What Are the Signs of Down Syndrome?

A Brief Overview

Mother holding baby with down syndrome
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While Down syndrome may have a single cause—an extra chromosome 21—no two people with Down syndrome are identical. Each person with Down syndrome has their own personality, strengths, and weaknesses. While 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.

Keeping Things in Perspective

Down syndrome is not a rare condition, and it has been well-described and well-studied. To date, over 120 separate physical, medical, and psychological features have been described in people with Down syndrome. It is important to remember that no one person with Down syndrome will have all of the features described and many of the features are inconsequential to the health of the person. For example, a significant number of people with Down syndrome (about 60 percent) have a short-curved small finger—a condition called clinodactyly. While this is interesting, it does not affect how the hand of a person with Down syndrome works. It is merely one of the many features that have been described and can be seen in people with Down syndrome.

The purpose of listing some of the features seen in people with Down syndrome is not to scare or overwhelm, but to enable you to be proactive in caring for your child.

By knowing what you might expect, you can take the steps necessary to get the right treatments and support if your child does start to show any concerning signs or symptoms.

Characteristics and Treatment

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 kids with Down syndrome need a lot of medical attention, while others lead healthy lives. While there are treatments for the medical conditions sometimes faced, there is no cure for Down syndrome. Most of the medical problems seen in individuals with Down syndrome are also seen in other people. That is, the medical problems are not specific to Down syndrome, they just occur more frequently in people with Down syndrome.

How Down Syndrome Affects People

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. They learn more slowly and have difficulty with complex reasoning and judgment, but they do have the capacity to learn. For example, children with Down syndrome are often delayed in reaching developmental milestones such as walking or talking. While they tend to do so later than other children, children with Down syndrome will learn to walk and talk.

It is important to remember that it is impossible to predict the degree of intellectual disability in an infant with Down syndrome at birth (just as it is impossible to predict the IQ of any infant at birth).

Learning Potential

Down syndrome affects a child's ability to learn in different ways, but most have mild to moderate intellectual impairment. 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. It is now known that 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

Many older studies describe a ”Down’s syndrome personality.” However, this limited view is falling out of favor as more becomes known about Down syndrome. 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 - behavior modification, counseling and possibly medication.

Bottom Line

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.


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

Chen, H., Down syndrome, Emedicine, 2007

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