X-rays can confirm and distinguish possibilities of existing causes of pain that are unrelated to tennis elbow, such as fracture or arthritis. Rarely, calcification can be found where the extensor muscles attach to the lateral epicondyle. Medical ultrasonography and magnetic resonance imaging (MRI) are other valuable tools for diagnosis but are frequently avoided due to the high cost. MRI screening can confirm excess fluid and swelling in the affected region in the elbow, such as the connecting point between the forearm bone and the extensor carpi radialis brevis.

To diagnose tennis elbow, physicians perform a battery of tests in which they place pressure on the affected area while asking the patient to move the elbow, wrist, and fingers. Diagnosis is made by clinical signs and symptoms that are discrete and characteristic. For example, when the elbow fully extended, the patient feels points of tenderness over the affected point on the elbow. The most common location of tenderness is at the origin of the extensor carpi radialis brevis muscle from the lateral epicondyle (extensor carpi radialis brevis origin), 1cm distal and slightly anterior to the lateral epicondyle. There is also pain with passive wrist flexion and resistive wrist extension (Cozen's test).

Ultrasound imaging can be used to evaluate tissue strain, as well as other mechanical properties.

Ultrasound-based techniques are becoming more popular because of its affordability, safety, and speed. Ultrasound can be used for imaging tissues, and the sound waves can also provide information about the mechanical state of the tissue.

Increased water content and disorganized collagen matrix in tendon lesions may be detected by ultrasonography or magnetic resonance imaging.

RSIs are assessed using a number of objective clinical measures. These include effort-based tests such as grip and pinch strength, diagnostic tests such as Finkelstein's test for De Quervain's tendinitis, Phalen's Contortion, Tinel's Percussion for carpal tunnel syndrome, and nerve conduction velocity tests that show nerve compression in the wrist. Various imaging techniques can also be used to show nerve compression such as x-ray for the wrist, and MRI for the thoracic outlet and cervico-brachial areas.

Non-specific treatments include:

- Non-steroidal anti-inflammatory drugs (NSAIDs): ibuprofen, naproxen or aspirin

- Heat or ice

- A counter-force brace or "elbow strap" to reduce strain at the elbow epicondyle, to limit pain provocation and to protect against further damage.

Before anesthetics and steroids are used, conservative treatment with an occupational therapist may be attempted. Before therapy can commence, treatment such as the common rest, ice, compression and elevation (R.I.C.E.) will typically be used. This will help to decrease the pain and inflammation; rest will alleviate discomfort because golfer's elbow is an overuse injury. The patient can use a tennis elbow splint for compression. A pad can be placed anteromedially on the proximal forearm. The splint is made in 30–45 degrees of elbow flexion. A daytime elbow pad also may be useful, by limiting additional trauma to the nerve.

Therapy will include a variety of exercises for muscle/tendon reconditioning, starting with stretching and gradual strengthening of the flexor-pronator muscles. Strengthening will slowly begin with isometrics and progresses to eccentric exercises helping to extend the range of motion back to where it once was. After the strengthening exercises, it is common for the patient to ice the area.

Simple analgesic medication has a place, as does more specific treatment with oral anti-inflammatory medications (NSAIDs). These will help control pain and any inflammation. A more invasive treatment is the injection into and around the inflamed and tender area of a long-acting glucocorticoid (steroid) agent. After causing an initial exacerbation of symptoms lasting 24 to 48 hours, this may produce an improvement of the condition in some five to seven days.

The ulnar nerve runs in the groove between the medial humeral epicondyle and the olecranon process of the ulna. It is most important that this nerve should not be damaged accidentally in the process of injecting a golfer's elbow.

If all else fails, epicondylar debridement (a surgery) may be effective. The ulnar nerve may also be decompressed surgically.

If the appropriate remediation steps are taken - rest, ice, and rehabilitative exercise and stretching - recovery may follow. Few patients will need to progress to steroid injection, and less than 10% will require surgical intervention.

Percutaneous ultrasonic tenotomy provided continued pain relief and functional improvement for recalcitrant tennis elbow at a 3-year follow-up.

Steroid injections are helpful in the short term (first approximately 4 weeks) however, their long term effectiveness is not known, and quality of evidence for its use remains poor and controversial.

Other, more conservative and non-surgical, treatment options available for the management and treatment of tendinopathy include: rest, ice, massage therapy, eccentric exercise, NSAIDs, ultrasound therapy, LIPUS, electrotherapy, taping, sclerosing injections, blood injection, glyceryl trinitrate patches, and (ESWT) extracorporeal shockwave therapy. Studies with a rat model of fatigue-damaged tendons suggested that delaying exercise until after the initial inflammatory stage of repair could promote remodelling more rapidly. There is insufficient evidence on the routine use of injection therapies (Autologous blood, Platelet-rich plasma, Deproteinised haemodialysate, Aprotinin, Polysulphated glycosaminoglycan, Corticosteroid, Skin derived fibroblasts etc.) for treating Achilles tendinopathy. As of 2014 there was insufficient evidence to support the use of platelet-rich therapies for treating musculoskeletal soft tissue injuries such as ligament, muscle and tendon tears and tendinopathies.

The diagnosis is based on symptoms and signs alone and objective testing is expected to be normal. This syndrome may be clinically tested by flexing the patients long finger while the patient extends the wrist and fingers. Pain is a positive finding.

The chief complaint of this disease is usually pain in the dorsal aspect of the upper forearm, and any weakness described is secondary to the pain. Tenderness to palpation occurs over the area of the radial neck. Also, the disease can be diagnosed by a positive "middle finger test", where resisted middle finger extension produces pain. Radiographic evaluation of the elbow should be performed to rule out other diagnoses.

One way to prevent this injury from occurring is to be informed and educated about the risks involved in hurting your wrist and hand. If patients do suffer from median nerve palsy, occupational therapy or wearing a splint can help reduce the pain and further damage. Wearing a dynamic splint, which pulls the thumb into opposition, will help prevent an excess in deformity. This splint can also assist in function and help the fingers flex towards the thumb. Stretching and the use of C-splints can also assist in prevention of further damage and deformity. These two methods can help in the degree of movement the thumb can have. While it is impossible to prevent trauma to your arms and wrist, patients can reduce the amount of compression by maintaining proper form during repetitive activities. Furthermore, strengthening and increasing flexibility reduces the risk of nerve compression.

Tendon injury and resulting tendinopathy are responsible for up to 30% of consultations to sports doctors and other musculoskeletal health providers. Tendinopathy is most often seen in tendons of athletes either before or after an injury but is becoming more common in non-athletes and sedentary populations. For example, the majority of patients with Achilles tendinopathy in a general population-based study did not associate their condition with a sporting activity. In another study the population incidence of Achilles tendinopathy increased sixfold from 1979-1986 to 1987-1994. The incidence of rotator cuff tendinopathy ranges from 0.3% to 5.5% and annual prevalence from 0.5% to 7.4%.

Because lesions to different areas of the median nerve produce similar symptoms, clinicians perform a complete motor and sensory diagnosis along the nerve course. Decreased values of nerve conduction studies are used as indicators of nerve compression and may aid in determining the localization of compression.

Palpation above the elbow joint may reveal a bony consistency. Radiography images may show an abnormal bony spur outgrowth (supracondyloid process) just proximal to the elbow joint. Attached fibrous tissue (Struthers' ligament) may compress the median nerve as it passes underneath the process. This is also known as supracondylar process syndrome. Compression at this point may also occur without the bony spur; in this case, aponeurotic tissue found at the location of where Struthers' ligament should be is responsible for the compression.

If patients mention reproduction of symptoms to the forearm during elbow flexion of 120–130 degrees with the forearm in maximal supination, then the lesion may be localized to the area underneath the lacertus fibrosus (also known as bicipital aponeurosis). This is sometimes misdiagnosed as elbow strain and medial or lateral epicondylitis.

A lesion to the upper arm area, just proximal to where motor branches of forearm flexors originate, is diagnosed if the patient is unable to make a fist. More specifically, the patient's index and middle finger cannot flex at the MCP joint, while the thumb usually is unable to oppose. This is known as hand of benediction or Pope’s blessing hand. Another test is the bottle sign—the patient is unable to close all their fingers around a cylindrical object.

Carpal tunnel syndrome (CTS) is caused by compression of the median nerve as it passes under the carpal tunnel. Nerve conduction velocity tests through the hand are used to diagnosis CTS. Physical diagnostic tests include the Phalen maneuver or Phalen test and Tinel's sign. To relieve symptoms, patients may describe a motion similar to "shaking a thermometer", another indication of CTS.

Pronator teres syndrome (also known as pronator syndrome) is compression of the median nerve between the two heads of the pronator teres muscle. The Pronator teres test is an indication of the syndrome—the patient reports pain when attempting to pronate the forearm against resistance while extending the elbow simultaneously. The physician may notice an enlarged pronator teres muscle. Tinel's sign the area around the pronator teres heads should be positive. The key to discerning this syndrome from carpal tunnel syndrome is the absence of pain while sleeping. More recent literature collectively diagnose median nerve palsy occurring from the elbow to the forearm as pronator teres syndrome.

In uncooperative patients, the skin wrinkle test offers a pain-free way to identify denervation of the fingers. After submersion in water for 5 minutes, normal fingers will become wrinkled, whereas denervated fingers will not.

In "Ape hand deformity", the thenar muscles become paralyzed due to impingement and are subsequently flattened. This hand deformity is not by itself an individual diagnosis; it is seen only after the thenar muscles have atrophied. While the adductor pollicis remains intact, the flattening of the muscles causes the thumb to become adducted and laterally rotated. The opponens pollicis causes the thumb to flex and rotate medially, leaving the thumb unable to oppose. Carpal tunnel syndrome can result in thenar muscle paralysis which can then lead to ape hand deformity if left untreated. Ape hand deformity can also be seen in the hand of benediction deformity.

The Anterior Interosseus Nerve (AIN), a branch of the median nerve, only accounts for the movement of the fingers in hand and does not have any sensory capabilities. Therefore, the AIN syndrome is purely neuropathic. AINS is considered as an extremely rare condition because it accounts for less than 1% of neuropathies in the upper limb. Patients suffering from this syndrome have impaired distal interphalangeal joint, because of which they are unable to pinch anything or make and "OK" sign with their index finger and thumb. The syndrome can either happen from pinched nerve, or even dislocation of the elbow.

The condition is called "Golfer's Elbow" because in making a golf swing this tendon is stressed, especially if a non-overlapping (baseball style) grip is used; many people, however, who develop the condition have never handled a golf club. It is also sometimes called "Pitcher's Elbow" due to the same tendon being stressed by the throwing of objects such as a baseball, but this usage is much less frequent. Other names are "Climber's Elbow" and "Little League Elbow": all of the flexors of the fingers and the pronators of the forearm insert at the medial epicondyle of the humerus to include: pronator teres, flexor carpi radialis, flexor carpi ulnaris, flexor digitorum superficialis, and palmaris longus; making this the most common elbow injury for rock climbers, whose sport is very grip intensive. The pain is normally caused due to stress on the tendon as a result of the large amount of grip exerted by the digits and torsion of the wrist which is caused by the use and action of the cluster of muscles on the condyle of the ulna.

Epicondylitis is much more common on the lateral side of the elbow (tennis elbow), rather than the medial side. In most cases, its onset is gradual and symptoms often persist for weeks before patients seek care. In golfer's elbow, pain at the medial epicondyle is aggravated by resisted wrist flexion and pronation, which is used to aid diagnosis. On the other hand, tennis elbow is indicated by the presence of lateral epicondylar pain precipitated by resisted wrist extension. Although the condition is poorly understood at a cellular and molecular level, there are hypotheses that point to apoptosis and autophagic cell death as causes of chronic lateral epicondylitis. The cell death may decrease the muscle density and cause a snowball effect in muscle weakness - this susceptibility can compromise a muscle's ability to maintain its integrity. So athletes, like pitchers, must work on preventing this cell death via flexibility training and other preventive measures.

"Any finger injury that is sustained by a young adolescent (12–16) should be seen by a physician and have x-rays performed. These skeletally immature athletes are very susceptible to developing debilitating joint arthritis later in adulthood."

The most-often prescribed treatments for early-stage RSIs include analgesics, myofeedback, biofeedback, physical therapy, relaxation, and ultrasound therapy. Low-grade RSIs can sometimes resolve themselves if treatments begin shortly after the onset of symptoms. However, some RSIs may require more aggressive intervention including surgery and can persist for years.

General exercise has been shown to decrease the risk of developing RSI. Doctors sometimes recommend that RSI sufferers engage in specific strengthening exercises, for example to improve sitting posture, reduce excessive kyphosis, and potentially thoracic outlet syndrome. Modifications of posture and arm use (human factors and ergonomics) are often recommended.

Climbers often develop calluses on their fingers from regular contact with the rock and the rope. When calluses split open they expose a raw layer of skin that can be very painful. This type of injury is commonly referred to as a flapper.

The use of magnesium carbonate (chalk) for better grip dries out the skin and can often lead to cracked and damaged hands

There are a number of skincare products available for climbers that help to treat calluses, moisturise dry hands and reduce recovery time.

Radial Tunnel Syndrome is caused by increased pressure on the radial nerve as it travels from the upper arm (the brachial plexus) to the hand and wrist.

Prevention of MSDs relies upon identification of risk factors, either by self-report, observation on the job, or measurement of posture which could lead to MSDs. Once risk factors have been determined, there are several intervention methods which could be used to prevent the development of MSDs. The target of MSD prevention efforts is often the workplace in order to identify incidence rates of both disorders and exposure to unsafe conditions.

Assessment of MSDs are based on self-reports of symptoms and pain as well as physical examination by a doctor. Doctors rely on medical history, recreational and occupational hazards, intensity of pain, a physical exam to locate the source of the pain, and sometimes lab tests, x-rays, or an MRI Doctors look for specific criteria to diagnose each different musculoskeletal disorder, based on location, type, and intensity of pain, as well as what kind of restricted or painful movement a patient is experiencing. A popular measure of MSDs is the Nordic Questionnaire that has a picture of the body with various areas labeled and asks the individual to indicate in which areas they have experienced pain, and in which areas has the pain interfered with normal activity.

Nintendo thumb, also known as gamer's grip, Nintendonitis and similar names, is a video game-related health problem classified as a form of repetitive strain injury (RSI). The symptoms are the blistering, paraesthesia and swelling of the thumbs, mainly through use of the D-pad, though any finger can be affected. This can lead to stress on tendons, nerves and ligaments in the hands, and further onto lateral epicondylitis ("tennis elbow"), tendinitis, bursitis and carpal tunnel syndrome (CTS).

Some of the symptoms are described under trigger finger.

Originally known in a video gaming context as "Leather Thumb", this condition was known to occur frequently among users of 2nd generation video game consoles such as the Intellivision or the Atari 2600 in the late 1970s and early 1980s. The condition was first highlighted when the Nintendo games consoles were released, leading to reported cases of RSI, primarily in children (being one of the primary audiences of early-generation videogames). Later, the controllers for the Sony PlayStation and PlayStation 2 were noted as causing the condition. However, due to the shape, size and extended use of game controllers it is not limited to just those specific ones and can occur in users of any gamepad or joystick. Similar problems have also been observed with the use of mobile phones, and text messaging in particular (see Blackberry thumb).