Cerebral palsy affects far more than movement. While it begins as damage to the developing brain, its effects ripple outward into muscle control, speech, sensation, digestion, bone health, and pain processing. About 1 in 345 children in the United States have cerebral palsy, making it the most common motor disability in childhood. The specific areas of the body affected, and how severely, depend on which parts of the brain were injured and how extensively.
Movement and Muscle Control
The most visible effect of cerebral palsy is on how the body moves. The brain injury disrupts signals between the brain and muscles, which can change muscle tone in two opposite directions. Some people develop increased muscle tone, making their bodies feel stiff or rigid. Others have decreased tone, making their muscles feel loose and floppy. Many people with CP experience both patterns in different parts of the body.
The specific movement problems fall into three main categories. Spastic cerebral palsy, the most common type, causes stiff muscles and exaggerated reflexes. It can affect one side of the body (causing weakness or paralysis in one arm and sometimes the leg), mainly the legs (creating a scissor-like walking pattern that often requires a walker or braces), or all four limbs in the most severe form, where children rarely walk independently.
Dyskinetic cerebral palsy produces slow, uncontrollable writhing or jerky movements in the hands, feet, arms, or legs. The muscles of the tongue and face can also be overactive, causing grimacing or drooling. Sitting upright and walking are difficult. Ataxic cerebral palsy, the least common type, disrupts balance, depth perception, and coordination. People with this form walk unsteadily with a wide stance and struggle with precise movements like writing or buttoning a shirt.
Hand Function and Daily Tasks
Cerebral palsy frequently affects the ability to use the hands for everyday activities: eating, dressing, writing, using a phone. Clinicians rate hand function on a five-level scale based on how independently a child can handle objects and whether they need adapted tools or physical help. For some children, the limitation is mild, maybe slower handwriting or difficulty with small buttons. For others, grasping and releasing objects requires constant effort or assistance.
This matters enormously in practical terms. A child’s ability to feed themselves, participate in school tasks, and eventually manage personal care all depend on hand function. Occupational therapy focused on hand skills is one of the most common interventions in CP for this reason.
Speech and Swallowing
The same muscle control problems that affect the limbs also affect the mouth, tongue, throat, and face. Roughly 85% of preschool children with CP have some degree of difficulty with swallowing, and the specific problems are widespread: about 70% have trouble biting and cleaning food from their mouths, 65% struggle with chewing, and 60% have difficulty sipping from a cup.
Speech is often affected as well. When the muscles needed to form words don’t respond reliably, speech can sound slurred, breathy, or effortful. In dyskinetic CP, overactive facial and tongue muscles make clear speech especially challenging. Some people with CP communicate fluently through speech, while others rely partly or entirely on communication devices.
Digestion and Nutrition
Gastrointestinal problems are frequent in people with cerebral palsy. The three most common are difficulty moving food through the mouth and throat, gastroesophageal reflux (stomach acid flowing back into the esophagus), and constipation. These issues compound each other: when swallowing is difficult and reflux causes discomfort, eating becomes stressful, and nutritional intake drops. Children with CP are at higher risk for poor growth and malnutrition as a result.
For children who take seizure medications, the situation can be further complicated. These drugs sometimes reduce alertness during meals and cause their own digestive side effects, including nausea, vomiting, and constipation. When oral feeding can’t meet a child’s nutritional needs safely, tube feeding through the stomach wall becomes an option. In severe cases involving reflux that doesn’t respond to treatment, feeding can be delivered directly past the stomach into the small intestine.
Bone and Joint Health
Over time, the abnormal muscle forces in cerebral palsy reshape the skeleton. Tight muscles pull constantly on growing bones, leading to several predictable complications. Hip displacement is one of the most closely monitored: spastic muscles around the hip can gradually pull the thigh bone out of its socket, sometimes requiring surgery ranging from soft tissue releases to bone reconstruction. The risk is highest in children with more severe movement limitations.
Scoliosis, or curvature of the spine, develops in many people with CP, particularly those who use wheelchairs. Unlike the scoliosis seen in otherwise healthy teenagers, the curves in CP tend to progress rapidly, and bracing is ineffective. Surgical spinal fusion is typically needed to stop progression. Reduced weight-bearing and physical activity also contribute to lower bone density, increasing fracture risk.
Sensory Processing and Pain
Cerebral palsy is often thought of as purely a motor condition, but the brain injuries involved also disrupt sensory pathways. Neuroimaging studies show significant damage to the white matter fibers that connect to the brain’s sensory areas, not just its motor areas. As a result, many people with CP have reduced ability to distinguish textures by touch, recognize objects by feel, and sense where their body is in space.
Paradoxically, this reduced touch sensitivity is linked to increased pain sensitivity. Research suggests that abnormal sensory experiences early in life cause long-term changes in how the brain processes pain signals. Chronic pain is now recognized as an important factor in CP, affecting quality of life in ways that were historically overlooked. Pain can come from spastic muscles, joint problems, reflux, or the nervous system itself.
Epilepsy and Intellectual Disability
Brain injury severe enough to cause cerebral palsy often affects areas beyond motor and sensory function. About 18% of people with CP have epilepsy, though the rate varies significantly depending on the type and severity of CP. Seizures can range from brief staring episodes to full convulsions.
Intellectual disability occurs in roughly 58% of people with CP, but this number masks enormous variation. Many people with CP have average or above-average intelligence, particularly those with milder physical involvement. Others, especially those with the most severe motor limitations, have significant cognitive challenges. It’s important to recognize that communication difficulties can make cognitive ability hard to assess accurately. A child who can’t speak or control their hand movements well enough to point may understand far more than they can express.
Vision and Hearing
About 23% of people with cerebral palsy have vision disorders, and roughly 17% have hearing problems. Vision issues can include difficulty controlling eye movements, reduced visual acuity, and problems with how the brain interprets what the eyes see. This last category, sometimes called cortical visual impairment, means the eyes themselves may work fine but the brain struggles to process the images.
Hearing loss in CP can stem from the same type of brain injury that caused the motor problems, from infections that occurred around birth, or from medications used during intensive neonatal care. Even mild hearing loss in a child already facing communication challenges from motor difficulties can significantly slow language development, making early screening and intervention particularly valuable.
How Severity Varies
One of the most important things to understand about cerebral palsy is how widely it varies. Clinicians use a five-level classification system for gross motor function. At the mildest end, a person walks independently with only minor limitations. In the middle levels, people use walkers, canes, or powered wheelchairs to get around. At the most severe level, all mobility is assisted, often in a manual wheelchair pushed by someone else.
A person at the mild end may deal primarily with tight muscles on one side, some hand coordination challenges, and occasional pain, while living independently and working without accommodations. Someone at the severe end may need full support for mobility, eating, communication, and personal care, while also managing seizures, reflux, hip displacement, and chronic pain. Both have cerebral palsy, but their daily experiences are vastly different. The condition is best understood not as a single diagnosis but as a spectrum shaped by which brain areas were damaged, how extensively, and how early.