Closed head injuries sometimes, but not always, present with noticeable symptoms: following trauma to the head, symptoms may appear immediately afterwards, arise a considerable time after, or never appear at all. Closed head injuries, in contrast to open head injuries, may initially appear less significant. However, closed head injuries can be far more severe than open head injuries, even in the absence of symptoms, according to the Brain Injury Institute.
Open head injuries result when external forces throw the brain forward or backward against the skull. Although the skull never breaks or cracks, differentiating these injuries from open head injuries, damage still occurs. Upon impact, movement of the brain damages surrounding nerves. The brain may swell as well, putting pressure on cranial tissues and even tissues surrounding the eyes, causing vision impairment.
Following a blow to the head, patients may exhibit some signs of brain injury, even with a closed head injury. Symptoms can include headache, unconsciousness, short-term memory loss, dilated pupils, convulsions, slurred speech, emotional or behavioral changes and even digestive problems such as nausea and vomiting. In severe cases, brain swelling produces more significant and long-term effects, including seizures, reduced cognitive function, personality changes, abnormal sensory perception, coma and even death. Doctors treat head injuries according to severity of trauma and symptoms; treatments range from rest and medication to surgery.