Hi there, That is a very good question. The blood clots that you are concerned about is when a clot becomes dislodged IN an artery or vein. A hematoma is on the OUTSIDE surface of a blood vessel. When your mother fell and hit her head, the wall of the vessel on her forehead became damaged and blood leaked into the surrounding tissue. Regarding her bad headache, anytime our blood escapes from its normal blood stream, it can be very irritating and cause inflammation to that area. Signs of inflammation include swelling, redness and pain. Typically, the area around a hematoma is inflamed and when it starts to break up, she will feel it. The doctor is very correct on what is causing the headaches. To answer your question about being worried about a blood clot or death, I would have to say no because she already had a CT scan of her head and nothing was seen. Again, the hematoma is on the outside of the vessel. She is very lucky as some head injuries can cause bleeding of the brain. Have a good day and let me know if you have any other questions or concerns. :)