much bad fats (LDL and triglycerides) in your blood will make your arteries hard and can be responsible for heart disease and stroke. The good cholesterol (HDL) are responsible for undoing some of the damage from the bad cholesterol and support your body’s health.
- Total cholesterol: <200mg/dL – measure your combined LDL & HDL
- LDL cholesterol: <100 mg/dL is optimal – your “bad” cholesterol
- HDL cholesterol: >40-59 mg/dL (>60 considered protective against heart disease) – your “good” cholesterol
- Triglyceride: <150 mg/dL – measures a different kind of fat in the blood
- Cholesterol ratio: Divide HDL cholesterol into your total cholesterol. So, if your total cholesterol is 200mg/dL and your HDL cholesterol is 50 mg/dL, your cholesterol ratio is 4-to-1. According to the American Heart Association, the goal is to keep your cholesterol ratio under 5-to-1. The optimal ratio is 3.5-to-1. A higher ratio indicates a higher risk of heart disease; a lower ratio indicates a lower risk.
Other Blood Work Values
People have been asking me about other blood work values that are often mentioned in the news. Here are the ones I’ve been asked about the most:
- C-reactive protein: also a blood test, this is a more specialized measurement for heart disease, c-reactive protein is a marker of inflammation (how your body is responding to stress or damage inside). It is being used as a predictor of heart disease.
You’re at low risk of developing cardiovascular disease if your hs-CRP level is lower than 1.0mg/L
You are at average risk of developing cardiovascular disease if your levels are between 1.0 and 3.0 mg/L
You are at high risk for cardiovascular disease if your hs-CRP level is higher than 3.0 mg/L
- Homocysteine: if a person has B12 or folate deficiency, or if someone has suffered a heart attack or stroke, often their doctor will order a homocysteine test. It’s also a marker for heart disease and can give a bigger picture to the usual blood pressure and basic metabolic panel. Normal levels are 4 – 14 µmol/L and elevated levels are connected to increased risk of heart disease and stroke.
- HbA1c/Glycosylated hemoglobin: normal <5.7%, pre diabetes 5.7-6.4%, 6.5% or higher means diabetes. This test measures your blood sugar over several weeks or months. If you have diabetes, your doctor will tell you how often you need a blood test to measure your levels. Ask for this test if you have a family history of diabetes.
So all this number crunching may have you snoozing at your desk but hopefully it will have you reaching for the phone to make an appointment with your doctor because…You need to know your numbers!
Ask your doctor to go over anything in your blood work that is outside of the normal range. Sometimes it takes a few months or years to know if your blood test results are trending in a certain way.
Double and triple check with your doctor when you start new meds to see if you need more frequent blood tests. Empower yourself by having a good relationship with your doc and keeping up with regular visits. It’s nice to see your hard work pay off with a ‘no news is good news’ report.