The words are similar in meaning but some distinct differences. Cure means to eliminate the disease entirely. Heal refers to wounds or injuries that are getting better and going away. Treat is just the process of fixing or attempting to fix any disease or injury. So you can treat a disease but that doesn't mean the person will be cured. Wounds will heal sometimes with or without treatment. etc.

A doctor treats a disease, or treats a patient. The "treatment" consists of whatever the doctor actually does. They may be completely successful, partly successful, or may not work at all. A wound, a body, or a person "heals." It means the gradual process of getting better. It may end up with the wound, body, or person being completely well, or just partly well. It often refers to physical damage: a broken bone, or a cut. It can be used as a transitive verb--the doctor healed the patient--but that is old-fashioned language. A doctor, or a treatment "cures" a patient or a disease when it is almost completely successful: the disease is completely gone. "Diabetes can be treated with insulin, but there is no known cure." "The doctor treated the broken bone by putting a cast on it, and told the patient that it would take six weeks to heal." "Not only did the laparoscopic surgery cure the cancer, it also left small incision that healed quickly and left almost no scar." "In the 1800s, doctors treated fever by bleeding their patients. This treatment did more harm than good."

hello Aleksander. Cure is restoration of health, recovery from disease. Treat is to give medical aid to and Heal is to restore to health.

Hopefully, it will help! I also give credit to David M. (below), as I used some of his explanationas and added a bit more=)