To inflict means to cause something painful or unpleasant. A person or thing can inflict something on someone either purposely or accidentally, but the result is always negative.
Ex: Josh was so angry with his friend Mike that he tried to inflict emotional pain on Mike by insulting his physical appearance, calling him ugly, old, and short.
Ex: Even though dentists are just trying to help, the metal instruments are so sharp that dental cleanings often inflict pain on the patient.
Something that inflicts more negative results than positive ones is often to cause more harm than good. The phrase causes more harm than good is often used as a warning to others to avoid the object or situation described.
Ex: Counsellors can be very helpful. However, their actions can cause more harm than good if they don't have all the information and give the wrong advice to their patient.
Ex: Eating well and exercise can be very good for your health. But cutting too much food from your diet can cause more harm than good if you're not getting the right nutrients in your body.
To result in something means to cause something to happen. An action or event can result in a number of different effects or results.
Ex: Amy knew that you should never go to the supermarket, but she did it anyway. Her decision resulted in a £300 shop, compared to the £150 she normally spends.
Ex: Most children know that riding a bike without a helmet can result in injury. But they often do it anyway because helmets are heavy and uncomfortable to wear.
The phrase unexpected results are often used to describe a consequence that was not predicted or intended to happen after a specific action. You could also say the results were unexpected.
Ex: Simon was surprised by the unexpected results of his experiment. He had no idea that mixing the two chemicals in that way would create such a big explosion.
Ex: The results of the election were very unexpected. Most people believed the new candidate was sure to lose, but she had so many votes that her victory was shockingly large.