analgesic
An analgesic is a medicine whose job is to turn down pain without switching off the rest of you. Unlike a general anaesthetic, which puts the whole brain to sleep, an analgesic dials back the hurt while you stay awake, talking, and aware. Think of it as lowering the volume on a single loud channel rather than cutting all the power.
Analgesics work at many different points along the pain pathway. Some act in the periphery where tissue is damaged, reducing the chemical signals that make nerves fire (for example, the anti-inflammatory analgesics that block prostaglandin synthesis). Others act centrally, in the spinal cord and brain, changing how the painful signal is transmitted and felt (for example, the opioids acting on opioid receptors). Because the mechanisms differ, drugs from different classes are often combined to attack pain on several fronts at once.
Pain medicine is usually pictured as a ladder: start with simpler, milder agents such as paracetamol or an NSAID for mild pain, and step up to opioids for severe pain. But there is no single best analgesic for everyone. The right choice depends on the cause and type of pain, the patient's other illnesses, and the side-effect and dependence risks of each option — strong relief and serious harm often travel together.
After dental extraction, a patient is given paracetamol plus ibuprofen — two analgesics with different mechanisms — for better relief than either alone.
Combining analgesics from different classes is called multimodal analgesia.
Analgesics relieve pain but do not always treat its cause; masking the pain of a worsening problem (such as an undiagnosed infection or fracture) can be dangerous, so the source of pain still needs to be addressed.