"pain spread" is correct and usable in written English.
You could use it to describe a feeling or sensation. For example: "As she slowly moved her arm, pain spread throughout her body."
"The pain spread to my other toes and never went away," she said.
Then she injured her neck, and excruciating pain spread to her shoulders.
Over the next several days, the pain spread to the entire right half of his face.
It made Annelise extremely sleepy, and the pain spread to the tips of her toes.
As the pain spread it has seeped into Louisiana, but slowly.
Rather, pain is best represented by a continuum of "widespreadness" from localized pain to pain spread across the body.
As the economic pain spreads to Germany and France, political pressure rises for Ms. Merkel and Mr. Hollande to find a solution.
Even in the dark she could sense the resigned smile, the smile with cynicism in it as well as pain, spreading crookedly across his bearded face.
When the pain spreads from the stock market to the real economy and rising unemployment returns to the US, protectionist pressures in Congress will grow.
With futures markets predicting property-price falls of up to 30% and the pain spreading beyond mortgages, the bottom may be months away.
A heart attack is usually marked by a feeling of pressure, tightening, or crushing pain in the center of the chest, and that pain spreads to the back, neck, jaw, shoulders, and arms — especially the left arm.
