Even if Cao Cao had cooperated with the treatment, it would have been difficult for Hua Tuo to cure Cao Cao's headache. While Hua Tuo's medical skills were excellent, considering the many external factors, even if Hua Tuo did cure Cao Cao's headache, it would eventually recur due to Cao Cao's suspicion, so basically, Cao Cao's illness could not be cured.
First of all, the medical conditions at the time were too poor for Hua Tuo to perform surgery. At that time, Cao Cao's headaches were so severe and recurring that he invited the miracle doctor Hua Tuo to come and treat him; Hua Tuo believed that the root cause of Cao Cao's headaches was in his head, and that he needed to drink the Ma Bo San, and then cut open his head with a sharp axe to take out the deterioration inside before he could get rid of the root cause of the disease; however, there was no such advanced medical equipment as that provided by the current medical equipment at that time, so the risk of performing this kind of brain surgery was very great, and the slightest caution could lead to infection. The slightest carelessness would lead to an infected situation, which could easily result in a life-threatening situation.
Additionally, Cao Cao's own paranoia was too great, so even if he was cured of the headache, it wouldn't help. Because of the need to work on national affairs, Cao Cao often did not have a good rest, and over time it will definitely affect his health; even if Cao Cao is lucky to survive the operation, but due to his own character defects, Cao Cao is extremely uneasy about the people around him, and often worried that others will harm him. Unless one is able to look away, one will fall deeper and deeper into it, ultimately endangering one's own life.
So, Cao Cao's headaches were partly physiological and partly from his heart demons. Hua Tuo's medical skills were certainly brilliant, and he even had a high degree of certainty that he would be able to cure Cao Cao's headaches, but it was a foregone conclusion that Cao Cao would ultimately die as a result of his own personality.