How do painkillers work?

Answer: They block pain signal chemicals

They numb all nerve endings — Wrong. Most painkillers don't numb nerves (except local anesthetics like novocaine). Common painkillers (NSAIDs like ibuprofen, aspirin) work by blocking prostaglandin production—chemicals that sensitize nerve endings to pain and cause inflammation. Acetaminophen (Tylenol) acts in the brain to reduce pain perception. They modulate pain signaling, not numb nerves.

They numb all nerve signals — Wrong. Painkillers don't numb all nerves—you'd lose all sensation. NSAIDs block specific enzymes that produce pain-signaling chemicals, while opioids bind to specific receptors in the nervous system.

They block pain signal chemicals ✓ — Correct! NSAIDs (ibuprofen, aspirin, naproxen) block COX enzymes that produce prostaglandins—chemicals that sensitize nerve endings to pain and cause inflammation. Less prostaglandin = less pain signaling and inflammation. Acetaminophen (Tylenol) works differently, acting in the brain to reduce pain perception through mechanisms not fully understood. Opioids work by binding to opioid receptors in brain/spinal cord, blocking pain transmission.