If my abdomen and lower parts go numb after a hernia surgery, is that normal? I went in for a double hernia that was caused by lifting to much weight. The belly button and left lower areas were effected. The doctor said the cut would be small and it would

Some numbness common. It depends on what type of hernia repair you had done. It's not uncommon to have numbness around the incisions after surgery. If you had a laparoscopic hernia repair, that should be minimal. Open hernia repairs are associated with some incidence of numbness on the inside of the thigh and scrotum. Sometimes it gets better over time.
It . It is very common to have numbness in the area of hernia repair. This can be caused by multiple factors, some of which are self limited, while others are permanent. First, some minor small nerve endings are divided at the skin incision site, and is completely unavoidable. This typically affects the area just at and immediately surrounding the incision site, and it improves with time. Second, some nerves are manipulated (stretched) during some hernia repairs (this depends on the type of hernia and technique of repair). This usually causes a temporary nerve dysfunction which will improve in time. This may last from just a few weeks to many months and maybe even a year. Finally, in some hernia repairs, many surgeons purposely divide nerves. This will cause a permanent loss of sensation, but avoids the pitfall of chronic pain that can be a complication of hernia repair. Feel free to ask your surgeon about this. He/she should be happy to answer this question.