By the age of 18 months, a parent should check for the following symptoms and in case of lacking criteria, one should immediately seek advice from a pediatrician.
General Screening
Observe if the child sits by itself in a chair.
Observe if the child builds a tower of 3 to 4 cubes.
Observe if the child walks up and down the stairs with support.
Make sure that you are brushing your child’s teeth every day.
Observe if the child’s behavior is normal.
Vision Screening
Place a thread or small pellet (smaller than used for 6 months) on the table and observe if the child picks it up.
Hearing Screening
Take a test where one person distracts the child’s attention while the other makes sound with a rattle on both sides alternately above and below at 3-6 feet behind at the infant’s ear level. Now observe in the child turns head towards the sound.