6. A bruise
The pain in your stomach could be caused by something as simple as a bruise. Just like any other part of the body, a bruise can develop in the stomach when it is experiencing a blunt impact.
For example, if you have received a blow to the stomach, if something has landed on your stomach, or if you have fallen, the flesh and muscle surrounding your stomach – or any other part of your abdomen – could become bruised.
This pain can range from mild to severe. If it gets worse over time, see a doctor, as this could be a sign of internal damage.