Nutrient injection is the injection of some nutrients into the body by means of intravenous medication. In clinical practice, the most common and easy to think of people who need to apply nutrients intravenously are those who are not able to eat or drink, such as people with gastrointestinal bleeding, who are not able to absorb any water or nutrients through digestion in the gastrointestinal tract during treatment, because if they eat, it will cause the gastrointestinal bleeding to continue, so they will need intravenous hydration, as well as the corresponding nutrients. Another part of the population may be significantly anemic or have other nutrient deficiencies, which may also require nutritional injections. For example, when cirrhosis is evident with ascites, the liver’s ability to synthesize albumin is reduced, and even with better oral nutrients, it is difficult for the liver to convert it into albumin, which may require a human albumin infusion in order to increase the patient’s colloid osmotic pressure.