The main hazards of intravenous infusion for babies mainly include potentially increasing the burden on the child's lungs, developing drug resistance, and causing adverse reactions. Here are some specific details:

1. Increasing the Burden on the Child's Lungs

The narrowest blood vessels in the human body are no larger than 10 nanometers. Therefore, if the particles of intravenous infusion drugs are too large, they can easily block the blood vessels and even cause damage to them. Furthermore, when the drugs enter the bloodstream, particles with diameters larger than the blood vessels will be retained in the lungs, leading to lung fibrosis, which can decrease respiratory function and affect the overall oxygen supply to the body, thus hampering daily life and work. Therefore, it is best for parents to avoid intravenous infusion for their children.

2. Developing Drug Resistance

Frequent intravenous infusion can lead to the formation of a "drip disease" in the body. Compared to oral medications, intravenous infusion has a much higher probability of allergic reactions and is more likely to cause drug resistance. This can result in the child's inability to recover from the same illness without intravenous infusion in the future. Therefore, it is not recommended for parents to bring their children for intravenous infusion.

3. Causing Adverse Reactions

All drugs have certain side effects, varying in their degree of harm to the human body. Oral medications enter the body and then the bloodstream slowly, resulting in mild adverse reactions and less harm to the body. However, when drugs are administered intravenously, they can directly enter the bloodstream, leading to adverse reactions such as fever and, in severe cases, even death. Therefore, unless the situation is critical, parents should consider administering intramuscular injections to their children.