These are the top 5 medical mistakes that happen most often in healthcare: 1. It's a medicine mistake if you buy, sell, or give medicine and something goes wrong, like using the wrong drug or amount. 2. If a doctor makes a mistake in the diagnosis, they might not start the proper medicine or give it at all. This is called a diagnostic medical error. 3. These are mistakes that doctors make during surgery, like picking the wrong spot or leaving tools inside the patient. 4. People getting medical care go from one source to another sometimes without being able to talk to each other. These are known as "handoff healthcare errors," they can leave out or change information. 5. Hospital-acquired diseases can occur if healthcare professionals do not take proper steps for infection control.