Hypotonia, or low muscle tone, is common in children and can be caused by neurological conditions that affect the brain, spinal cord, nerves, or muscles. Signs of hypotonia include poor head control, slipping through caregiver's hands when held, and lying in an inverted "U" shape when placed prone or held upright. The diagnosis involves assessing prenatal risk factors, family history, signs and symptoms, and ruling out disorders of the brain, spinal cord, peripheral nerves, muscles or neuromuscular junction through examination of reflexes and extra features present. Hypotonia can be caused by various conditions like cerebral palsy, brain malformations, genetic disorders or hypoxic ischemic encephalopathy.