All active children bump, not just their heads, but also other parts of their bodies while playing, climbing, jumping, etc. If after having bumped her head your child is fine and busy playing there is little cause for worry. However it does make sense to keep an eye on her as sometimes a bump on the head can result in delayed worrying symptoms such as dizziness, nausea and headaches. If any of these symptoms occur consult a doctor at once. When a person hurts herself, if the contact is hard enough the blood vessels are damaged, leading to bruises. Sometimes, though, the injury may not be severe enough to cause a bruise and instead the body may protect itself by causing a small swelling in the affected area. This is the knot or bump that we see.
These injuries usually subside on their own but to help lessen the pain a cold compress can be applied, even an icy-cold one. Wrap some ice in a cloth and place gently against the swelling or dip a cloth in cold water and wipe the bump. Another treatment to reduce the swelling and pain is to rub Arnica leaves on the injury which will help in improving circulation and ease the pain.
answered by G M