Health Literacy Section 203, What's Normal?

The BMI scale is crazy!  30 = obese?...Really???  Is there any legitimacy to it?

It all depends.  Everything must be first placed into context, and that context is your physical build and what is going on inside – blood pressure, kidney function, cholesterol, etc.  Despite the traditional interpretation of the BMI (body mass index) scale, a BMI of 25 to 29.9 is not bad if (and that is a big IF) the items listed above are pristine.  If your BMI is below 18 or is significantly above 30, you should check with your doctor to make sure that the risk factors that come along with being under or overweight are minimized.

What should my blood pressure be?

Normal blood pressure is 120/80 or below.  However, patients are generally not considered hypertensive, or as having high blood pressure, unless their numbers are consistently over 140 at the top OR over 90 at the bottom.  For patients with diabetes and other chronic diseases, that upper threshold is usually lowered.  It is not uncommon for smaller and/or younger persons to have blood pressures that are below 100 at the top and 70 at the bottom.  As long is this consistent and there are no symptoms of dizziness, light-headedness, or chest pain, there is no concern.

A normal resting pulse (heart rate) ranges from 60 to the high 90s.  It is not uncommon for athletes to have a slightly lower pulse at rest.

What’s normal cholesterol?

Allow me to put an end to people walking around talking about their total cholesterol levels: stop it.  While total cholesterol is indeed “technically” used as a screen for further cholesterol testing, your cholesterol is interpreted by your physician in the context of your LDL cholesterol (the bad cholesterol).  That’s the number you should know.

Now here’s the tricky part.  All LDL cholesterol is not created equal, meaning this:  The LDL cholesterol is evaluated based on 5 cardiovascular risk factors – age, high blood pressure, smoking history, history of early heart issues in a primary family member, and low HDL cholesterol (the good kind).  Normal LDL cholesterol should be in the 70-100 range or lower.  However, if it is deemed that you have 0-1 of the risk factors above then you are technically off the hook for treatment.  This threshold lowers to 130 for those with 2 or more risk factors and to 100 for those with certain chronic diseases.  Please note that some conditions, such as diabetes, require that your cholesterol be treated no matter what your LDL cholesterol is.

It should be iterated that HDL cholesterol should be as high as possible – ideally above 40-50.  If it is above 60, 1 of the 5 cardiovascular risk factors can be taken away.  Triglycerides are not significant unless they are really high, but they shed some light into one’s dietary habits.  Remember that LDL cholesterol also corresponds to diet, while HDL cholesterol corresponds to physical activity.

What about sugars and such?

This too “depends.”  If you are fasting (nothing to eat for 8-12 hours), then your blood glucose (sugar) should be under 100.  That said, 100-126 puts you in a diabetic range, and over 126 on more than a few occasions is technically diabetic.  If you have eaten, that diabetic threshold is raised to 200.

What is more telling about your blood sugar control is a value called an A1c.  This gives an estimate of how well your sugars are controlled over a 3-month period.  Ideally this number should be under 5.7.  5.7-6.4 denotes a pre-diabetic range, and 6.5 and above is diabetic.

What about the thyroid, blood counts (CBC), and my electrolytes, kidney, and liver?

Breaking down these values is beyond the scope of this article…just know that you want these to be normal.  A few trends are worth mentioning however:

·         The creatinine value, which serves as a surrogate for kidney function, is generally higher for African Americans, and most lab scales account for this.  Also, this value is slightly higher in those with muscular builds.

·         If your ALT liver value is elevated MORE than your AST liver value, this is likely an indication that you are consuming too much fat in your diet.

·         If your AST liver value is elevated MORE than your ALT liver value, this is likely an indication that you are consuming too much alcohol.

·         It is not uncommon for some persons, particularly African Americans, to have slightly low white blood cell values.