People with diabetes mellitus are at higher risk for any kind of peripheral neuropathy, including ulnar nerve entrapments.

Cubital tunnel syndrome is more common in people who spend long periods of time with their elbows bent, such as when holding a telephone to the head. Flexing the elbow while the arm is pressed against a hard surface, such as leaning against the edge of a table, is a significant risk factor. The use of vibrating tools at work or other causes of repetitive activities increase the risk, including throwing a baseball.

Damage to or deformity of the elbow joint increases the risk of cubital tunnel syndrome. Additionally, people who have other nerve entrapments elsewhere in the arm and shoulder are at higher risk for ulnar nerve entrapment. There is some evidence that soft tissue compression of the nerve pathway in the shoulder by a bra strap over many years can cause symptoms of ulnar neuropathy, especially in very large-breasted women.

A nerve may be compressed by prolonged or repeated external force, such as sitting with one's arm over the back of a chair (radial nerve), frequently resting one's elbows on a table (ulnar nerve), or an ill-fitting cast or brace on the leg (peroneal nerve). Part of the patient's body can cause the compression and the term "entrapment neuropathy" is used particularly in this situation. The offending structure may be a well-defined lesion such as a tumour (for example a lipoma, neurofibroma or metastasis), a ganglion cyst or a haematoma. Alternatively, there may be expansion of the tissues around a nerve in a space where there is little room for this to occur, as is often the case in carpal tunnel syndrome. This may be due to weight gain or peripheral oedema (especially in pregnancy), or to a specific condition such as acromegaly, hypothyroidism or scleroderma and psoriasis.

Some conditions cause nerves to be particularly susceptible to compression. These include diabetes, in which the blood supply to the nerves is already compromised, rendering the nerve more sensitive to minor degrees of compression. The genetic condition HNPP is a much rarer cause.

The international debate regarding the relationship between CTS and repetitive motion in work is ongoing. The Occupational Safety and Health Administration (OSHA) has adopted rules and regulations regarding cumulative trauma disorders. Occupational risk factors of repetitive tasks, force, posture, and vibration have been cited.

The relationship between work and CTS is controversial; in many locations, workers diagnosed with carpal tunnel syndrome are entitled to time off and compensation.

Some speculate that carpal tunnel syndrome is provoked by repetitive movement and manipulating activities and that the exposure can be cumulative. It has also been stated that symptoms are commonly exacerbated by forceful and repetitive use of the hand and wrists in industrial occupations, but it is unclear as to whether this refers to pain (which may not be due to carpal tunnel syndrome) or the more typical numbness symptoms.

A review of available scientific data by the National Institute for Occupational Safety and Health (NIOSH) indicated that job tasks that involve highly repetitive manual acts or specific wrist postures were associated with incidents of CTS, but causation was not established, and the distinction from work-related arm pains that are not carpal tunnel syndrome was not clear. It has been proposed that repetitive use of the arm can affect the biomechanics of the upper limb or cause damage to tissues. It has also been proposed that postural and spinal assessment along with ergonomic assessments should be included in the overall determination of the condition. Addressing these factors has been found to improve comfort in some studies. A 2010 survey by NIOSH showed that 2/3 of the 5 million carpal tunnel cases in the US that year were related to work. Women have more work-related carpal tunnel syndrome than men.

Speculation that CTS is work-related is based on claims such as CTS being found mostly in the working adult population, though evidence is lacking for this. For instance, in one recent representative series of a consecutive experience, most patients were older and not working. Based on the claimed increased incidence in the workplace, arm use is implicated, but the weight of evidence suggests that this is an inherent, genetic, slowly but inevitably progressive idiopathic peripheral mononeuropathy.

In terms of the prognosis of ulnar neuropathy early decompression of the nerve sees a return to normal ability (function). which should be immediate.Severe cubital tunnel syndrome tends to have a faster recovery process in individuals below the age of 70, as opposed to those above such an age. Finally, revisional surgery for cubital tunnel syndrome does not result well for those individuals over 50 years of age.

External pressure reduces flow in the vessels supplying the nerve with blood (the vasa nervorum). This causes local ischaemia, which has an immediate effect on the ability of the nerve axons to transmit action potentials. As the compression becomes more severe over time, focal demyelination occurs, followed by axonal damage and finally scarring.

Among the causes of ulnar neuropathy are the following-

Much more commonly, ulnar neuropathy is caused by overuse of the triceps muscle and repetitive stress combined with poor ergonomics. Overused and hypertonic triceps muscle causes inflammation in the tendon and adhesions with the connective tissue surrounding that tendon and muscle. These in turn impinge on or trap the ulnar nerve. Ulnar neuropathy resulting from repetitive stress is amenable to massage and can usually be fully reversed without cortisone or surgery.

Center for Occupational and Environmental Neurology , Baltimore, MD has this to say:

“Repetitive Strain Injuries (RSI) refers to many different diagnoses of the neck/shoulder, arm, and wrist/hand area usually associated with work-related ergonomic stressors. Other terms used for Repetitive Strain Injuries are overuse syndrome, musculoskeletal disorders, and cumulative trauma disorders. Some of the more common conditions under these headings include:

Cubital Tunnel Syndrome-compression of the ulnar nerve in the cubital tunnel at the elbow.”

Anything compromising the tunnel of the posterior tibial nerve proves significant in the risk of causing TTS. Neuropathy can occur in the lower limb through many modalities, some of which include obesity and inflammation around the joints. By association, this includes risk factors such as RA, compressed shoes, pregnancy, diabetes and thyroid diseases

Most patients diagnosed with cubital tunnel syndrome have advanced disease (atrophy, static numbness, weakness) that might reflect permanent nerve damage that will not recover after surgery. When diagnosed prior to atrophy, weakness or static numbness, the disease can be arrested with treatment. Mild and intermittent symptoms often resolve spontaneously.

In terms of prognosis radial neuropathy is not necessarily permanent, though sometimes there could be partial loss of movement/sensation.Complications may be possible deformity of the hand in some individuals.

If the injury is axonal (the underlying nerve fiber itself is damaged) then full recovery may take months or years ( or could be permanent). EMG and nerve conduction studies are typically performed to diagnose the extent and distribution of the damage, and to help with prognosis for recovery.

A variety of patient factors can lead to CTS, including heredity, size of the carpal tunnel, associated local and systematic diseases, and certain habits. Non-traumatic causes generally happen over a period of time, and are not triggered by one certain event. Many of these factors are manifestations of physiologic aging.

Examples include:

- Rheumatoid arthritis and other diseases that cause inflammation of the flexor tendons.

- With hypothyroidism, generalized myxedema causes deposition of mucopolysaccharides within both the perineurium of the median nerve, as well as the tendons passing through the carpal tunnel.

- During pregnancy women experience CTS due to hormonal changes (high progesterone levels) and water retention (which swells the synovium), which are common during pregnancy.

- Previous injuries including fractures of the wrist.

- Medical disorders that lead to fluid retention or are associated with inflammation such as: inflammatory arthritis, Colles' fracture, amyloidosis, hypothyroidism, diabetes mellitus, acromegaly, and use of corticosteroids and estrogens.

- Carpal tunnel syndrome is also associated with repetitive activities of the hand and wrist, in particular with a combination of forceful and repetitive activities

- Acromegaly causes excessive secretion of growth hormones. This causes the soft tissues and bones around the carpel tunnel to grow and compress the median nerve.

- Tumors (usually benign), such as a ganglion or a lipoma, can protrude into the carpal tunnel, reducing the amount of space. This is exceedingly rare (less than 1%).

- Obesity also increases the risk of CTS: individuals classified as obese (BMI > 29) are 2.5 times more likely than slender individuals (BMI < 20) to be diagnosed with CTS.

- "Double-crush syndrome" is a debated hypothesis that compression or irritation of nerve branches contributing to the median nerve in the neck, or anywhere above the wrist, increases sensitivity of the nerve to compression in the wrist. There is little evidence, however, that this syndrome really exists.

- Heterozygous mutations in the gene SH3TC2, associated with Charcot-Marie-Tooth, confer susceptibility to neuropathy, including the carpal tunnel syndrome.

It is difficult to determine the exact cause of Tarsal Tunnel Syndrome. It is important to attempt to determine the source of the problem. Treatment and the potential outcome of the treatment may depend on the cause. Anything that creates pressure in the Tarsal Tunnel can cause TTS. This would include benign tumors or cysts, bone spurs, inflammation of the tendon sheath, nerve ganglions, or swelling from a broken or sprained ankle. Varicose veins (that may or may not be visible) can also cause compression of the nerve. TTS is more common in athletes and other active people. These people put more stress on the tarsal tunnel area. Flat feet may cause an increase in pressure in the tunnel region and this can cause nerve compression. Those with lower back problems may have symptoms. Back problems with the L4, L5 and S1 regions are suspect and might suggest a "Double Crush" issue: one "crush" (nerve pinch or entrapment) in the lower back, and the second in the tunnel area. In some cases, TTS can simply be idiopathic.

Rheumatoid Arthritis has also been associated with TTS.

The mechanism of radial neuropathy is such that it can cause focal demyelination and axonal problems/degeneration (which is nerve fiber reaction to insult, and therefore axon death occurs). These would be caused via laceration or compression of the nerve in question.

The lateral femoral cutaneous nerve most often becomes injured by entrapment or compression where it passes between the upper front hip bone (ilium) and the inguinal ligament near the attachment at the anterior superior iliac spine (the upper point of the hip bone). Less commonly, the nerve may be entrapped by other anatomical or abnormal structures, or damaged by diabetic or other neuropathy or trauma such as from seat belt injury in an accident.

The nerve may become painful over a period of time as weight gain makes underwear, belting or the waistband of pants gradually exert higher levels of pressure. Pain may be acute and radiate into the rib cage, and into the groin, thigh, and knee. Alternately, weight loss or aging may remove protective fat layers under the skin, so the nerve can compress against underwear, outer clothing, and—most commonly— by belting. Long periods of standing or leg exercise that increases tension on the inguinal ligament may also cause pressure.

The entire distribution of the nerve is rarely affected. Usually, the unpleasant sensation(s) affect only part of the skin supplied by the nerve.

The radial nerve, like any other in the nervous system, is vulnerable to damage. This damage can originate when the nerve fibers experience pressure, stretching, or cutting. All of the aforementioned issues can prevent an action potential from continuing down the nerve, which would interrupt signal transduction to and from the brain. As a result of the interrupted signal, the patient may experience loss of feeling or motor control.

There are many ways to acquire radial nerve palsy.

The term "Saturday Night Palsy" refers to an injury to the radial nerve in the spiral groove of the humerus caused while sleeping in a position that would under normal circumstances cause discomfort. It can occur when a person falls asleep while heavily medicated and/or under the influence of alcohol with the underside of the arm compressed by a bar edge, bench, chair back, or like object. Sleeping with the head resting on the arm can also cause radial nerve palsy.

Breaking the humerus and deep puncture wounds can also cause the condition.

Posterior interosseus palsy is distinguished from radial nerve palsy by the preservation of elbow extension.

Symptoms vary depending on the severity and location of the trauma; however, common symptoms include wrist drop (the inability to extend the wrist upward when the hand is palm down); numbness of the back of the hand and wrist, specifically over the first web space which is innervated by the radial nerve; and inability to voluntarily straighten the fingers or extend the thumb, which is performed by muscles of the extensor group, all of which are primarily innervated by the radial nerve. Loss of wrist extension is due to paralysis of the posterior compartment of forearm muscles; although the elbow extensors are also innervated by the radial nerve, their innervation is usually spared because the compression occurs below, distal, to the level of the axillary nerve, which innervates the long head of the triceps, and the upper branches of the radial nerve that innervate the remainder of the Triceps.

There are many possible causes of small fiber neuropathy. The most common cause is diabetes or glucose intolerance. Other possible causes include hypothyroidism, Sjögren's syndrome, Lupus, vasculitis, sarcoidosis, nutritional deficiency, Celiac disease, Lyme disease, HIV, Fabry disease, amyloidosis and alcoholism. A 2008 study reported that in approximately 40% of patients no cause could be determined after initial evaluation. When no cause can be identified, the neuropathy is called idiopathic. A recent study revealed dysfunction of a particular sodium channel (Nav1.7) in a significant portion of the patient population with an idiopathic small fiber neuropathy.

Recently several studies have suggested an association between autonomic small fiber neuropathy and postural orthostatic tachycardia syndrome. Other notable studies have shown a link between erythromelalgia, and fibromyalgia.

SFN is a common feature in adults with Ehlers-Danlos Syndrome (EDS). Skin biopsy could be considered an additional diagnostic tool to investigate pain manifestations in EDS.

There are many causes of TOS. The most frequent cause is trauma, either sudden (as in a clavicle fracture caused by a car accident), or repetitive (as in a legal secretary who works with his/her hands, wrists, and arms at a fast paced desk station with non-ergonomic posture for many years). TOS is also found in certain occupations involving lots of lifting of the arms and repetitive use of the wrists and arms.

One cause of arterial compression is trauma, and a recent case involving fracture of the clavicle has been reported.

The two groups of people most likely to develop TOS are those suffering from neck injuries due to traffic accidents and those who use computers in non-ergonomic postures for extended periods of time. TOS is frequently a repetitive stress injury (RSI) caused by certain types of work environments. Other groups which may develop TOS are athletes who frequently raise their arms above the head (such as swimmers, volleyball players, dancers, badminton players, baseball pitchers, and weightlifters), rock climbers, electricians who work long hours with their hands above their heads, and some musicians.

Peripheral Myelin Protein 22 gene encodes a 22-kD protein that comprises 2 to 5% of peripheral nervous system myelin, it is located on chromosome locus 17p12

Overlap with Charcot-Marie-Tooth disease type 1A has been found in "Gly94fsX222 (c.281_282insG)", due to point mutations of PMP 22 that occur in a minority of cases of hereditary neuropathy with liability to pressure palsy. The point mutations -missense, nonsense and splice-site have each been alluded to in HNPP.

Hereditary neuropathy with liability to pressure palsy is an autosomal dominant genetic disease (which means one parent must be affected). A mutation in one copy of the gene PMP-22 (Peripheral myelin protein 22, 17p11.2) that makes the peripheral myelin protein causes haploinsufficiency, where the activity of the normal gene is insufficient to compensate for the loss of function of the other gene.

Mononeuropathy is a type of neuropathy that only affects a single nerve. Diagnostically, it is important to distinguish it from polyneuropathy because when a single nerve is affected, it is more likely to be due to localized trauma or infection.

The most common cause of mononeuropathy is physical compression of the nerve, known as compression neuropathy. Carpal tunnel syndrome and axillary nerve palsy are examples. Direct injury to a nerve, interruption of its blood supply resulting in (ischemia), or inflammation also may cause mononeuropathy.

Anterior interosseous syndrome or Kiloh-Nevin syndrome I is a medical condition in which damage to the anterior interosseous nerve (AIN), a motor branch of the median nerve, causes pain in the forearm and a characteristic weakness of the pincer movement of the thumb and index finger.

Most cases of AIN syndrome are due to a transient neuritis, although compression of the AIN can happen. Trauma to the median nerve have also been reported as a cause of AIN syndrome.

Although there is still controversy among upper extremity surgeons, AIN syndrome is now regarded as a neuritis (inflammation of the nerve) in most cases; this is similar to Parsonage–Turner syndrome. Although the exact etiology is unknown, there is evidence that it is caused by an immune mediated response.

Studies are limited, and no randomized controlled trials have been performed regarding the treatment of AIN syndrome. While the natural history of AIN syndrome is not fully understood, studies following patients who have been treated without surgery show that symptoms can resolve starting as late as one year after onset. Other retrospective studies have shown that there is no difference in outcome in surgically versus nonsurgically treated patients. Surgical decompression is rarely indicated in AIN syndrome. Indications for considering surgery include a known space-occupying lesion that is compressing the nerve (a mass) and persistent symptoms beyond 1 year of conservative treatment.

Perioperative PION patients have a higher prevalence of cardiovascular risk factors than in the general population. Documented cardiovascular risks in people affected by perioperative PION include high blood pressure, diabetes mellitus, high levels of cholesterol in the blood, tobacco use, abnormal heart rhythms, stroke, and obesity. Men are also noted to be at higher risk, which is in accordance with the trend, as men are at higher risk of cardiovascular disease. These cardiovascular risks all interfere with adequate blood flow, and also may suggest a contributory role of defective vascular autoregulation.

Injuries of the forearm with compression of the nerve is the most common cause: examples include

supracondylar fractures, often associated with haemorrhage into the deep musculature;

injury secondary to open reduction of a forearm fracture; or dislocation of the elbow.⁠⁠

Direct trauma from a penetrating injury such as a stab wound is a common cause for the syndrome.

Fibrous bands or arcuate (curved) ligaments may entrap the median as well as the anterior interosseous nerves, in which case a patient may experience numbness as well as pain.⁠⁠

Rheumatoid disease and gouty arthritis may be a predisposing factor in anterior interosseous nerve entrapment.

Very similar syndromes can be caused by more proximal lesions, such as brachial plexus neuritis.⁠

Anterior interosseous nerve entrapment or compression injury remains a difficult clinical diagnosis because it is mainly a motor nerve and the syndrome is often mistaken for finger ligamentous injury.⁠

Small fiber peripheral neuropathy is a type of peripheral neuropathy that occurs from damage to the small unmyelinated peripheral nerve fibers. These fibers, categorized as C fibers, are present in skin, peripheral nerves, and organs. The role of these nerves is to innervate the skin ("somatic fibers") and help control autonomic function ("autonomic fibers"). It is estimated that 15-20 million people in the United States suffer from some form of peripheral neuropathy.