<s>[INST] My 20 month old daughter fell of a chair 2hours ago. She cried for a while but seems okay. She ate her Lunch and drank her milk and is now sleeping. When she fell her behavior didn t change. I have noticed a lump on the right side of her head. How long will the lump take to go down. Should I take her to the emergency room to be checked over or should I wait the 24 hours. How does one know whether there is fluid build up. [/INST] Hits very difficult to take care of baby at this age. Lump on the right side of head after trauma is due to subcutaneous swelling. As you are saying there in no change of behavior it's good. However keep an eye for complaints like headache, dizziness, vomiting, seizures & breathing difficulty.don't worry now your baby is quite well. If any above symptoms seen take baby to emergency immediately. Thank with best regardsVasundhara </s>