A 2014 study classified cases into three types—epidermolysis bullosa simplex (EBS), junctional epidermolysis bullosa (JEB), and dystrophic epidermolysis bullosa (DEB) -- and reviewed their times of death. The first two types tended to die in infancy and the last in early adulthood.

Epidermolysis bullosa can be diagnosed either by a skin (punch) biopsy at the edge of a wound with immunofluorescent mapping, or via blood sample and genetic testing.

One of the biggest risks factors faced by the affected foals is susceptibility to secondary infection. Within three to eight days after birth, the foal may die from infection or is euthanized for welfare reasons.

Biopsies of the skin may be performed to identify the cleavage that takes place at the dermal-epidermal junction. Another test that can aid in a diagnosis of JEB is the positive Nikolsky’s sign. By applying pressure to the skin, transverse movements can indicate slipping between the dermal and epidermal layers. An easier and more definitive test is through polymerase chain reaction (PCR). This method allows mane and tail samples to be genetically tested for the mutated genes that cause the condition. Hair samples must be pulled, not cut, with roots attached. The test can detect both JEB1 and JEB2. Testing costs around $35.00 US per sample.

In 2015, an Italian team of scientists, led by Michele De Luca at the University of Modena, successfully treated a seven-year-old Syrian boy who had lost 80% of his skin. The boy's family had fled Syria for Germany in 2013. Upon seeking treatment in Germany, he had lost the epidermis from almost his entire body, with only his head and a patch on his left leg remaining. The group of Italian scientists had previously pioneered a technique to regenerate healthy skin in the laboratory. They used this treatment on the boy by taking a sample from his remaining healthy skin and then genetically modifying the skin cells, using a virus to deliver a healthy version of the LAMB3 gene into the nuclei. The patient underwent two operations in autumn 2015, where the new epidermis was attached. The graft had integrated into the lower layers of skin within a month, curing the boy. The introduction of genetic changes could increase the chances of skin cancer in other patients, but if the treatment is deemed safe in the long term, scientists believe the approach could be used to treat other skin disorders.

These include:

- "Generalized atrophic benign epidermolysis bullosa" is a skin condition that is characterized by onset at birth, generalized blisters and atrophy, mucosal involvement, and thickened, dystrophic, or absent nails.

- "Mitis junctional epidermolysis bullosa" (also known as "Nonlethal junctional epidermolysis bullosa") is a skin condition characterized by scalp and nail lesions, also associated with periorificial nonhealing erosions. Mitis junctional epidermolysis bullosa is most commonly seen in children between the ages of 4 and 10 years old.

- "Cicatricial junctional epidermolysis bullosa" is a skin condition characterized by blisters that heal with scarring. It was characterized in 1985.

Genetic testing and counselling are available to help determine the risk of passing the condition onto a child. This may involve testing a sample of tissue or blood to look for signs of the genetic mutation that causes haemophilia.

A pregnant woman with a history of haemophilia in her family can test for the haemophilia gene. Such tests include:

- chorionic villus sampling (CVS) – a small sample of the placenta is removed from the womb and tested for the haemophilia gene, usually during weeks 11-14 of pregnancy

- amniocentesis – a sample of amniotic fluid is taken for testing, usually during weeks 15-20 of pregnancy

There's a small risk of these procedures causing problems such as miscarriage or premature labour, so the woman may discuss this with the doctor in charge of her care.

Platinosis is an allergy-like reaction to exposure to soluble salts of platinum.

The symptoms of platinosis may include asthma, dermatitis, dyspnea, conjunctival vasodilatation, and rhinopharyngitis.

The symptoms are progressive, sometimes taking months to years to appear. Platinosis is usually associated with workers in industries related to platinum production.

The effects are permanent.

Halogeno-platinum compounds are among the most potent respiratory and skin sensitisers known, therefore it is vital that exposure via the skin and by breathing contaminated air is carefully controlled.

In practice, the compounds mainly responsible for platinum sensitisation are typically the soluble, ionic, platinum-chloro compounds such as ammonium hexachloroplatinate and tetrachloroplatinate, and hexachloroplatinic acid. Other ionic halogeno compounds are also sensitisers, the order of allergenicity being Cl > Br > I.

Neutral compounds such as "cis"-platin and ammine and nitro complexes such as [Pt(NH)]Cl, K[Pt(NO)] and platinum nitrate are not considered to be allergenic; neither is the metal.

Diagnosis of age-related macular degeneration rests on signs in the macula, irrespective of visual acuity. Diagnosis of AMD may include the following procedures and tests:

- The transition from dry to wet AMD can happen rapidly, and if it is left untreated can lead to legal blindness in as little as six months. To prevent this from occurring and to initiate preventative strategies earlier in the disease process, dark adaptation testing may be performed. A dark adaptometer can detect subclinical AMD at least three years earlier than it is clinically evident.

- There is a loss of contrast sensitivity, so that contours, shadows, and color vision are less vivid. The loss in contrast sensitivity can be quickly and easily measured by a contrast sensitivity test like Pelli Robson performed either at home or by an eye specialist.

- When viewing an Amsler grid, some straight lines appear wavy and some patches appear blank

- When viewing a Snellen chart, at least 2 lines decline

- Preferential hyperacuity perimetry changes (for wet AMD)

- In dry macular degeneration, which occurs in 85–90 percent of AMD cases, drusen spots can be seen in Fundus photography

- In wet macular degeneration, angiography can visualize the leakage of bloodstream behind the macula. Fluorescein angiography allows for the identification and localization of abnormal vascular processes.

- Using an electroretinogram, points in the macula with a weak or absent response compared to a normal eye may be found

- Farnsworth-Munsell 100 hue test and Maximum Color Contrast Sensitivity test (MCCS) for assessing color acuity and color contrast sensitivity

- Optical coherence tomography is now used by most ophthalmologists in the diagnosis and the follow-up evaluation of the response to treatment with antiangiogenic drugs.

A practical application of AMD-associated genetic markers is in the prediction of progression of AMD from early stages of the disease to neovascularization.

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.

Medical personnel aim to determine whether a seizure is caused by a change in the patient's biochemistry, such as hyponatremia. Neurological examinations and tests to measure levels of serum electrolytes are performed.

Not all seizures that occur after trauma are PTS; they may be due to a seizure disorder that already existed, which may even have caused the trauma. In addition, post-traumatic seizures are not to be confused with concussive convulsions, which may immediately follow a concussion but which are not actually seizures and are not a predictive factor for epilepsy.

Neuroimaging is used to guide treatment. Often, MRI is performed in any patient with PTS, but the less sensitive but more easily accessed CT scan may also be used.

Seizures that result from TBI are often difficult to treat. Antiepileptic drugs that may be given intravenously shortly after injury include phenytoin, sodium valproate, carbamazepine, and phenobarbital. Antiepileptic drugs do not prevent all seizures in all people, but phenytoin and sodium valproate usually stop seizures that are in progress.

Diagnosis is suspected based on lesion circumstances and clinical evidence, most prominently a neurological examination, for example checking whether the pupils constrict normally in response to light and assigning a Glasgow Coma Score. Neuroimaging helps in determining the diagnosis and prognosis and in deciding what treatments to give.

The preferred radiologic test in the emergency setting is computed tomography (CT): it is quick, accurate, and widely available. Follow-up CT scans may be performed later to determine whether the injury has progressed.

Magnetic resonance imaging (MRI) can show more detail than CT, and can add information about expected outcome in the long term. It is more useful than CT for detecting injury characteristics such as diffuse axonal injury in the longer term. However, MRI is not used in the emergency setting for reasons including its relative inefficacy in detecting bleeds and fractures, its lengthy acquisition of images, the inaccessibility of the patient in the machine, and its incompatibility with metal items used in emergency care. A variant of MRI since 2012 is High definition fiber tracking (HDFT).

Other techniques may be used to confirm a particular diagnosis. X-rays are still used for head trauma, but evidence suggests they are not useful; head injuries are either so mild that they do not need imaging or severe enough to merit the more accurate CT. Angiography may be used to detect blood vessel pathology when risk factors such as penetrating head trauma are involved. Functional imaging can measure cerebral blood flow or metabolism, inferring neuronal activity in specific regions and potentially helping to predict outcome. Electroencephalography and transcranial doppler may also be used. The most sensitive physical measure to date is the quantitative EEG, which has documented an 80% to 100% ability in discriminating between normal and traumatic brain-injured subjects.

Neuropsychological assessment can be performed to evaluate the long-term cognitive sequelae and to aid in the planning of the rehabilitation. Instruments range from short measures of general mental functioning to complete batteries formed of different domain-specific tests.

CT scan (computed tomography) is the definitive tool for accurate diagnosis of an intracranial hemorrhage. In difficult cases, a 3T-MRI scan can also be used.

When ICP is increased the heart rate may be decreased.

It is not known whether PTS increase the likelihood of developing PTE. Early PTS, while not necessarily epileptic in nature, are associated with a higher risk of PTE. However, PTS do not indicate that development of epilepsy is certain to occur, and it is difficult to isolate PTS from severity of injury as a factor in PTE development. About 3% of patients with no early seizures develop late PTE; this number is 25% in those who do have early PTS, and the distinction is greater if other risk factors for developing PTE are excluded. Seizures that occur immediately after an insult are commonly believed not to confer an increased risk of recurring seizures, but evidence from at least one study has suggested that both immediate and early seizures may be risk factors for late seizures. Early seizures may be less of a predictor for PTE in children; while as many as a third of adults with early seizures develop PTE, the portion of children with early PTS who have late seizures is less than one fifth in children and may be as low as one tenth. The incidence of late seizures is about half that in adults with comparable injuries.

A "subarachnoid hemorrhage" is bleeding into the subarachnoid space—the area between the arachnoid membrane and the pia mater surrounding the brain. Besides from head injury, it may occur spontaneously, usually from a ruptured cerebral aneurysm. Symptoms of SAH include a severe headache with a rapid onset ("thunderclap headache"), vomiting, confusion or a lowered level of consciousness, and sometimes seizures. The diagnosis is generally confirmed with a CT scan of the head, or occasionally by lumbar puncture. Treatment is by prompt neurosurgery or radiologically guided interventions with medications and other treatments to help prevent recurrence of the bleeding and complications. Since the 1990s, many aneurysms are treated by a minimal invasive procedure called "coiling", which is carried out by instrumentation through large blood vessels. However, this procedure has higher recurrence rates than the more invasive craniotomy with clipping.

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.

Head trauma recipients are initially assessed to exclude a more severe emergency such as an intracranial hemorrhage. This includes the "ABCs" (airway, breathing, circulation) and stabilization of the cervical spine which is assumed to be injured in any athlete who is found to be unconscious after head or neck injury. Indications that screening for more serious injury is needed include worsening of symptoms such as headache, persistent vomiting, increasing disorientation or a deteriorating level of consciousness, seizures, and unequal pupil size. Those with such symptoms, or those who are at higher risk for a more serious brain injury, may undergo brain imaging to detect lesions and are frequently observed for 24–48 hours. A brain CT or brain MRI should be avoided unless there are progressive neurological symptoms, focal neurological findings or concern of skull fracture on exam.

Diagnosis of MTBI is based on physical and neurological examination findings, duration of unconsciousness (usually less than 30 minutes) and post-traumatic amnesia (PTA; usually less than 24 hours), and the Glasgow Coma Scale (MTBI sufferers have scores of 13 to 15). Neuropsychological tests exist to measure cognitive function and the international consensus meeting in Zurich recommended the use of the SCAT2 test.

If the Glasgow Coma Scale is less than 15 at two hours, or less than 14 at any time, a CT is recommended. In addition, a CT scan is more likely to be performed if observation after discharge is not assured or intoxication is present, there is suspected increased risk for bleeding, age greater than 60, or less than 16. Most concussions, without complication, cannot be detected with MRI or CT scans. However, changes have been reported on MRI and SPECT imaging in those with concussion and normal CT scans, and post-concussion syndrome may be associated with abnormalities visible on SPECT and PET scans. Mild head injury may or may not produce abnormal EEG readings.

Concussion may be under-diagnosed because of the lack of the highly noticeable signs and symptoms while athletes may minimize their injuries to remain in the competition. A retrospective survey in 2005 suggested that more than 88% of concussions are unrecognized.

Diagnosis can be complex because concussion shares symptoms with other conditions. For example, post-concussion symptoms such as cognitive problems may be misattributed to brain injury when, in fact, due to post-traumatic stress disorder (PTSD).

The diagnosis of hepatic encephalopathy can only be made in the presence of confirmed liver disease (types A and C) or a portosystemic shunt (type B), as its symptoms are similar to those encountered in other encephalopathies. To make the distinction, abnormal liver function tests and/or ultrasound suggesting liver disease are required, and ideally liver biopsy. The symptoms of hepatic encephalopathy may also arise from other conditions, such as cerebral haemorrhage and seizures (both of which are more common in chronic liver disease). A CT scan of the brain may be required to exclude haemorrhage, and if seizure activity is suspected an electroencephalograph (EEG) study may be performed. Rarer mimics of encephalopathy are meningitis, encephalitis, Wernicke's encephalopathy and Wilson's disease; these may be suspected on clinical grounds and confirmed with investigations.

The diagnosis of hepatic encephalopathy is a clinical one, once other causes for confusion or coma have been excluded; no test fully diagnoses or excludes it. Serum ammonia levels are elevated in 90% of people, but not all hyperammonaemia (high ammonia levels) is associated with encephalopathy. A CT scan of the brain usually shows no abnormality except in stage IV encephalopathy, when cerebral oedema may be visible. Other neuroimaging modalities, such as magnetic resonance imaging (MRI), are not currently regarded as useful, although they may show abnormalities. Electroencephalography shows no clear abnormalities in stage 0, even if minimal HE is present; in stages I, II and III there are triphasic waves over the frontal lobes that oscillate at 5 Hz, and in stage IV there is slow delta wave activity. However, the changes in EEG are not typical enough to be useful in distinguishing hepatic encephalopathy from other conditions.

Once the diagnosis of encephalopathy has been made, efforts are made to exclude underlying causes (such as listed above in "causes"). This requires blood tests (urea and electrolytes, full blood count, liver function tests), usually a chest X-ray, and urinalysis. If there is ascites, diagnostic paracentesis (removal of a fluid sample with a needle) may be required to identify spontaneous bacterial peritonitis (SBP).

In those with cirrhosis, the risk of developing hepatic encephalopathy is 20% per year, and at any time about 30–45% of people with cirrhosis exhibit evidence of overt encephalopathy. The prevalence of minimal hepatic encephalopathy detectable on formal neuropsychological testing is 60–80%; this increases the likelihood of developing overt encephalopathy in the future. Once hepatic encephalopathy has developed, the prognosis is determined largely by other markers of liver failure, such as the levels of albumin (a protein produced by the liver), the prothrombin time (a test of coagulation, which relies on proteins produced in the liver), the presence of ascites and the level of bilirubin (a breakdown product of hemoglobin which is conjugated and excreted by the liver). Together with the severity of encephalopathy, these markers have been incorporated into the Child-Pugh score; this score determines the one- and two-year survival and may assist in a decision to offer liver transplantation.

In acute liver failure, the development of severe encephalopathy strongly predicts short-term mortality, and is almost as important as the nature of the underlying cause of the liver failure in determining the prognosis. Historically, widely used criteria for offering liver transplantation, such as King's College Criteria, are of limited use and recent guidelines discourage excessive reliance on these criteria. The occurrence of hepatic encephalopathy in people with Wilson's disease (hereditary copper accumulation) and mushroom poisoning indicates an urgent need for a liver transplant.

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:

TBI is a leading cause of death and disability around the globe and presents a major worldwide social, economic, and health problem. It is the number one cause of coma, it plays the leading role in disability due to trauma, and is the leading cause of brain damage in children and young adults. In Europe it is responsible for more years of disability than any other cause. It also plays a significant role in half of trauma deaths.

Findings on the frequency of each level of severity vary based on the definitions and methods used in studies. A World Health Organization study estimated that between 70 and 90% of head injuries that receive treatment are mild, and a US study found that moderate and severe injuries each account for 10% of TBIs, with the rest mild.

The incidence of TBI varies by age, gender, region and other factors. Findings of incidence and prevalence in epidemiological studies vary based on such factors as which grades of severity are included, whether deaths are included, whether the study is restricted to hospitalized people, and the study's location. The annual incidence of mild TBI is difficult to determine but may be 100–600 people per 100,000.

In renal compensation, plasma bicarbonate rises 3.5 mEq/L for each increase of 10 mm Hg in "Pa"CO. The expected change in serum bicarbonate concentration in respiratory acidosis can be estimated as follows:

- Acute respiratory acidosis: HCO increases 1 mEq/L for each 10 mm Hg rise in "Pa"CO.

- Chronic respiratory acidosis: HCO rises 3.5 mEq/L for each 10 mm Hg rise in "Pa"CO.

The expected change in pH with respiratory acidosis can be estimated with the following equations:

- Acute respiratory acidosis: Change in pH = 0.008 X (40 − "Pa"CO)

- Chronic respiratory acidosis: Change in pH = 0.003 X (40 − "Pa"CO)

Respiratory acidosis does not have a great effect on electrolyte levels. Some small effects occur on calcium and potassium levels. Acidosis decreases binding of calcium to albumin and tends to increase serum ionized calcium levels. In addition, acidemia causes an extracellular shift of potassium, but respiratory acidosis rarely causes clinically significant hyperkalemia.

Respiratory acidosis is a medical emergency in which decreased ventilation (hypoventilation) increases the concentration of carbon dioxide in the blood and decreases the blood's pH (a condition generally called acidosis).

Carbon dioxide is produced continuously as the body's cells respire, and this CO will accumulate rapidly if the lungs do not adequately expel it through alveolar ventilation. Alveolar hypoventilation thus leads to an increased "Pa"CO (a condition called hypercapnia). The increase in "Pa"CO in turn decreases the HCO/"Pa"CO ratio and decreases pH.