Don't know what this means 🙁

So my boyfriend this past Friday was at his work and he is a server at this restaurant. They carry the food on big metal platters, almost like a cookie sheet, but his co worker was carrying a stack of them above his head and ended up hitting my boyfriend on the side of his, on his temple. Ever since then he's been getting major headaches on the side of his head, and today he messaged me at almost 3 am telling me how much pain he is in, he barely ever complains about pain because he's strong but once he complains, I know it's bad. My heart hurts for him cause I hate seeing the ones I love in pain 😞 does anyone know what this could've caused?