I fell down the stairs two days ago, but I was close to the bottom, so I probably only fell down about 3 or 4 stairs and landed on my tailbone, then quickly got up. I was carrying a heavy bag on my shoulders when I fell, but I didn't have any pain for the rest of the day. However, yesterday, when I woke up, my shoulder hurt when I moved it certain ways, and my hips, knees and ankles were sore when I walked. It was painful, but very manageable, not unbearable by any means. Last night, I got up to go to the washroom, and as soon as I put pressure on my right foot, my knee was in excruciating pain, and I could not walk on it whatsoever. I limped to the washroom and back to my bed, and just went back to sleep. It only hurt when I put pressure on it, not when I was lying down. When I got up this morning, I was a bit sore in my hips, shoulder, ankles, and knees like I was yesterday, but I can walk just fine and the pain isn't nearly as bad as it was last night. Why did the intense pain come and go? What should I do?