The consequences of whiplash range from mild pain for a few days (which is the case for most people), to severe disability. It seems that around 50% will have some remaining symptoms.

Alterations in resting state cerebral blood flow have been demonstrated in patients with chronic pain after whiplash injury. There is evidence for persistent inflammation in the neck in patients with chronic pain after whiplash injury.

There has long been a proposed link between whiplash injuries and the development of temporomandibular joint dysfunction (TMD). A recent review concluded that although there are contradictions in the literature, overall there is moderate evidence that TMD can occasionally follow whiplash injury, and that the incidence of this occurrence is low to moderate.

Diagnosis occurs through a patient history, head and neck examination, X-rays to rule out bone fractures and may involve the use of medical imaging to determine if there are other injuries.

The need for imaging in patients who have suffered a minor head injury is debated. A non-contrast CT of the head should be performed immediately in all those who have suffered a moderate or severe head injury, an MRI is also an option. Computed tomography (CT) has become the diagnostic modality of choice for head trauma due to its accuracy, reliability, safety, and wide availability. The changes in microcirculation, impaired auto-regulation, cerebral edema, and axonal injury start as soon as head injury occurs and manifest as clinical, biochemical, and radiological changes.

In children with uncomplicated minor head injuries the risk of intra cranial bleeding over the next year is rare at 2 cases per 1 million. In some cases transient neurological disturbances may occur, lasting minutes to hours. Malignant post traumatic cerebral swelling can develop unexpectedly in stable patients after an injury, as can post traumatic seizures. Recovery in children with neurologic deficits will vary. Children with neurologic deficits who improve daily are more likely to recover, while those who are vegetative for months are less likely to improve. Most patients without deficits have full recovery. However, persons who sustain head trauma resulting in unconsciousness for an hour or more have twice the risk of developing Alzheimer's disease later in life.

Head injury may be associated with a neck injury. Bruises on the back or neck, neck pain, or pain radiating to the arms are signs of cervical spine injury and merit spinal immobilization via application of a cervical collar and possibly a long board.If the neurological exam is normal this is reassuring. Reassessment is needed if there is a worsening headache, seizure, one sided weakness, or has persistent vomiting.

To combat overuse of Head CT Scans yielding negative intracranial hemorrhage, which unnecessarily expose patients to radiation and increase time in the hospital and cost of the visit, multiple clinical decision support rules have been developed to help clinicians weigh the option to scan a patient with a head injury. Among these are the Canadian Head CT rule, the PECARN Head Injury/Trauma Algorithm, and the New Orleans/Charity Head Injury/Trauma Rule all help clinicians make these decisions using easily obtained information and noninvasive practices.

At least 41 systems measure the severity, or grade, of a mild head injury, and there is little agreement about which is best. In an effort to simplify, the 2nd International Conference on Concussion in Sport, meeting in Prague in 2004, decided that these systems should be abandoned in favor of a 'simple' or 'complex' classification. However, the 2008 meeting in Zurich abandoned the simple versus complex terminology, although the participants did agree to keep the concept that most (80–90%) concussions resolve in a short period (7–10 days), and although the recovery time frame may be longer in children and adolescents.

In the past, the decision to allow athletes to return to participation was frequently based on the grade of concussion. However, current research and recommendations by professional organizations including the National Athletic Trainers' Association recommend against such use of these grading systems. Currently, injured athletes are prohibited from returning to play before they are symptom-free during both rest and exertion and until results of the neuropsychological tests have returned to pre-injury levels.

Three grading systems have been most widely followed: by Robert Cantu, the Colorado Medical Society, and the American Academy of Neurology. Each employs three grades, as summarized in the following table:

Prevention of MTBI involves general measures such as wearing seat belts and using airbags in cars. Older people are encouraged to reduce fall risk by keeping floors free of clutter and wearing thin, flat, shoes with hard soles that do not interfere with balance.

Protective equipment such as headgear has been found to reduce the number of concussions in athletes and improvements in the design of helmets may decrease the number and severity further. New "Head Impact Telemetry System" technology is being placed in helmets to study injury mechanisms and may generate knowledge that will potentially help reduce the risk of concussions among American Football players. Self-reported concussion rates among U-20 and elite rugby union players in Ireland are 45–48%. Half of these injuries go unreported. Changes to the rules or enforcing existing rules in sports, such as those against "head-down tackling", or "spearing", which is associated with a high injury rate, may also prevent concussions.

The diagnosis may be confirmed by an EMG examination in 5 to 7 days. The evidence of denervation will be evident. If there is no nerve conduction 72 hours after the injury, then avulsion is most likely..

The most advanced diagnostic method is MR imaging of the brachial plexus using a high Tesla MRI scanner like 1.5 T or more. MR helps aid in the assessment of the injuries in specific context of site, extent and the nerve roots involved. In addition, assessment of the cervical cord and post traumatic changes in soft tissues may also be visualised.

The International Statistical Classification of Diseases and Related Health Problems (ICD-10) and the American Psychiatric Association's "Diagnostic and Statistical Manual of Mental Disorders" have set out criteria for post-concussion syndrome (PCS) and post-concussional disorder (PCD), respectively.

The ICD-10 established a set of diagnostic criteria for PCS in 1992. In order to meet these criteria, a patient has had a head injury "usually sufficiently severe to result in loss of consciousness" and then develop at least three of the eight symptoms marked with a check mark in the table at right under "ICD-10" within four weeks.

About 38% of people who suffer a head injury with symptoms of concussion and no radiological evidence of brain lesions meet these criteria. In addition to these symptoms, people that meet the ICD-10 criteria for PCS may fear that they will have permanent brain damage, which may worsen the original symptoms. Preoccupation with the injury may be accompanied by the assumption of a "sick role" and hypochondriasis. The criteria focus on subjective symptoms and mention that neuropsychological evidence of significant impairment is not present. With their focus on psychological factors, the ICD-10 criteria support the idea that the cause of PCS is functional. Like the ICD-10, the ICD-9-CM defines PCS in terms of subjective symptoms and discusses the greater frequency of PCS in people with histories of mental disorders or a financial incentive for a diagnosis.

The DSM-IV lists criteria for diagnosis of PCD in people who have suffered a head trauma with persistent post-traumatic amnesia, loss of consciousness, or post-traumatic seizures. In addition, for a diagnosis of PCD, patients must have neuropsychological impairment as well as at least three of the symptoms marked with a check mark in the table at right under "DSM-IV". These symptoms must be present for three months after the injury and must have been absent or less severe before the injury. In addition, the patient must experience social problems as a result, and must not meet criteria for another disorder that explains the symptoms better.

Neuropsychological tests exist to measure deficits in cognitive functioning that can result from PCS. The Stroop Color Test and the 2&7 Processing Speed Test (which both detect deficits in speed of mental processing) can predict the development of cognitive problems from PCS. A test called the Rivermead Postconcussion Symptoms Questionnaire, a set of questions that measure the severity of 16 different post-concussion symptoms, can be self-administered or administered by an interviewer. Other tests that can predict the development of PCS include the Hopkins Verbal Learning A test (HVLA) and the Digit Span Forward examination. The HVLA tests verbal learning and memory by presenting a series of words and assigning points based on the number recalled, and digit span measures attention efficiency by asking the examinee to repeat back digits spoken by the tester in the same order as they are presented. In addition, neuropsychological tests may be performed to detect malingering (exaggerating or making up symptoms) .

Once taken off the field of play due to possible concussion, being unconscious, or showing the symptoms post game, getting medical advice as soon as possible is recommended. At the hospital or medical practice, the player will be under observation, if they are experiencing a headache, mild pain killers will be given. The medical professional will request that no food or drink is to be consumed until advised. They will then assess whether the player needs an x-ray, to check for any possible cervical vertebrae damage, or a computerised axial tomography (CT Scan) to check for any brain or cranium damage. With a mild head injury being sent home to take care and doing activities slower than usual, and maintaining painkillers. If symptoms of concussion don't disappear in the average of seven to ten days, then seek medical advice again as injury could be worse. In post-concussion syndrome, symptoms do not resolve for weeks, months, or years after a concussion, and may occasionally be permanent. About 10% to 20% of people have post concussion syndrome for more than a month.

The prognosis for PCS is generally considered positive, with total resolution of symptoms in many, but not all, cases. For 50% of people, post-concussion symptoms go away within a few days to several weeks after the original injury occurs. In others, symptoms may remain for three to six months, but evidence indicates that many cases are completely resolved within 6 months. The majority of symptoms are largely gone in about half of people with concussion one month after the injury, and about two thirds of people with minor head trauma are nearly symptom-free within three months. Persistent, often severe headaches are the longest lingering symptom in most cases and are the most likely symptom to never fully resolve. It is frequently stated in the literature and considered to be common knowledge that 15–30% of people with PCS have not recovered by a year after the injury, but this estimate is imprecise because it is based on studies of people admitted to a hospital, the methodologies of which have been criticized. In approximately 15% of people, symptoms may persist for years or be permanent. If symptoms are not resolved by one year, they are likely to be permanent, though improvements may occur after even two or three years, or may suddenly occur after a long time without much improvement.

Older people and those who have previously suffered another head injury are likely to take longer to recover.

The way in which children cope with the injury after it occurs may have more of an impact than factors that existed prior to the injury. Children's mechanisms for dealing with their injuries may have an effect on the duration of symptoms, and parents who do not deal effectively with anxiety about children's post-injury functioning may be less able to help their children recover.

If another blow to the head occurs after a concussion but before its symptoms have gone away, there is a slight risk of developing the serious second-impact syndrome (SIS). In SIS, the brain rapidly swells, greatly increasing intracranial pressure. People who have repeated mild head injuries over a prolonged period, such as boxers and Gridiron football players, are at risk for chronic traumatic encephalopathy (or the related variant dementia pugilistica), a severe, chronic disorder involving a decline in mental and physical abilities.

To minimise the risks of concussion the mild traumatic brain injury, using the method of the 6 R's. Firstly Recognising and Removing a suspected player of concussion, to stop the injury from getting worse. Secondly Refer, whether the player is either recognised or suspected with concussion they must see a medical doctor as soon as possible. 90.8% of players knew they should not continue playing when concussed. 75% of players would continue an important game even if concussed. Of those concussed, 39.1% have tried to influence medical assessment with 78.2% stating it is possible or quite easy to do so. If the player is diagnosed with concussion, they then must Rest, until all signs of concussion are gone. The player must then Recover by just returning to general activities in life, then progressing back to playing. Returning to play, must follow the Graduated Return to Play (GRTP) protocol, by having clearance from a medical professional, and no symptoms of concussion. Despite good knowledge of concussion complications, management players engage in unsafe behaviour with little difference between gender and competition grades. Information regarding symptoms and management should be available to all players, coaches, and parents. On-going education is needed to assist coaches in identifying concussion signs and symptoms. Provision of medical care should be mandatory at every level of competition.

The use of surgery to treat a Jefferson fracture is somewhat controversial. Non-surgical treatment varies depending on if the fracture is stable or unstable, defined by an intact or broken transverse ligament and degree of fracture of the anterior arch. An intact ligament requires the use of a soft or hard collar, while a ruptured ligament may require traction, a halo or surgery. The use of rigid halos can lead to intracranial infections and are often uncomfortable for individuals wearing them, and may be replaced with a more flexible alternative depending on the stability of the injured bones, but treatment of a stable injury with a halo collar can result in a full recovery. Surgical treatment of a Jefferson fracture involves fusion or fixation of the first three cervical vertebrae; fusion may occur immediately, or later during treatment in cases where non-surgical interventions are unsuccessful. A primary factor in deciding between surgical and non-surgical intervention is the degree of stability as well as the presence of damage to other cervical vertebrae.

Though a serious injury, the long-term consequences of a Jefferson's fracture are uncertain and may not impact longevity or abilities, even if untreated. Conservative treatment with an immobilization device can produce excellent long-term recovery.

The severity of brachial plexus injury is determined by the type of nerve damage. There are several different classification systems for grading the severity of nerve and brachial plexus injuries. Most systems attempt to correlate the degree of injury with symptoms, pathology and prognosis. Seddon's classification, devised in 1943, continues to be used, and is based on three main types of nerve fiber injury, and whether there is continuity of the nerve.

1. Neurapraxia: The mildest form of nerve injury. It involves an interruption of the nerve conduction without loss of continuity of the axon. Recovery takes place without wallerian degeneration.

2. Axonotmesis: Involves axonal degeneration, with loss of the relative continuity of the axon and its covering of myelin, but preservation of the connective tissue framework of the nerve (the encapsulating tissue, the epineurium and perineurium, are preserved).

3. Neurotmesis: The most severe form of nerve injury, in which the nerve is completely disrupted by contusion, traction or laceration. Not only the axon, but the encapsulating connective tissue lose their continuity. The most extreme degree of neurotmesis is transsection, although most neurotmetic injuries do not produce gross loss of continuity of the nerve but rather, internal disruption of the nerve architecture sufficient to involve perineurium and endoneurium as well as axons and their covering. It requires surgery, with unpredictable recovery.

A more recent and commonly used system described by the late Sir Sydney Sunderland, divides nerve injuries into five degrees: first degree or neurapraxia, following on from Seddon, in which the insulation around the nerve called myelin is damaged but the nerve itself is spared, and second through fifth degree, which denotes increasing severity of injury. With fifth degree injuries, the nerve is completely divided.

A radiographic evaluation using an X-ray, CT scan, or MRI can determine if there is damage to the spinal column and where it is located. X-rays are commonly available and can detect instability or misalignment of the spinal column, but do not give very detailed images and can miss injuries to the spinal cord or displacement of ligaments or disks that do not have accompanying spinal column damage. Thus when X-ray findings are normal but SCI is still suspected due to pain or SCI symptoms, CT or MRI scans are used. CT gives greater detail than X-rays, but exposes the patient to more radiation, and it still does not give images of the spinal cord or ligaments; MRI shows body structures in the greatest detail. Thus it is the standard for anyone who has neurological deficits found in SCI or is thought to have an unstable spinal column injury.

Neurological evaluations to help determine the degree of impairment are performed initially and repeatedly in the early stages of treatment; this determines the rate of improvement or deterioration and informs treatment and prognosis. The ASIA Impairment Scale outlined above is used to determine the level and severity of injury.

Jefferson fracture is often caused by an impact or load on the back of the head, and are frequently associated with diving into shallow water, impact against the roof of a vehicle and falls, and in children may occur due to falls from playground equipment. Less frequently, strong rotation of the head may also result in Jefferson fractures.

Jefferson fractures are extremely rare in children, but recovery is usually complete without surgery.

There are few disorders on the differential diagnosis for carpal tunnel syndrome. Cervical radiculopathy can be mistaken for carpal tunnel syndrome since it can also cause abnormal or painful sensations in the hands and wrist. In contrast to carpal tunnel syndrome, the symptoms of cervical radiculopathy usually begins in the neck and travels down the affected arm and may be worsened by neck movement. Electromyography and imaging of the cervical spine can help to differentiate cervical radiculopathy from carpal tunnel syndrome if the diagnosis is unclear. Carpal tunnel syndrome is sometimes applied as a label to anyone with pain, numbness, swelling, and/or burning in the radial side of the hands and/or wrists. When pain is the primary symptom, carpal tunnel syndrome is unlikely to be the source of the symptoms. As a whole, the medical community is not currently embracing or accepting trigger point theories due to lack of scientific evidence supporting their effectiveness.

The first stage in the management of a suspected spinal cord injury is geared toward basic life support and preventing further injury: maintaining airway, breathing, and circulation and immobilizing the spine.

In the emergency setting, anyone who has been subjected to forces strong enough to cause SCI is treated as though they have instability in the spinal column and is immobilized to prevent damage to the spinal cord. Injuries or fractures in the head, neck, or pelvis as well as penetrating trauma near the spine and falls from heights are assumed to be associated with an unstable spinal column until it is ruled out in the hospital. High-speed vehicle crashes, sports injuries involving the head or neck, and diving injuries are other mechanisms that indicate a high SCI risk. Since head and spinal trauma frequently coexist, anyone who is unconscious or has a lowered level of consciousness as a result of a head injury is immobilized.

A rigid cervical collar is applied to the neck, and the head is held immobile with blocks on either side and the person is strapped to a backboard. Extrication devices are used to move people without moving the spine if they are still inside a vehicle or other confined space.

Modern trauma care includes a step called clearing the cervical spine, ruling out spinal cord injury if the patient is fully conscious and not under the influence of drugs or alcohol, displays no neurological deficits, has no pain in the middle of the neck and no other painful injuries that could distract from neck pain. If these are all absent, no immobilization is necessary.

If an unstable spinal column injury is moved, damage may occur to the spinal cord. Between 3 and 25% of SCIs occur not at the time of the initial trauma but later during treatment or transport. While some of this is due to the nature of the injury itself, particularly in the case of multiple or massive trauma, some of it reflects the failure to immobilize the spine adequately.

SCI can impair the body's ability to keep warm, so warming blankets may be needed.

Facet syndrome can typically be diagnosed through a physical examination, MRI, x-rays and/or a diagnostic block into the suspected joint.

Facet syndrome has no specific code in ICD-10. It can be diagnosed as “other” in M53.8 – other specified dorsopathies.

Because there are various causes for back injuries, prevention must be comprehensive. Back injuries are predominant in manual labor so the majority low back pain prevention methods have been applied primarily toward biomechanics Prevention must come from multiple sources such as education, proper body mechanics, and physical fitness.

Although widely used, the presence of a positive Phalen test, Tinel sign, Flick sign, or upper limb nerve test alone is not sufficient for diagnosis.

- Phalen's maneuver is performed by flexing the wrist gently as far as possible, then holding this position and awaiting symptoms. A positive test is one that results in numbness in the median nerve distribution when holding the wrist in acute flexion position within 60 seconds. The quicker the numbness starts, the more advanced the condition. Phalen's sign is defined as pain and/or paresthesias in the median-innervated fingers with one minute of wrist flexion. Only this test has been shown to correlate with CTS severity when studied prospectively. The test characteristics of Phalen's maneuver have varied across studies ranging from 42–85% sensitivity and 54–98% specificity.

- Tinel's sign is a classic test to detect median nerve irritation. Tinel's sign is performed by lightly tapping the skin over the flexor retinaculum to elicit a sensation of tingling or "pins and needles" in the median nerve distribution. Tinel's sign (pain and/or paresthesias of the median-innervated fingers with percussion over the median nerve), depending on the study, has 38–100% sensitivity and 55–100% specificity for the diagnosis of CTS.

- Durkan test, "carpal compression test", or applying firm pressure to the palm over the nerve for up to 30 seconds to elicit symptoms has also been proposed.

- Hand elevation test The hand elevation test is performed by lifting both hands above the head, and if symptoms are reproduced in the median nerve distribution within 2 minutes, considered positive. The hand elevation test has higher sensitivity and specificity than Tinel's test, Phalen's test, and carpal compression test. Chi-square statistical analysis has shown the hand elevation test to be as effective, if not better than, Tinel's test, Phalen's test, and carpal compression test.

As a note, a patient with true carpal tunnel syndrome (entrapment of the median nerve within the carpal tunnel) will not have any sensory loss over the thenar eminence (bulge of muscles in the palm of hand and at the base of the thumb). This is because the palmar branch of the median nerve, which innervates that area of the palm, branches off of the median nerve and passes over the carpal tunnel. This feature of the median nerve can help separate carpal tunnel syndrome from thoracic outlet syndrome, or pronator teres syndrome.

Other conditions may also be misdiagnosed as carpal tunnel syndrome. Thus, if history and physical examination suggest CTS, patients will sometimes be tested electrodiagnostically with nerve conduction studies and electromyography. The role of confirmatory nerve conduction studies is controversial. The goal of electrodiagnostic testing is to compare the speed of conduction in the median nerve with conduction in other nerves supplying the hand. When the median nerve is compressed, as in CTS, it will conduct more slowly than normal and more slowly than other nerves. There are many electrodiagnostic tests used to make a diagnosis of CTS, but the most sensitive, specific, and reliable test is the Combined Sensory Index (also known as the Robinson index). Electrodiagnosis rests upon demonstrating impaired median nerve conduction across the carpal tunnel in context of normal conduction elsewhere. Compression results in damage to the myelin sheath and manifests as delayed latencies and slowed conduction velocities However, normal electrodiagnostic studies do not preclude the presence of carpal tunnel syndrome, as a threshold of nerve injury must be reached before study results become abnormal and cut-off values for abnormality are variable. Carpal tunnel syndrome with normal electrodiagnostic tests is very, very mild at worst.

The role of MRI or ultrasound imaging in the diagnosis of carpal tunnel syndrome is unclear. Their routine use is not recommended.

A doctor will base his or her diagnosis on the symptoms the patient has and the results of tests, including:

- An X-ray

- Magnetic resonance imaging (MRI), which usually provides the most information

- Computed tomography (CT) scan

The diagnosis process might include a physician who tests that the movement, strength, and sensation of the arms and legs are normal. The spine is examined for its range of motion and any pain that may arise from movement. Blood work might be utilized in addition to radiographic imaging in order to identify spinal cord diseases. Basic imaging techniques, which includes x-ray imaging, can reveal degenerative changes of the spine, while more advanced imaging techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI), can allow visualization of more detailed anatomical structures, including that of the associated nerves and muscles. The most detailed and specific testing is electrodiagnostic, which helps to uncover whether the appropriate electrical signals are being sent to each muscle from the correlate nerves. This aids in localizing a problem's source. There are risks to be considered with any diagnostic testing. For example, in the case of CT imaging, there is obvious benefit over x-ray in that a more thorough picture of the anatomy is exposed, but there is a trade-off in that CT has around a 10-fold increased radiation exposure; alternatively, while MRI provides highly detailed imaging of the anatomy with the benefit of no radiation exposure to the patient, the high cost of this test must be taken into account.

The straight leg raise may be positive, as this finding has low specificity; however, it has high sensitivity. Thus the finding of a negative SLR sign is important in helping to "rule out" the possibility of a lower lumbar disc herniation. A variation is to lift the leg while the patient is sitting. However, this reduces the sensitivity of the test.

Diagnosis can be established using plain film x-rays as well as CT scan of the neck/cervical spine. Children with Down's syndrome have inherently lax ligaments making them susceptible to this condition. In select cases, these children may require pre-operative imaging to assess the risk for complications after procedures such as adenoidectomy.

There are multiple techniques used in the diagnosis of spondylosis, these are;

- Cervical Compression Test, a variant of Spurling's test, is performed by laterally flexing the patient's head and placing downward pressure on it. Neck or shoulder pain on the ipsilateral side (i.e. the side to which the head is flexed) indicates a positive result for this test. However it should be noted that a positive test result is not necessarily a positive result for spondylosis and as such additional testing is required.

- Lhermitte sign: feeling of electrical shock with patient neck flexion

- Reduced range of motion of the neck, the most frequent objective finding on physical examination

- MRI and CT scans are helpful for pain diagnosis but generally are not definitive and must be considered together with physical examinations and history.