The technique used to cause the absence of sensation in a certain body part is referred to as local anesthesia. It can be used for minor procedures as it does not cause unconsciousness, just local insensitivity to pain. Local anesthesia helps patients to go through surgical and dental procedures with reduced or no pain and distress. It can also be used to decrease the effects of non-surgical pain. The local anesthetic drug is used to cause reversible local anesthesia as well as a loss of nociception. The effects of local anesthesia particularly depend on the nerve pathways it uses. Loss of pain sensation known as analgesia and loss of muscle power termed as paralysis are the major effects caused by it. This book outlines the processes and applications of local anesthesia in detail. It presents researches and studies performed by experts across the globe. This book will provide comprehensive knowledge to the readers.