Why do i have dull aching pain in lower back radiating into groin and down leg?

?Hernia ?Back Disc: Sometimes small hernias in the groin will push on nerves very early, before you can feel a lump, and cause the kind of pain that you're describing. Another possibility is a herniated disc in your back, pressing on the nerves to go to these areas. You need to see a physician to sort this out, may need x-rays, and perhaps even a referral to a specialist. Good luck and get well soon!