I've been diagnosed with a blood disorder called Von Willebrand's, it causes easy bleeding and bruising.
Bruising on shins, thighs, and even arms is often no cause for alarm.
Naturally, other areas of bruising may be observed, but those listed are commonly found in intentional injury cases.
They are sweet but extremely playful, and when they start running and playfighting at the same time, they can be dangerous.