Down syndrome affects multiple organ systems, and screening for these is a standard part of care rather than an exception. Common associated conditions include:

Cardiac System
– Congenital heart defects occur in roughly 40-50% of babies with Down syndrome — most commonly atrioventricular septal defect (AVSD), ventricular septal defect (VSD), and patent ductus arteriosus (PDA)
– An echocardiogram is recommended for every newborn with Down syndrome, even if no symptoms are apparent, since some defects are not immediately obvious on physical exam

Endocrine System
– Congenital hypothyroidism and acquired thyroid dysfunction (both hypo- and hyperthyroidism) are more common and can affect growth and cognitive development if untreated
– Thyroid function tests are typically recommended at birth and annually thereafter

Hearing and Vision System
– Conductive hearing loss is common, often due to recurrent ear infections and structural differences in the ear canal
– Vision issues include refractive errors, strabismus (squint), and cataracts
– Routine hearing and vision screening is recommended starting in infancy

Gastrointestinal System
– Higher incidence of duodenal atresia, Hirschsprung’s disease, and celiac disease
– Some GI anomalies (like duodenal atresia) present at birth and require surgical correction; celiac disease may need screening later in childhood

Musculoskeletal System
– Hypotonia (low muscle tone) is near-universal and affects early motor milestones
– Atlantoaxial instability (looseness in the upper spine) occurs in a subset of children and is relevant if the child will be involved in contact sports or gymnastics — screening X-rays may be advised in specific cases

Hematologic System
– Increased risk of transient abnormal myelopoiesis in newborns and a higher lifetime risk of leukemia (both AML and ALL) compared to the general population, though absolute risk remains low
– Routine blood counts are part of standard follow-up

Respiratory and Immune System
– Increased susceptibility to respiratory infections
– Higher rates of obstructive sleep apnea, related to differences in airway anatomy and low muscle tone

none of these conditions are universal, and most are manageable with early detection. The standard approach is a structured follow-up schedule — cardiac evaluation at birth, thyroid checks annually, and regular pediatric, ENT, and ophthalmology review — rather than reactive treatment after symptoms appear. Not everyone with Down syndrome will present every symptom associated with it, they are at risk for developing the above mentioned conditions.