What Could Excessive Muscle Joint Pain Suggest?

in the last 2 weeks i have had aches and muscle joint pain similar to that of someone who was in a car accident the day before and really tired but not feeling sick just pain and sleepiness what would cause this i ache in my back , arms wrists shoulders where my legs meet my body those " joints" hurt reallllly badly. I havent changed anything in my daily rutuine other than the fact that i have gained 11 pounds in the last month month and a half