Do your shins ache after your runs or just after a good days walk?
It could be shin splints. You might hear some professionals call it medial tibial stress syndrome. The cause is stress on your shinbone and the connective tissues that attach muscles to your bones. They get inflamed and painful, either on the front outer part of your leg (anterior shin splints) or the inside of your leg (medial shin splints).
This common problem can result from:
Flat feet -- when the impact of a step makes your foot's arch collapse (commonly called over-pronation)
Shoes that around past their time.
Weak feet - ankles, hips, or core muscles
NOT all shin pain is shin splints, if you have pain on the anterior (outside) of the shin this maybe be something called compartment syndrome. A condition that where the muscle swells and creates pressure. You may also have some leg pain, unusual nerve sensation and muscle weakness.
Pain in the lower leg pain maybe a stress fracture, if that's the case, try running your finger/thumb down the front of the shin and if you have one specific hotspot (pain). Shin Splints are at the most painful in the mornings when the muscle have tightens up, also when you lift the foot up and flex at the ankle.
So what can you do to help Shin Splints?
If you're running on the roads, try taking if off-road on some soft terrain. This will help soften the impact. You may also want to check you running shoes, as the cushion in shoes will lose their shock-absorbing capabilities.
Dial back on the running or if its very painful you may need to take a few days off. Sometimes ramping up the mileage to quickly is just too much overload for your body.
Here you can find some exercises to do if you are suffering from shin splints -
Give these exercises about and see how you get on.