The key indicators for blood lipid health testing primarily include total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C).

The normal ranges of these indicators and their relationship to health are as follows:

1. Total Cholesterol (TC)
   • Normal Range: It is generally considered that the normal value of total cholesterol should be less than 5.18 mmol/L (or 200 mg/dl), with some sources indicating less than 5.2 mmol/L (note: the unit 'ml' is incorrect here, it should be 'mg' for cholesterol measurements). However, this value may vary slightly depending on different laboratories and testing methods.
   • Health Relationship: Elevated levels of total cholesterol are associated with an increased risk of cardiovascular diseases such as atherosclerosis.
2. Triglycerides (TG)
   • Normal Range: The normal value of triglycerides should be less than 1.7 mmol/L (or 150 mg/dl). Some sources also indicate less than 1.76 mmol/L (or 150 mg/dl).
   • Health Relationship: High levels of triglycerides can lead to hypertriglyceridemia, which in turn increases the risk of cardiovascular diseases. Especially when triglyceride levels exceed 5 mmol/L, it may trigger acute or chronic pancreatitis.
3. High-Density Lipoprotein Cholesterol (HDL-C)
   • Normal Range: The normal value of HDL-C should be greater than 1.04 mmol/L (or 40 mg/dl), with some sources indicating a range of 1.16 to 1.55 mmol/L.
   • Health Relationship: HDL-C is considered "good cholesterol" because it helps transport cholesterol from artery walls back to the liver for metabolism, thereby reducing the risk of cardiovascular diseases.
4. Low-Density Lipoprotein Cholesterol (LDL-C)
   • Normal Range: The normal value of LDL-C should be less than 3.37 mmol/L (or 130 mg/dl), with some sources indicating less than 3.4 mmol/L (or 120 mg/dl). For patients with coronary heart disease and hypertension, the control target for LDL-C should be even lower.
   • Health Relationship: LDL-C is considered "bad cholesterol" because it tends to accumulate on artery walls, forming atherosclerotic plaques, which increases the risk of cardiovascular diseases.

Notes:

• Blood lipid tests should be performed in a fasting state to ensure the accuracy of the results.
• Blood lipid levels are influenced by various factors, including diet, exercise, age, gender, and genetics. Therefore, when interpreting blood lipid test results, these factors should be considered comprehensively.
• If blood lipid test results are abnormal, it is recommended to seek medical attention promptly and make corresponding treatment and lifestyle adjustments based on the doctor's advice.