(WHTM) — I recently underwent a procedure requiring me to have local anesthesia placed in the area where the doctor was working. I felt nothing and it was wonderful not worrying about pain while the doctor worked on me.

But, during the procedure, I wondered how this all worked. What allowed me to sit fully awake and not be in pain?

So, what is local anesthesia and how does it work? First, there are two kinds: general and local. General anesthesia requires expert care as you breathe in gas or get an injection that causes you to be unconscious. Since you’re unconscious, your heartbeat, respiration, oxygenation, and blood pressure must be watched carefully. This also carries the risk of side effects when you wake up, such as nausea.

Local anesthesia is a one-time injection of medicine that numbs a small area of the body.

When the doctor or nurse injects local anesthesia into an area. The medicine blocks the pain that the nerves give to your brain when poked and prodded. The drug numbs those receptors around where the medicine was injected.

WebMD says that there are two groups of drugs that are used. The commonly used drugs are amides like lignocaine, prilocaine, and bupivacaine. The other group is esters like cocaine, procaine, and amethocaine.

Local anesthesia wears off quickly. WebMD states that the effect of the commonly used local anesthetics wears off in about an hour. Sometimes, doctors may combine a local anesthetic with steroids or epinephrine. This works to prolong the drug.

There are some side effects to local anesthesia but there are far fewer chances of it happening. These side effects include tingling, ringing of the ears, headache, dizziness, or confusion.