I would first like to know what your physical activity is like. For example, if you are a runner or if you lift a lot of weights or if you have a physically demanding job, then the most likely possibility is that you have strained one of the muscles in your abdominal wall or one of the intercostal muscles that are between the ribs. If this is a muscle strain
, then it is likely to get worse if you press on the area or if you tense the muscles of your abdomen or if you take a deep breath in.
The treatment for a muscle strain is rest and, in particular, backing off any exercise regimen that you may be using right now. Additionally ice can be helpful, as can taking regular doses of an over the counter anti inflammatory medication like ibuprofen or naproxen.
In any case, you should see your primary care doctor
for a more thorough evaluation. They can help determine if this is just a muscle strain that is going to require a bit longer to get better, or if there is potentially a more serious cause. Again, please speak with your doctor.