My son turned 4 on Oct 31st and for a while now he has been complaining of being tired. We will go into a store and after 5-10 minutes he will say he's too tired to walk. He will go out side to play and after about 20 minutes he will be ready to come back in. Sometimes when he is watching cartoons with his siblings they will get up and dance and he will say he is too tired to dance. I'm not sure of his exact weight, he has an appt on Dec 10th. If I had to guess I would say he weighs about 30 lbs maybe. All of my kids are on the small side since birth. He's pretty short too. He still wears 2T size clothes. My 2 yr old wears 18 months. Anyways, I'm just concerned about him and I'm sure this is not normal for a child his age. Any ideas what the problem could be?