According to guidelines set forth by the Space Medicine Division, all long-duration astronauts with postflight vision changes should be considered a suspected case of VIIP syndrome. Each case could then be further differentiated by definitive imaging studies establishing the postflight presence of optic-disc edema, increased ONSD and altered OCT findings. The results from these imaging studies are then divided into five classes that determine what follow-up testing and monitoring is required.

Spaceflight induced visual impairment is hypothesized to be a result of increased intracranial pressure. The study of visual changes and intracranial pressure (ICP) in astronauts on long-duration flights is a relatively recent topic of interest to Space Medicine professionals. Although reported signs and symptoms have not appeared to be severe enough to cause blindness in the near term, long term consequences of chronically elevated intracranial pressure is unknown.

NASA has reported that fifteen long-duration male astronauts (45–55 years of age) have experienced confirmed visual and anatomical changes during or after long-duration flights. Optic disc edema, globe flattening, choroidal folds, hyperopic shifts and an increased intracranial pressure have been documented in these astronauts. Some individuals experienced transient changes post-flight while others have reported persistent changes with varying degrees of severity.

Although the exact cause is not known at this time, it is suspected that microgravity-induced cephalad fluid shift and comparable physiological changes play a significant role in these changes. Other contributing factors may include pockets of increased CO and an increase in sodium intake. It seems unlikely that resistive or aerobic exercise are contributing factors, but they may be potential countermeasures to reduce intraocular pressure (IOP) or intracranial pressure (ICP) in-flight.

People with this disease have shown many sensory and muscular symptoms. Most patients have a sensory ataxia, or sensory loss in various extremities, along with mild to moderate muscle weakness, usually starting in the toes and fingers and moving inward. Most patients also present a mild to moderate tremor in the extremities which increases as the disease progresses.

More severe symptoms occur after the disease progresses and there is much more damage to the myelin sheaths in the peripheral nervous system. These can present as deabilitating tremors that prevent patients from doing normal tasks, complete sensory loss on limbs, and, in some cases, extensive muscle atrophy.

Lameness is most commonly caused by pain, but may also be the result of neuromuscular disease or mechanical restriction. Lameness itself is a clinical sign, and not a diagnosis.

Pain is the most common cause of lameness in the horse. It is usually the result of trauma or orthopedic disease, but other causes such as metabolic dysfunction, circulatory disease, and infection can also cause pain and subsequent lameness.

Orthopedic causes of lameness are very common and may be the result of damage to the hoof, bone, joints, or soft tissue. Horses are predisposed to orthopedic lameness by conformational flaws, poor hoof balance, working on poor footing, repetitive movements, poor conditioning for a given activity, and competing at a very high athletic level.

Metabolic causes of lameness include hyperkalemic periodic paralysis (HYPP) and polysaccharide storage myopathy, which directly affect muscular function.

Circulatory causes of lameness occur when blood flow to an area is compromised. This may be due to abnormal blood clotting, as in the case of aortic-iliac thrombosis, or decreased blood flow (ischemia) to an area, such as is sometimes seen in laminitis.

Infectious causes of lameness are the result of inflammation and damage to tissue. These include problems such as cellulitis, hoof abscesses, and septic arthritis.

Because many organs can be affected by myeloma, the symptoms and signs vary greatly. A mnemonic sometimes used to remember some of the common symptoms of multiple myeloma is CRAB: C = calcium (elevated), R = renal failure, A = anemia, B = bone lesions. Myeloma has many other possible symptoms, including opportunistic infections (e.g., pneumonia) and weight loss. CRAB symptoms and proliferation of monoclonal plasma cells in the bone marrow are part of the diagnostic criteria of multiple myeloma.

Some symptoms (e.g., weakness, confusion, and fatigue) may be due to anemia or hypercalcemia. Headache, visual changes, and retinopathy may be the result of hyperviscosity of the blood depending on the properties of the paraprotein. Finally, radicular pain, loss of bowel or bladder control (due to involvement of spinal cord leading to cord compression) or carpal tunnel syndrome, and other neuropathies (due to infiltration of peripheral nerves by amyloid) may occur. It may give rise to paraplegia in late-presenting cases.

When the disease is well-controlled, neurological symptoms may result from current treatments, some of which may cause peripheral neuropathy, manifesting itself as numbness or pain in the hands, feet, and lower legs.

Subglottic stenosis is a congenital or acquired narrowing of the subglottic airway. Although it is relatively rare, it is the third most common congenital airway problem (after laryngomalacia and vocal cord paralysis). Subglottic stenosis can present as a life-threatening airway emergency. It is imperative that the otolaryngologist be an expert at dealing with the diagnosis and management of this disorder. Subglottic stenosis can affect both children and adults.

Subglottic stenosis can be of three forms, namely congenital subglottic stenosis, idiopathic subglottic stenosis (ISS) and acquired subglottic stenosis. As the name suggests, congenital subglottic stenosis is a birth defect. Idiopathic subglottic stenosis is a narrowing of the airway due to an unknown cause. Acquired subglottic stenosis generally follows as an after-effect of airway intubation, and in extremely rare cases as a result of gastroesophageal reflux disease (GERD).

Subglottic stenosis is graded according to the Cotton-Meyer classification system from one to four based on the severity of the blockage.

Grade 1 – <50% obstruction

Grade 2 – 51–70% obstruction

Grade 3 – 71–99% obstruction

Grade 4 – no detectable lumen

Treatments to alleviate the symptoms of subglottic stenosis includes a daily dose of steroids such as prednisone, which reduces the inflammation of the area for better breathing. Other medications such as Methotrexate is also being tested by patients but results are pending.

The World Health Organization (WHO) developed the International Classification of External Causes of Injury (ICECI). Under this system, injuries are classified by

- mechanism of injury;

- objects/substances producing injury;

- place of occurrence;

- activity when injured;

- the role of human intent;

and additional modules. These codes allow the identification of distributions of injuries in specific populations and case identification for more detailed research on causes and preventive efforts.

The United States Bureau of Labor Statistics developed the Occupational Injury and Illness Classification System (OIICS). Under this system injuries are classified by

- nature,

- part of body affected,

- source and secondary source, and

- event or exposure.

The OIICS was first published in 1992 and has been updated several times since.

The Orchard Sports Injury Classification System (OSICS) is used to classify injuries to enable research into specific sports injuries.

Injury is damage to the body caused by external force. This may be caused by accidents, falls, hits, weapons, and other causes. Major trauma is injury that has the potential to cause prolonged disability or death.

In 2013, 4.8 million people died from injuries, up from 4.3 million in 1990. More than 30% of these deaths were transport-related injuries. In 2013, 367,000 children under the age of five died from injuries, down from 766,000 in 1990. Injuries are the cause of 9% of all deaths, and are the sixth-leading cause of death in the world.