A hernia occurs when an organ or fatty tissue squeezes through a weak spot in a surrounding muscle or connective tissue called fascia. The most common types of hernia are inguinal (inner groin), incisional (resulting from an incision), femoral (outer groin), umbilical (belly button), and hiatal (upper stomach). It can often be harmless and pain-free, but at times it can bring discomfort and pain.
In adults, hernias are most common in the groin or abdomen, according to NYU Langone Health. (1) When you have a hernia, you may see or feel a bulge in one of these areas. You may also experience pain that worsens during certain activities, such as when you lift something or stand for a long period of time.
You can develop a hernia all of a sudden after you bend, cough, laugh, or lift weights or heavy items. Alternatively, it can form over a period of weeks or months.
Most hernias are external, which means the tissue is pushing through the abdominal wall toward the outside of the body. This often creates a bulge that you can see. But a hernia can also be internal, which means that it remains inside the body (within the abdomen).