What Are the Signs of Down Syndrome?

There are some common traits, but no two people are the same

Mother holding baby with down syndrome
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Down syndrome is a common chromosomal abnormality caused by an extra copy of chromosome 21. According to the Centers for Disease Control and Prevention, approximately one in 700 people are born with Down syndrome. 

While children with Down syndrome do have recognizable features and common medical problems, it is important to remember that most children with Down syndrome are healthy.

Their risk of developing certain medical, intellectual and psychological problems may be higher, but the treatment is usually the same for these problems whether they occur in children with Down syndrome or those without Down syndrome.

It is impossible to say what Down syndrome symptoms will mean for any one individual, there are some general physical features, medical problems, and developmental delays that affect most people with Down syndrome.

Characteristics Common Among Those With Down Syndrome

To date, over 120 separate physical, medical, and psychological features have been described in people with Down syndrome. All infants and people with Down syndrome have some characteristic facial features, physical features, medical problems, and cognitive delays in common.

The features and medical problems associated with Down syndrome vary widely. Some common characteristics include: 

  • Short stature 
  • Intellectual disability 
  • Developmental delays 
  • Heart defects 
  • Thyroid problems 
  • Webbed neck and fingers 

Kids with Down syndrome tend to share certain facial and physical features such as a flat facial profile, an upward slant to the eyes, small ears, and a large or protruding tongue. At birth, infants with Down syndrome often appear “floppy” due to a condition called hypotonia (low muscle tone).

Though hypotonia can and often does improve with age and physical therapy, most children with Down syndrome typically reach developmental milestones—like sitting up, crawling, and walking—later than other kids.

At birth, kids with Down syndrome are usually of average size, but they tend to grow at a slower rate and remain smaller than other children their age. For infants, low muscle tone may contribute to feeding problems and motor delays. Toddlers and older kids may have delays in speech and in learning skills such as feeding, dressing, and toilet training.

Intellectual Disability

All individuals with Down syndrome have some degree of intellectual disability. If your child has Down syndrome, they may learn at a slower pace or have difficulty with complex reasoning and judgment. Children with Down syndrome can and do learn, and are capable of developing skills throughout their lives. They simply reach goals at a different pace.

There is often a misconception that individuals with Down syndrome have a “static” or predetermined ability to learn. This simply is not true. Individuals with Down syndrome develop over the course of their lifetime and should be treated accordingly. The learning potential of an individual with Down syndrome can be maximized through early intervention, good education, higher expectations, and encouragement.

Medical Problems

While most children with Down syndrome have no significant medical problems, others may experience a variety of medical issues that require extra care. For example, about 40 percent of all children born with Down syndrome will have a congenital heart defect. Some of these defects are mild and require no treatment and others are more severe and may require surgery and medical management. However, remember that if 40 percent of children with Down syndrome are born with heart defects, that means that 60 percent of children with Down syndrome do not have heart problems.

Other medical conditions that may occur more frequently in kids with Down syndrome include thyroid problems, intestinal abnormalities, seizure disorders, respiratory problems, weight issues, and a slightly higher risk of childhood leukemia (about 1 percent).

Upper neck abnormalities (atlantoaxial instability) are sometimes found and should be evaluated by a physician. Fortunately, many of these conditions are treatable and the treatments are the same for people with and without Down syndrome.

Hearing and Vision

Approximately half of all kids with Down syndrome also have problems with hearing and vision. Hearing loss can be due to differences in the structure of the inner ear bones or due to ear infections. Vision problems include crossed eyes, lazy eye, near and farsightedness, and an increased risk of cataracts. Regular evaluations by an audiologist and an ophthalmologist are necessary to detect and correct any problems before they affect language and learning skills. Treatments are typically glasses and hearing aids.

Personality, Behavior and Psychological Conditions

It can be hard to discuss common behavioral traits seen in people with Down syndrome without stereotyping these individuals. However, most parents with children with Down syndrome would report that their children are generally happy, sociable and outgoing. While this may generally be true, it is important not to stereotype individuals with Down syndrome. They experience a full range of emotions and have their own characteristics, strengths, weaknesses, and styles. No two people with Down syndrome will have identical personalities.

While people with Down syndrome may not have a “personality type,” they often share certain behaviors or coping mechanisms. For example, many people with Down’s syndrome prefer routine, order, and sameness which is their way of dealing with the complexities of everyday life. This preference for routine can sometimes be seen as stubbornness. Another behavior often seen in people with Down syndrome is “self-talk.” Self-talk is the act of talking aloud to oneself and it is thought that people with Down syndrome use self-talk as a way of processing information and thinking things through.

While people with Down syndrome may have some behaviors and coping mechanisms in common, they also face an increased risk for certain psychological conditions. Higher rates of anxiety disorders, depression, and obsessive-compulsive disorder have all been reported in Down syndrome. The treatment for these disorders in people with Down syndrome is the same as in people without Down syndrome and include behavior modification, counseling and possibly medication.


Stray-Gunderson, K., Babies with Down Syndrome - A New Parents Guide, Woodbine House, 1995.

Chen, H., Down syndrome, Emedicine, 2007