Symptoms of Down Syndrome That Should Not Be Ignored
People with Down syndrome have an increased risk of certain health conditions involving the airways, ears, eyes, thyroid, digestive system and cervical spine. The table below highlights symptoms that may need medical assessment and the health problems they could indicate:
| Symptom | What It May Indicate |
| Persistent snoring, restless sleep or excessive daytime sleepiness | Obstructive sleep apnea or another sleep-related breathing problem |
| Recurrent ear infections or difficulty hearing | Hearing loss or middle-ear problems |
| Persistent constipation, abdominal pain, bloating or poor growth | Thyroid disease, coeliac disease or another gastrointestinal problem |
| Ongoing feeding difficulties or difficulty swallowing | Oral-motor difficulties, aspiration risk or a gastrointestinal problem |
| Squinting, changes in vision or difficulty seeing | Refractive error, strabismus, cataracts or another eye condition |
| New neck pain, stiffness, head tilt or unusual head positioning | Possible cervical-spine or spinal cord involvement |
| New difficulty walking, weakness or changes in the use of the arms or hands | Possible neurological or cervical-spine involvement |
These symptoms do not necessarily mean that a person has developed a serious complication. However, new, persistent or worsening symptoms should be discussed with a healthcare professional.
Why Do Down Syndrome Symptoms Occur?
Down syndrome occurs when a person has extra genetic material from chromosome 21. This can affect how the brain and body develop and may contribute to characteristic physical features, low muscle tone, developmental differences and learning difficulties.
The extra chromosome 21 material is also associated with a higher likelihood of certain health conditions. Differences in heart development can lead to congenital heart defects, while changes affecting the ears and auditory system can contribute to hearing loss. Thyroid disorders can affect energy, growth and development, while differences in the upper airway can contribute to obstructive sleep apnea.
Gastrointestinal abnormalities may cause feeding difficulties, constipation or, in some cases, intestinal obstruction. These associated conditions do not occur in every person with Down syndrome, as symptoms can vary considerably.
Symptoms of Down Syndrome That Require Immediate Medical Attention
Some symptoms may indicate a serious acute problem and require urgent medical care. Seek immediate medical attention if a person with Down syndrome develops:
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Severe difficulty breathing or signs of respiratory distress
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Blue or grey lips, face or skin
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Loss of consciousness or markedly reduced responsiveness
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A prolonged seizure or repeated seizures
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Persistent vomiting with abdominal swelling or severe abdominal pain
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Severe dehydration or inability to keep fluids down
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Sudden weakness, difficulty walking or a marked change in the use of the arms or hands
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New severe neck pain, stiffness or head tilt, particularly when accompanied by weakness or changes in movement
These symptoms do not necessarily mean that Down syndrome itself is causing the problem. They may indicate a serious associated condition or another acute medical problem requiring urgent assessment.
Symptoms of Down Syndrome Based on Type
Down syndrome has different chromosomal forms. The table below summarises how the common forms of Down syndrome may present clinically:
| Chromosomal Form | Common Features and Presentation |
| Trisomy 21 | Characteristic physical features, low muscle tone, developmental differences and learning difficulties; associated health conditions may also occur. |
| Translocation Trisomy 21 | Physical, developmental and learning features can be similar to those seen in trisomy 21 because extra chromosome 21 material is present. |
| Mosaic Trisomy 21 | Features can vary depending on which cells contain the extra chromosome 21 material. Some people may have fewer or less noticeable physical features, while developmental or health-related differences can still occur. |
Symptoms of Down Syndrome-Specific Conditions
The table below summarises common symptoms associated with health conditions that may occur alongside Down syndrome:
| Associated Condition | Common Symptoms |
| Congenital Heart Defects | Rapid breathing, difficulty feeding, poor weight gain, excessive tiredness or a bluish colour of the lips or skin. Some heart defects may have few noticeable symptoms initially. |
| Hearing and Ear Problems | Difficulty responding to sounds, delayed speech and language development, frequently asking for repetition or difficulty following conversations. Recurrent ear infections may also occur. |
| Vision Problems | Squinting, difficulty seeing clearly, changes in eye alignment or difficulty with visual tasks. Conditions such as refractive errors and cataracts may affect vision. |
| Thyroid Disorders | Tiredness, constipation, dry skin, feeling unusually cold, slowed growth or changes in weight may occur with an underactive thyroid. |
| Obstructive Sleep Apnea | Loud or persistent snoring, restless sleep, pauses in breathing during sleep, unusual sleeping positions and excessive daytime sleepiness. |
| Cervical-Spine Problems | New neck pain or stiffness, changes in walking, weakness, changes in hand use or unusual head positioning may indicate cervical-spine involvement. |
Symptoms of Down Syndrome in Children
Down syndrome is present from conception, but some physical features and developmental differences become more noticeable as a child grows. The presentation varies from child to child, and no single physical feature can confirm the diagnosis.
Common features and developmental differences in children may include:
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Low muscle tone
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Delayed motor development, such as sitting, standing or walking later than expected
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Delayed speech and language development
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Flattened facial profile and upward-slanting eyes
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Short neck and small ears
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Small hands and feet
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A single crease across the palm
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Feeding difficulties
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Learning difficulties
Children with Down syndrome may also develop associated health problems involving hearing, vision, sleep, the thyroid, heart or digestive system. Regular health assessments can help identify these conditions even when symptoms are not obvious.
Can You Have Down Syndrome Without Symptoms?
The physical features and developmental differences in people with Down syndrome can vary considerably. Some people, particularly those with mosaic trisomy 21, may have fewer or less noticeable physical characteristics.
The absence of obvious features does not rule out Down syndrome. Some associated health conditions, such as hearing loss, vision problems, thyroid disease or obstructive sleep apnea, may also be identified through routine health assessments rather than due to noticeable symptoms.
Physical features alone cannot confirm Down syndrome. After birth, chromosome analysis of a blood sample can confirm whether extra chromosome 21 material is present.
When Can Down Syndrome Symptoms Become Life-Threatening?
Down syndrome itself is not an acute medical emergency. However, some associated health conditions can become serious and may require urgent treatment. The table below explains the main serious complications of Down syndrome and why they can become dangerous:
| Life-Threatening Complication | Why It Is Serious |
| Severe breathing problems | Significant airway obstruction or a severe respiratory infection can lead to dangerously low oxygen levels and respiratory distress. |
| Acute cardiac complications | Some congenital heart defects can affect blood flow and oxygen delivery and may cause serious cardiac complications. |
| Severe gastrointestinal obstruction | Intestinal abnormalities can cause blockage, persistent vomiting, abdominal swelling, dehydration and other serious complications. |
| Spinal cord compression | Cervical-spine complications can compress the spinal cord and cause weakness, changes in gait or hand use, and other neurological problems. |
| Severe infection | A serious infection can become life-threatening when accompanied by breathing difficulty, reduced responsiveness, severe dehydration or other signs of serious illness. |
| Prolonged or repeated seizures | Seizures that are prolonged or occur repeatedly without recovery can become a medical emergency. |
How are Down Syndrome Symptoms Diagnosed?
Physical features and developmental differences may raise suspicion of Down syndrome, but they cannot confirm the diagnosis. The diagnosis is confirmed by testing for extra chromosome 21 material. The table below explains the main prenatal screening and diagnostic tests used to identify Down syndrome:
| Diagnostic Test | Purpose |
| Prenatal ultrasound | Looks for physical findings that may be associated with Down syndrome, but does not confirm the condition. |
| Maternal blood screening | Estimates the likelihood of Down syndrome and other chromosomal conditions during pregnancy. |
| Cell-free DNA screening | Analyses fetal DNA in maternal blood to estimate the likelihood of chromosome 21 abnormalities. It is a screening test, not a definitive diagnosis. |
| Chorionic villus sampling (CVS) | Tests placental cells for chromosomal abnormalities and can provide a prenatal diagnosis. |
| Amniocentesis | Tests fetal cells from amniotic fluid to confirm chromosomal abnormalities. |
| Chromosome analysis (karyotype) | Examines chromosomes in a blood sample after birth to confirm Down syndrome and identify its chromosomal form. |
Additional tests may be used after diagnosis to check for associated health conditions. These can include an echocardiogram for congenital heart defects, hearing and eye assessments, thyroid blood tests and a sleep study when obstructive sleep apnea is suspected.
FAQs
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Q1. What is the first symptom of Down syndrome?
Ans: There is no single first symptom of Down syndrome. Some babies with Down syndrome may have features such as low muscle tone, a flattened facial profile, upward-slanting eyes, a short neck or a single crease across the palm. These features vary and cannot confirm Down syndrome on their own. -
Q2. Can Down syndrome have few noticeable symptoms?
Ans: Yes, Down syndrome can have fewer or less noticeable physical features in some people. This can occur particularly in mosaic Down syndrome, although the associated developmental or health conditions can still be present. -
Q3. Which Down syndrome symptoms should never be ignored?
Ans: Down syndrome symptoms and associated health problems, such as severe breathing difficulty, persistent vomiting with abdominal swelling, new neck pain or stiffness, weakness, changes in walking or changes in the use of the arms or hands, should be assessed promptly. Persistent hearing, vision, feeding or sleep-related problems should also be evaluated.
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References
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https://www.nichd.nih.gov/health/topics/down/conditioninfo/symptoms
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https://www.cdc.gov/birth-defects/about/down-syndrome.html
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https://pmc.ncbi.nlm.nih.gov/articles/PMC8428796/
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