Difference Between Analgesia and Anesthesia

The key difference between analgesia and anesthesia is that the anesthesia is an induced, temporary state with one or more of the following characteristics: analgesia (relief from or prevention of pain), paralysis (extreme muscle relaxation), amnesia (loss of memory), and unconsciousness. Analgesia can be achieved by giving a pain killer or an analgesic to the patient. Basically, analgesia is a part of anesthesia. Anesthesia is given in carefully selected situations and, in contrast, analgesia is given whenever a patient needs pain relief.

What is Anesthesia?

Anesthesia can be achieved locally (local anesthesia) or to the entire body (general anesthesia).

Local Anesthesia

Local anesthesia is given for local surgery or for local pain release in a condition affecting only a part of the body. There are several ways of giving local anesthesia.

Spinal Anesthesia:

The anesthetic agents are given to the space surrounding the spinal nerve roots which will anesthetize the region below that spinal level. This is used in lower limb surgeries as well as some minor abdominal surgeries such as caesarean section.

Epidural Anesthesia:

The anesthetic agent is injected into the epidural space in the spinal canal. This method is commonly used for pain relief after major abdominal surgeries.

Plexus block Anesthesia:

Nerve plexus supply upper and lower limbs. Plexus can be blocked by injecting an anesthetic agent around them. Brachial plexus are blocked in Axilla during upper limb surgeries. Lumbar plexus are blocked at the lower back during lower limb surgeries.

Nerve block Anesthesia:

Intercostal blocks are used in pain relief following rib fractures. Ring blocks are used in finger and toe surgeries.

General Anesthesia

General anesthesia in given when the patient needs unconsciousness. This includes major and complicated surgeries. During general anesthesia, multiple anesthetic agents are administered to achieve loss of consciousness, muscle paralysis, and pain relief.

What is analgesia?

Analgesia refers to the prevention of pain or pain relief. Analgesic agents can be administered by different routes; e.g. intramuscular, intravenous, subcutaneous. Analgesic agents are of different strengths and usually selected based on the intensity of the pain. Sometimes, multiple agents are administered when strong pain relief is required such as in major surgeries or injuries.

What is the difference between Analgesia and Anesthesia?


Anesthesia: Anesthesia is used when strong pain relief, as well as, muscle relaxation is required, such as surgeries involving deeper tissues planes.

Analgesia: Analgesia is used when only the pain relief is required, such as in post-surgical patients.


Anesthesia: Anesthesia usually needs a special setting such as surgical theater and special instruments.

Analgesia: Analgesia can be achieved even at home.


Anesthesia: Anesthesia needs the attention of specialized doctors (anesthetists)

Analgesia: Analgesia needs only the attention of doctors.


Anesthesia: Anesthesia may need patients to be connected to a ventilator.

Analgesia: Analgesic does not need such manipulations.


Anesthesia: In anesthesia, other drugs may need to be administered to achieve recovery.

Analgesia: Analgesic effect is gradually reduced when the drug is removed from the body.


Anesthesia: In anesthesia, the patient’s vital parameter such as blood pressure, heart rate needs to be monitored

Analgesia: Analgesic does not require monitoring.

Pain relief potential

Anesthesia: In anesthesia, complete pain relief can be achieved.

Analgesia: During simple analgesia, the pain relief potential is lesser than that.

Image Courtesy:

“Maquet Flow-I anesthesia machine” by DiverDave – Own work. [CC BY-SA 3.0] via Wikimedia Commons