Taking anti-inflammatory drugs after surgery is fairly standard protocol. But a new study from researchers at Michigan State University suggests this approach may be backfiring and that blocking inflammation during this critical time may, in fact, delay recovery and prolong pain rather than relieve it.

In the new study, published recently in the Journal of Pain Research, the researchers report that letting inflammation run its course led to a quicker cessation of pain and an overall quicker recovery after a surgery or injury.

“The idea was that blocking inflammation would reduce pain overall,” said Geoffroy Laumet, the study’s senior author and associate professor in the Department of Physiology and the Neuroscience Program at MSU. “Instead, blocking inflammation increased pain in the long run. It was an unexpected result.”

The team used a mouse model to study postoperative pain with versus without activity from a key immune signaling molecule called TNF-α, or tumor necrosis factor alpha. To compare, they inhibited TNF-α, which is involved in promoting inflammation, and mimicked surgery with a small incision. They expected that blocking TNF-α would reduce pain, but the opposite happened: The mice stayed in pain for much longer. “It prevented the body from turning off the pain normally,” Laumet explained.