"Blood Lipids" are fat-like substances found in the blood and body tissues, including cholesterol and triglycerides. The body needs small amounts of lipids to work normally. Some people have too much cholesterol (fat) in their blood and this increases their chances of having a heart attack. “血脂”是血液和身体组织中发现的类似脂肪的物质，包括胆固醇和甘油三酯。身体需要少量脂质才能正常工作。有些人血液中胆固醇（脂肪）过多，这增加了他们患心脏病的几率。

Cholesterol is mainly made when the liver breaks down saturated fats in food. This cholesterol then passes into the blood. Cholesterol travels in the bloodstream in two forms:

• Low Density Lipoprotien (LDL), or "bad" cholesterol, is the main lipid that causes damaging buildup and blockage in the arteries. 低密度脂蛋白（LDL）或“坏”胆固醇是导致动脉损伤性积聚和堵塞的主要脂质。
• High Density Lipoprotein (HDL) is actually a "good" type of cholesterol that helps to prevent cholesterol from building up in the arteries.

Triglyceride is another lipid that may increase the risk for heart disease.

普通体检血脂四项是常规检查项目，包括：总胆固醇（TCHO）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL）和低密度脂蛋白胆固醇（LDL）。正常值：

• 总胆固醇（TCHO）：3.0-5.7 mmol/L
• 甘油三酯（TG）：0.5-1.7 mmol/L
• 高密度脂蛋白胆固醇（HDL）：0.9-1.8 mmol/L
• 低密度脂蛋白胆固醇（LDL）：2.1-3.1 mmol/L

Blood lipids are measured in units called millimols per litre of blood, usually shortened to 'mmol/l'. Milli- is added to some nouns that refer to units of measurement in order to form other nouns referring to units a thousand times smaller.

The mole is the unit of measurement for amount of substance in the International System of Units (SI). It is defined as exactly 6.02214076×10²³ particles, which may be atoms, molecules, ions, or electrons. The definition was adopted in November 2018 as one of the seven SI base units, revising the previous definition that specified one mole as the amount of substance in 12 grams of carbon-12 (12C), an isotope of carbon.

The number 6.02214076×10²³ (the Avogadro number) was chosen so that the mass of one mole of a chemical compound in grams is numerically equal, for most practical purposes, to the average mass of one molecule of the compound in daltons. 选择数字6.02214076×10²³（阿伏伽德罗数），以便在大多数实际情况下，一摩尔化合物的质量（单位：克）在数值上等于该化合物一个分子的平均质量（单位：道尔顿）。Thus, for example, one mole of water contains 6.02214076×10²³ molecules, whose total mass is about 18.015 grams and the mean mass of one molecule of water is about 18.015 daltons. 因此，例如，一摩尔水含有6.02214076×10²³个分子，其总质量约为18.015克，一个水分子的平均质量约为18.015道尔顿。

质子和中子质量一样，统称为核子。一个碳-12原子有12个核子(6质子＋6中子)，质量是核子的12倍。

1摩尔核子就是1阿伏伽德罗数个核子，质量是1克。1摩尔碳-12原子就是1阿伏伽德罗数个碳-12原子，质量是12克。像K, M, G一样，摩尔是数量单位。一般用B指字节byte，b指bit位。1K是1000还是1024(2的10次方)有歧义，进而M, G等也有。

一个碳-12原子的质量是1.993×10^-26千克 。1.993×10^-26 × 6.02214076×10²³ = 12.00212653468 克。