The reason why the injection site is different as skin, blood vessel, and muscle
After Corona 19, people who were reluctant to get an injection were forced to get a vaccine shot. I was vaccinated at least 2 times and at most 4 times, and there are more people who get flu shots in preparation for the flu epidemic.
One of the questions I get from frequent injections is the area where the injection is given. I wonder why vaccinations, including the Corona 19 vaccine, are only given to the arm. I usually imagine sticking out my butt when getting an injection in a hospital, but vaccination is completely different.
Injections are prescribed to speed up the effects of the medicine. It is sometimes prescribed when taking medication by mouth does not work. The injection sites include the skin, blood vessels, and muscles. The rate at which the drug is absorbed is fastest in blood vessels. Then muscle, then skin.
Depending on where the drug is injected, intradermal injection in which a small amount is injected between the epidermis and dermis, subcutaneous injection in the subcutaneous fat under the dermis, intramuscular injection in the muscle of the arm or buttocks, intravenous injection and arterial injection directly into the blood vessel divided into etc.
Intradermal injection is used to inject vaccines, serum, and drug solutions between the dermis. It is mainly used to examine local reactions of the skin or localized reactions to the skin. It is an injection method used for diagnosis and prevention of disease, not treatment, and is usually placed on the inside of the forearm or the outside of the upper arm.
Insulin, a drug for treating diabetes, is usually administered by injection because it is digested in the stomach when taken orally. The method of insulin administration is subcutaneous injection. Subcutaneous injections are absorbed faster than oral drugs, do not interfere with digestive juices, and do not burden the liver. Some hemostatic agents, vitamins, and cardiotonic agents are also administered by subcutaneous injection.
An injection into the buttock is an intramuscular injection. Absorption is fast because muscles have abundant blood vessels. The injection is usually given outside the buttocks, but sometimes it is given on the outside of the upper arm. The effect is faster when it hits the hip than the arm. If you press down after injection, absorption will be better. The reason why doctors and nurses ask you to relax when receiving an intramuscular injection is because it is difficult to insert the needle when the muscles are stiff. When a muscle is stiff, it hurts more than when it is not.
The COVID-19 vaccine and influenza vaccine are intramuscular injections, but the reason why they are placed on the arm rather than the hip is to inoculate many people quickly. To place it on the hip, it takes a lot of time to lower and raise the bottom, and a wider space is required because the lower part (?) needs to be exposed. The time and space cost is higher than that of the arm.
It is an intravenous injection that is administered into a vein on the back of the hand, wrist, or inside the elbow. In the case of intravenous injection, the drug reaches the necessary tissues of the body through the heart within 1 to 2 minutes, so the effect is fast and the response is certain. However, because the drug enters the body suddenly, if it is too strong or does not suit the body, the condition may not be good. In extreme cases, it can even lead to death. Arterial injection is a direct injection of drugs into an artery and is used in special cases such as malignant tumor treatment.