The most common cause is lead-based paint. If floors have dust from old painted walls, or paint chips, a baby could breathe in lead dust, or suck on lead-dusted hands or toys.
Some toddlers eat paint chips or chew on lead-painted window sills and stair rails.
They can include fatigue, crankiness and stomach aches. A small amount of blood is taken from a finger prick or vein and tested for lead. Blood can be drawn at a doctor's office, hospital, clinic or lab. If you don't know where to bring your child for testing, call your local health department. All children six months to six years should be screened regularly.