The procedure is simple u have to undergo 12hours of overnight fasting before giving the blood sample to the phlebotomist. In between you may take water only but no food. The phlebotomist will collect around 3ml of blood sample. Now regarding the test proper it assesses the various lipids in your body. total cholesterol, high density cholesterol, low density cholesterol, very low density cholesterol and triglyceride. Among which only high density cholesterol is the beneficial one others are not. so higher value of other lipids is harmful for your cardiovascular system and need management.