Symptoms

Many parents of children who suffer from autism suspect something may be wrong with their child by the age of 18 months and generally seek medical help when the kid is 2 years old. Typical difficulties noticed in autistic children:

• Social interaction
• Playing
• Verbal communication
• Nonverbal communication

There are cases when children seem to be normal before the age of 1 - 2 years and suddenly regress comes. Children start losing social and language skills they have learnt. This is regressive autism.
People suffering from autism may often:     

• Be sensitive in touch, sight, smell, taste, hearing (they cannot wear itchy clothes; become stressed if forced to do something)
• Get distressed when their routine is changed
• Make certain bady movements repeatedly
• Have unusual attachment to some objects

In fact, the signs differ from moderate to very severe.

Communication difficulties generally include:

• Inability to start and maintain a conversation
• Prefer to use gestures rather than words
• Poor language skills or none at all
• Inability to look at the objects at which other people are looking
• Inability to refer to self (for instance, might say "you want to eat " which means "I want to eat")
• Cannot point to direct smbs' attention to certain objects (often at the age of 14 months)
• Often repeats some memorized expressions, like those used in commercials
• Nonsense rhyming may also be present

Interaction with other people:

• Cannot play interactive games
• Generally cannot make friends
• Does not react to smiles or eye contact, or avoids eye contact
• Treat other people as though they are some objects
• Often stays alone instead of spending time with other children
• Lack of empathy

Reaction to sensory information:

• No startling at noises
• High or low sense of smell, taste, hearing, sight, or touch
• Normal noises may seem painful which evolves holding hands over ears
• Withdraws from contact as they might seem overstimulating
• Licks objects and rubs mouths or surfaces
• Low or high reaction to pain

Playing:

• Cannot imitate the activity of other people
•  Ritualistic or solitary play
• Inability for imaginative play

Behavior:

• Stuck on a task or topic
• Short span of attention
• Narrow interests
• Repeated body movements
• Passive or overactive
• May be aggressive to self or others
• Need for sameness