For a proper understanding of your health, you must know how you stand compared to the normal, healthy condition. For instance, when the nurse tells you your blood pressure is "150 over 95", what does this mean; is it normal? Or if your blood sugar is 145 mg/dL, are you diabetic? Here are some paragraphs about the most common normal numbers you should know - blood pressure, blood cholesterol (and other lipids), blood sugar, and CRP levels - taken from our Disease Digest pages.

Blood pressure

Two numbers are used to describe blood pressure:

• Systolic. The systolic pressure (the higher and first number) measures the force that blood exerts on the artery walls as the heart contracts to pump out the blood.
• Diastolic. The diastolic pressure (the lower and second number) is the measurement of force as the heart relaxes to allow the blood to flow into the heart.

Blood pressure is measured in millimeters of mercury (mm Hg). A blood pressure reading is written like this: 120/80 mm Hg, where 120 is the systolic, and 80 is the diastolic blood pressure.

Blood pressures are now categorized as normal, prehypertension, hypertension stage 1, or hypertension stage 2. The categories are defined in this table:

Category	Systolic BP (mm Hg)		Diastolic BP (mm Hg)
Normal	below 120	and	below 80
Prehypertension	120 - 139	or	80 - 89
Hypertension Stage 1	140 -159	or	90 - 99
Hypertension Stage 2	160 and above	or	100 and above

There are three other types of hypertension that are of particular interest:

• Isolated Systolic Hypertension. This occurs when the systolic blood pressure is over 160 mm Hg but the diastolic pressure is normal. It's related to arteriosclerosis (hardening of the arteries).
• Pregnancy Induced Hypertension. This condition occurs during pregnancy if blood pressure increases by more than 15 mm Hg above normal.
• White Coat Hypertension. This form of hypertension is elevated blood pressure that occurs only during a visit to the doctor's office.

You can read more about all this in the Disease Digest " High Blood Pressure".

Blood lipids, including cholesterol

Lipoproteins are protein spheres that transport cholesterol, triglyceride, or other lipid molecules through the bloodstream. Most of the information about the effects of cholesterol and triglyceride actually concerns lipoproteins.

The cholesterol-carrying lipoproteins are commonly referred to as cholesterol. They comprise the low density lipoproteins (LDL), often called the "bad" cholesterol, and the high-density lipoproteins (HDL), referred to as the "good" cholesterol. The triglyceride-carrying lipoproteins are intermediate in density, and together with very-low density proteins, carry triglycerides.

• Desirable total cholesterol: below 200 mg/dL (5.17 mmol/L)
• Optimal LDL ('bad') cholesterol: below 100 mg/dL (2.6 mmol/L)
• Optimal HDL ('good') cholesterol: over 60 mg/dL (1.56 mmol/L)
• Normal triglyceride: below 150 mg/dL (1.7 mmol/L)

Dividing the total cholesterol by the HDL cholesterol levels gives a Total/HDL ratio:

• The ideal ratio is 3.5 or below.
• A ratio of 4.5 carries an average risk for cardiovascular disease.

You can read more about this in the Disease Digest " Cholesterol, Other Lipids, and Lipoproteins".

Blood sugar levels

Fasting Plasma Glucose: The American Diabetes Association has recommended the sole use of the fasting plasma glucose (FPG) test. It is a simple blood test taken after eight hours of fasting. In general, results indicate the following:

• FPG levels are considered normal up to 110 mg/dl (or 6.1 mmol/L).
• Levels between 110 and 125 (6.1 to 6.9 mmol/L) are referred to as impaired fasting glucose. They are only slightly above normal, but are considered to be risk factors for diabetes type 2 and its complications.
• Diabetes is diagnosed when FPG levels are 126 mg/dl (7.0 mmol/L) or higher on two different days.

Glucose Tolerance Test: A glucose tolerance test uses the following procedure: First, an FPG test is done. A blood test is then taken two hours later after drinking a special glucose solution:

• In people without diabetes, blood sugar increases modestly after drinking the glucose beverage and decreases after two hours.
• In diabetes, the initial increase is significant and the level remains high, 200 mg/dL (11.1 mmol/L) or more.
• Measurements that fall between 140 and 200 mg/dL (7.8 to 11.1 mmol/L) put a person at risk for diabetes and are referred to as impaired glucose tolerance.

Glycosylated Hemoglobin: This test examines blood levels of glycosylated (or glycated) hemoglobin, also known as hemoglobin A1c (HbA1c). Measuring glycated hemoglobin is useful for determining the severity of diabetes. The test is not affected by food intake so it can be taken at any time. In general, measurements suggest the following:

• Normal HbA1c levels should be below 7%.
• A level of 8% indicates diabetes, in 98% of cases.
• Levels above 11% indicate poor control of carbohydrates.

You can read more on this in the Disease Digest " Diabetes Type 2".

Two other lab tests

CRP (C-Reactive Protein):
Less than 1 mg/L: low risk of coronary artery disease (CAD)
1 to 3 mg/L: normal level, average risk of CAD
Over 3 mg/L: high risk of CHD

Total homocysteine:
Normal range is 5 to 15 micromol/L