Cerebral Palsy represents a group of conditions and no two people with CP have the exact same symptoms. The primary symptom is abnormal muscle tone resulting in uncoordinated gross and fine motor skills. Reflexes, balance and posture are adversely affected. If there is poor facial tone, swallowing and talking may be impaired. Seizures may be the first presenting symptom in the newborn period and usually represent a severe brain injury.

Since infants and young children cannot communicate, doctors and parents rely on clinical signs to make a diagnosis of CP. There are eight clinical signs which are abnormal muscle tone, uncoordinated movement, persistent fetal reflexes, asymmetric posture, balance control issues, fine motor skills, gross motor skills like walking, and vocal or oral dysfunction which impairs speech or swallowing.

Multiple interacting and dependent muscles are needed to perform various physical activities. If one muscle is not working properly, then other muscles must compensate to complete a specific motion or movement. Even then, it is unlikely that the movement or activity will occur or look normal. The brain is essential to coordinate muscles and the location of the brain injury will determine the functional impairment. One of the most obvious and common signs of CP is abnormal muscle tone. Sometimes the muscles are relaxing when they should be holding tone while other muscles are always tight and cannot relax. This results in floppy or rigid muscles, respectively. Clonus is when the muscle has spasms or involuntary contractions.

The next three signs of an impairment are movement, coordination, and control which often result in limbs being extended, moving constantly, jerking with spasms, or tight and contracted. The types of coordination and control abnormalities consist of spastic movements, dyskinetic, ataxic, mixtures of one or more, and gait disturbances. Some types of gait disturbances are limping, walking on toes, walking hunched over, angling toes inward or outward, waddling, and dragging the foot.

The fifth category of signs of cerebral palsy are reflexes which are involuntary movements elicited from a stimulus. Persistence of fetal (primitive)reflexes or abnormal responses are warning signs for CP. They are asymmetrical tonic reflex, symmetrical tonic neck reflex, the Moro (startle) reflex, tonic labyrinthine reflex, palmer grasp reflex, placing reflex, and spinal gallant reflexes. Early hand preference can indicate an impending problem.

Posture that is not symmetric can be an early sign of cerebral palsy especially if the hip joints are affected. Postural responses are the responses expected when placing the baby in certain positions. If they do not develop or are asymmetric, CP is possible. Some of the common postural responses are traction, parachute response, Landau reflex, head righting, and trunk righting.

Balance abnormalities as a result of abnormal gross motor skills can signify cerebral palsy. If a child cannot sit without support, requires both hands to sit, cannot balance when not using the hands, sways when standing still, or has difficulty with quick movements, further investigation is warranted.

The inability to use large muscle groups to coordinate movements is a sign that gross motor function is impaired. This can be due to inflexibility or abnormal tone. Common examples of gross motor function are rolling over, sitting up, walking, and standing. Sometime the function is delayed or is abnormal from the start.

Fine motor dysfunction occurs when new activities cannot be learned or executed properly. Using crayons, holding objects using the thumb and forefinger, and grasping small items are examples of fine motor function.

There are many muscles needed for proper oral motor function such as speaking, swallowing, drooling, and chewing. Coordinated movement of the lips, jaw, and tongue is complex and can be abnormal with more severe cases of CP. Thus, breathing, saying words correctly, inflating the cheeks, or licking the lips may be impaired in children with CP.