Hernias are areas of weakness in the abdominal wall that lead to a bulging of abdominal contents through the abdominal wall. This can cause a lump, and may cause pain. They can occur at natural points of weakness (e.g. in the groin or around the umbilicus), or at sites of previous surgical wounds.
Treatment can be with either keyhole surgery, or open surgery. It is also possible to treat some hernias under local anaesthetic, without the need for general anaesthetic. In most cases, this can be done as a daycase procedure.
The aim of surgery is to fix the area of weakness, and reinforce this area with sutures or a mesh (a synthetic sheet of material that provides a strong framework for body tissues to grow into).
For more detail, follow these links to trusted sources:
NHS website
https://www.nhs.uk/conditions/hernia/
Cleveland Clinic
https://my.clevelandclinic.org/health/diseases/15757-hernia