Overview
Head injuries are often the result of a severe blow or impact to the head or body. An object that penetrates brain tissue, such as a bullet or a broken piece of the skull, can also cause a head injury.
Mild head injuries can temporarily affect your brain cells. More serious traumatic brain injuries can lead to bruising, tissue tears, bleeding, and other physical damage to the brain. These injuries can lead to long-term complications and even death.
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Symptoms
Traumatic brain injury can have wide-ranging physical and psychological effects. Some signs or symptoms may appear immediately after the traumatic event, while others may appear days or weeks later.
Mild traumatic brain injury
The signs and symptoms of mild traumatic brain injury may include:
Physical symptoms
Headache
Nausea or vomiting
Fatigue or drowsiness
Problems with speech
Dizziness or loss of balance
Sensory symptoms
Sensory problems, such as blurred vision, ringing in the ears, a bad taste in the mouth, or changes in the ability to smell
Sensitivity to light or sound
Cognitive, behavioral, or mental symptoms
Loss of consciousness for a few seconds to a few minutes
No loss of consciousness, but a state of being dazed, confused, or disoriented
Memory or concentration problems
Mood changes or mood swings
Feeling depressed or anxious
Difficulty sleeping
Sleeping more than usual
Moderate to severe traumatic brain injuries
Moderate to severe traumatic brain injuries can include any of the signs and symptoms of mild injury, as well as these symptoms that may appear within the first hours to days after a head injury:
Physical symptoms
Loss of consciousness from several minutes to hours
Persistent headache or headache that worsens
Repeated vomiting or nausea
Convulsions or seizures
Dilation of one or both pupils of the eyes
Clear fluids draining from the nose or ears
Inability to awaken from sleep
Weakness or numbness in fingers and toes
Loss of coordination
Cognitive or mental symptoms
Profound confusion
Agitation, combativeness, or other unusual behavior
Slurred speech
Coma and other disorders of consciousness
Children's symptoms
Infants and young children with brain injuries might not be able to communicate headaches, sensory problems, confusion, and similar symptoms. In a child with traumatic brain injury, you may observe:
Change in eating or nursing habits
Unusual or easy irritability
Persistent crying and inability to be consoled
Change in ability to pay attention
Change in sleep habits
Seizures
Sad or depressed mood
Drowsiness
Loss of interest in favorite toys or activities
When to see a doctor
Always see your doctor if you or your child has received a blow to the head or body that concerns you or causes behavioral changes. Seek emergency medical care if there are any signs or symptoms of traumatic brain injury following a recent blow or other traumatic injury to the head..
The terms “mild,” “moderate,” and “severe” are used to describe the effects of the injury on brain function. Mild traumatic brain injury is still serious and requires prompt attention and accurate diagnosis.
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Cause
Head injuries are usually caused by a blow or other trauma to the head or body. The extent of damage can depend on several factors, including the nature of the wound and the force of impact.
Common events that cause head injuries include:
Falls. Falls from beds or ladders, downstairs, into bathtubs, and other falls are the most common causes of head injuries, especially in the elderly and young children.
Collisions involving vehicles. Collisions involving cars, motorbikes, or bicycles – and pedestrians involved in such accidents – are a common cause of head injuries.
Violence. Gunshot wounds, domestic violence, child abuse, and other assaults are common causes. Shaken baby syndrome is a head injury caused by vigorous shaking in a newborn.
Sports injuries. Head injuries can result from injuries associated with several sports, including football, boxing, soccer, baseball, lacrosse, skateboarding, hockey, and other high-impact sports or other harshness.. These are especially common among young people.
Explosion and other combat wounds. Explosions are a common cause of head injuries in active-duty military personnel. Although it is not yet fully understood how the damage occurs, many researchers believe that pressure waves traveling through the brain significantly disrupt brain function.
Head injuries also result from penetrating wounds, severe blows to the head from shrapnel or debris, falls, or physical contact with objects after an explosion.
Risk factors
People at highest risk of head injury include:
Children, especially infants up to 4 years old
Young adults, especially those 15 to 24 years old age
Adults 60 years of age and older
Men of any age group
Complications
Some complications can occur immediately or shortly after a head injury. Severe injuries increase the risk of increasingly serious complications.
Altered consciousness
Moderate to severe head trauma can cause lasting or permanent changes in a person's state of consciousness, awareness, or ability to react. Different states of consciousness include:
Coma.. A person in a coma will be unconscious, unaware, and unable to respond to any stimuli. This is the result of widespread damage to all parts of the brain. After a few days to a few weeks, a person may come out of a coma or enter a vegetative state.
Vegetative state.. Extensive brain damage can lead to a vegetative state. Although the person is not aware of their surroundings, they may open their eyes, make sounds, react reflexively, or move.
The vegetative state may become permanent, but individuals often progress to a minimally conscious state.
Minimal conscious state. A minimally conscious state is a state of severely impaired consciousness but with some signs of self-awareness or awareness of the surrounding environment. Sometimes it is transitioning from a coma or vegetative state to a more healing state.
Brain death. When there is no measurable activity in the brain and brain stem, it is called brain death. In a person declared brain dead, removal of the breathing apparatus will result in cessation of breathing and possibly heart failure. Brain death is considered irreversible.
Physical complications
Convulsions. Some people with head injuries will have seizures. Seizures can occur only in the early stages or many years after the injury. Recurrent seizures are called post-traumatic epilepsy.
Fluid accumulation in the brain (hydrocephalus). Cerebrospinal fluid can accumulate in the brain cavities (ventricles) in some people with head injuries, causing increased pressure and swelling in the brain.
Infections. A skull fracture or penetrating wound can tear the protective tissue layers (meninges) that surround the brain. This can allow bacteria to enter the brain and cause infection. Infection of the meninges (meningitis) can spread to the rest of the person.