High cholesterol levels can exist for years without ever causing any symptoms. Sometimes the only warning sign is a heart attack or stroke as the arteries become severely blocked due to plaque buildup. Getting your cholesterol levels checked on a regular basis can detect high levels before serious illness occurs, and a fasting cholesterol test is the one that is usually performed.
Types of Cholesterol
A fasting cholesterol test can detect your total cholesterol level, the levels of both the good and bad kind of cholesterol, and triglycerides. Cholesterol cannot dissolve in the blood so it must be transported by carriers. One type of carrier is low-density lipoprotein, or LDL, which is considered the bad kind, because LDLs take cholesterol to be stored. The other carrier is high-density lipoprotein, or HDL, which is considered the good kind, because HDLs take cholesterol to be excreted. Triglycerides are a type of fat that circulates in the blood. Triglycerides are also transported by LDLs and HDLs as well as very-low-density lipoproteins, or VLDLs, and chylomicrons, or CMs. Since cholesterol levels can be high without ever causing symptoms, MedlinePlus recommends having a cholesterol test between the ages of 25 to 35, whenever there are risk factors for heart disease present and then every five years, unless a physician recommends otherwise.
Benefits
The simplest test is a non-fasting cholesterol test, which only measures your total cholesterol level. While it is important to keep total cholesterol levels low, it is equally important to know what percentages of total cholesterol comprise LDLs, HDLs and triglycerides. Having a high level of HDLs provides a protective effect against heart disease, while a low HDL level increases your risk. The lower your LDL and triglyceride readings, the better. To fully understand your risk for disease, a fasting cholesterol test is best, because triglyceride levels can rise dramatically for hours after a meal and after ingesting alcohol, reports the Harvard Medical School Family Health Guide. Fasting before the test provies a more accurate reading.
Procedure
To prepare for a fasting cholesterol test, it is important to avoid all food and beverages except water for nine to 12 hours before your test, notes MayoClinic.com. Since some medications can affect cholesterol levels, a physician may recommend not taking certain drugs while fasting, or even for a few days before the test. At the doctor's office, a small sample of blood is drawn from your arm. The test takes just a few minutes and the results are sent to a lab. It can take a few days to a week to get the results.
Results
High levels of triglycerides and LDL cholesterol contribute to the buildup of plaque along the blood vessel walls. This causes the blood vessels to be come hard and narrow, which restricts blood flow. Over time, this can lead to high blood pressure, and if blood flow to the heart is restricted, a heart attack can occur. If the brain does not get the blood and oxygen it needs, a stroke can occur. The American Heart Association suggests keeping total cholesterol levels at 200 mg/dL or less, HDL levels at 60 mg/dL or higher, LDL levels at less than 100 mg/dL, and triglyceride levels at less then 150 mg/dL. A physician may set different levels, based on other risk factors that are present.
