What Could Pain And Numbness In Hand And Fingers Suggest?

Hello doctor, I have a question about my hand. I used to work in a deli, and one day I felt a pain in my right hand between my thumb and first finger. It went away but gradually grew into numbness in my thumb, first, and middle fingers. Eventually it moved to numbness in all the fingers on my right hand and my palm. I especially feel the numbness in my fingertips. It weird holding a pen and writing. I was just wondering what this could be?