Cholesterol needs to be maintained within a normal range and not lower is better. Cholesterol is a very important substance for the human body and it should be properly understood. If the cholesterol level is too low, it cannot perform its normal physiological functions and the human body will experience some corresponding diseases or symptoms: 1. The immunity of the body is affected Cholesterol is an essential component of the composition of cell membranes, which can maintain the normal function of cells, if its level is too low, it will affect the composition of cell membranes, resulting in the cells not being able to perform their normal physiological functions. For example, if cholesterol is too low, the brittleness of red blood cells will increase and people will be prone to many diseases.2. The digestion and absorption of lipid foods are affected by the fact that cholesterol can form bile acids to help digest lipid foods, so its low level will affect the formation of bile, resulting in limited digestion and absorption of lipid-rich foods.3. Bone health is affected by the fact that 7-dehydrocholesterol in the skin can be turned into vitamin D under ultraviolet light exposure from the sun. 7-dehydrocholesterol in the skin can be converted to vitamin D under UV exposure, which affects the body’s absorption of calcium and is essential for bone health.4. Vascular health is affected HDL cholesterol transports metabolic products from cells, including harmful cholesterol, to the liver for processing to avoid their deposition in the blood vessel walls. If cholesterol levels are too low, this effect is diminished, so the body’s vascular health is affected. In addition, low cholesterol causes increased cell membrane fragility, which makes the blood vessel walls fragile as well, and increases the risk of rupture and bleeding in the cerebral vessels if a sudden rise in blood pressure is encountered.5. Mental health is affected Cholesterol is highest in the brain and nerve tissue, accounting for about 1/4 of the total amount in the body, and it is also a component of the nerve myelin sheath. Therefore, when cholesterol levels are low, it can affect neurological function and mental state.