While it is rare for any child younger than 5 to suffer from attention-deficit hyperactivity disorder (ADHD), it's not impossible. Because toddlers have so much energy, it's hard to distinguish between a normally active toddler and a hyperactive one. Thus your doctor's feedback should be indispensable; if necessary, she'll refer you to a child psychologist, who can prescribe therapy or medication.
Since your child has so much energy, make proper use of it. Take your child to the park and have him do laps. Give your child age-appropriate blocks and let him experiment with building and knocking things down. Try to limit the amount of time that your child spends in places where he can't run around and has to sit still.
Make sure that your toddler is getting enough sleep: at least 12 to 14 hours. Your child may just be acting out because he's tired. Also, kids often act out when they're hungry. Give your toddler a protein-rich breakfast such as eggs or crackers with fresh peanut butter.