Hematomas can form under the skin after impact, leading to swelling, discoloration, and pressure

https://smb.austindailyherald.com/article/Atlantas-Hurt-911-Injury-Centers-Revolutionizes-Car-Accident-Recovery-with-Doctor-Led-Care-and-Legal-Support?storyId=6827816017bc4f0008d9ab83

Hematomas can form under the skin after impact, leading to swelling, discoloration, and pressure, sometimes needing drainage if large and painful.