Generally speaking, when your groin begins to show signs of pain, inflammation, or decreased range of motion, you need to get to the doctor to have it looked into sooner rather than later.
Groin pain can occur more often in those that are involved in athletics, as this type of soreness and pulling the groin area can be common in sports such as football. These types of groin predicaments due to athletic over-extensions, but they also can often be healed with minimal treatments.
When a severe hernia has developed, it can literally knock the wind out of you. Many collapse from the pains not knowing they have a hernia yet, which makes it imperative to consult with your medical provider at the first onset of pain.