Many parents are worried about autism; actually they are often the first to notice problems in their child that might lead to that diagnosis. However, some parents or physicians might be in a bit of denial, and try to downplay the symptoms for as long as they can. It is very important that children who are suspected of having an autism disorder be evaluated by a professional. Once you know your child has autism, you should identify which type of autism he or she has. With the 5 main types of autism listed below, you'll figure out what to look for and how to best help your child.

5 Main Types of Autism

There are many levels on the autism spectrum, but these are the most common types of autism that you might encounter. Keep in mind that some of these will mimic other conditions or problems, so it is always best to check with an autism expert if you are very concerned that you child may be presenting any of the following symptoms.

1. Asperger's Sndrome

In most cases, kids who have Asperger’s syndrome are diagnosed much later, usually between the ages of five and nine, and possibly even later than that. These young people often have normal intelligence and language development, but severely impaired social skills.

Symptoms: Signs of Asperger’s syndrome include poor social interactions, odd speech patterns, obsessions, few facial expressions, a lack of understanding the body language of others, obsessive routines, extreme sensitivity to certain stimuli, and limited interests. Other signs might include clumsiness and delays in motor skill development.

2. Pervasive Developmental Disorder, Not Otherwise Specified (PDD-NOS)

This refers to a series of disorders that include delays in development, including social development, communication, and the ability to use their imagination. Parents might notice a problem when their toddler is not walking, talking or developing well.

Symptoms: Children with this type of autism will have delays in stages of development, especially communication and social development. They might be confused about the world around them and have trouble understanding how it works.

3. Autistic Disorder

Children with autistic disorder have significant difficulty with communicating and relating to other people. These kids will start to show signs at a very young age, and will continue to show further signs as they grow up. Some have below-average intelligence, but many have average or above-average intelligence and are considered “high functioning.” Autism might present with other problems, such as Fragile X syndrome or epilepsy.

Symptoms: Symptoms of autistic disorder include an inability to communicate, including not meeting the eyes of others, not responding to their name, no change in pitch when they speak, and repetition of particular behaviors. They might also become fixated on certain things, like a particular part of a toy instead of the whole toy. They tend to use their peripheral vision rather than looking straight ahead at something or someone, and they might have sensory issues as well, such as problems with certain textures or sounds.

4. Rett Syndrome

This occurs almost exclusively in girls, and tends to show up at around six months of age and progress through the rest of the child’s life. Severity varies from one child to another, but typically follows a pattern of mental and physical degeneration.

Symptoms: Symptoms often begin with behavior that seems like autism, but then progresses to sleep problems, breathing difficulties, a strange gait, teeth grinding, slowed growth, seizures, and a slowing of cognitive abilities. Early onset usually happens before 18 months of age and includes delays in motor skills or loss of skills that were already mastered. Between the ages of one and four, the child begins to lose certain abilities, such as speaking and hand skills. Between the ages of four and 10 years, the child begins a physical decline. In the final stages, the physical decline can be very severe.

5. Childhood Disintegrative Disorder

This complex disorder includes numerous different aspects of a child’s development. Research suggests that the neurobiology of the brain plays a significant factor. It is also associated with seizures or medical disorders of the brain, but the rarity of the condition means that little research has been done.

Symptoms: Most children with this syndrome tend to have normal development through the age of two, but they gradually begin to lose all they have learned after this period. The loss may be gradual, but most often it happens really fast within only a few months. The transition may start with sudden changes in behavior, such as agitation, or anger, which is followed by the loss of bowel or bladder control. Children with CDD might repeat certain behaviors over and over, and it can be very hard to move from one activity to another. They lose virtually all social skills and most of self-help skills, such as feeding themselves. Even though the regression usually stops, the losses are not regained.

If you are curious to learn more about the types of autism, including symptoms and behavioral changes of the various degrees of the disorder, this video can help:  

Important Notes: If you suspect your child might have signs of autism, speak to a doctor right away. Though some doctors might say that your child is simply undergoing a minor developmental delay, be sure to watch closely for other signs that might alert you to autism. If you have further concerns, remember that a child should be examined by a professional who has experience in autism in order to get a firm diagnosis.