Symptoms can vary from aches or pains and local joint stiffness, to a burning that surrounds the whole joint around the inflamed tendon. In some cases, swelling occurs along with heat and redness, and there may be visible knots surrounding the joint. With this condition, the pain is usually worse during and after activity, and the tendon and joint area can become stiff the following day as muscles tighten from the movement of the tendon. Many patients report stressful situations in their life in correlation with the beginnings of pain which may contribute to the symptoms.

If the symptoms of tendinitis last for several months (6 months) or longer, it is probably tendinosis.

Tendinitis injuries are common in the upper shoulder and lower section of the elbow (including the rotator cuff attachments), and are less common in the hips and torso. Individual variation in frequency and severity of tendinitis will vary depending on the type, frequency and severity of exercise or use; for example, rock climbers tend to develop tendinitis in their fingers or elbows, swimmers in their shoulders. Achilles tendinitis is a common injury, particularly in sports that involve lunging and jumping, while Patellar tendinitis is a common among basketball and volleyball players owing to the amount of jumping and landing.

A veterinary equivalent to Achilles tendinitis is bowed tendon, tendinitis of the superficial digital tendon of the horse.

Jumper's knee (patellar tendinopathy, patellar tendinosis, patellar tendinitis) commonly occurs in athletes who are involved in jumping sports such as basketball and volleyball. Patients report anterior knee pain, often with an aching quality. The symptom onset is insidious. Rarely is a discrete injury described. Usually, involvement is infrapatellar at or near the infrapatellar pole, but it may also be suprapatellar.

Depending on the duration of symptoms, jumper's knee can be classified into 1 of 4 stages, as follows:

Stage 1 – Pain only after activity, without functional impairment

Stage 2 – Pain during and after activity, although the patient is still able to perform satisfactorily in his or her sport

Stage 3 – Prolonged pain during and after activity, with increasing difficulty in performing at a satisfactory level

Stage 4 – Complete tendon tear requiring surgical repair

It begins as inflammation in the patellar tendon where it attaches to the patella and may progress by tearing or degenerating the tendon. Patients present with an ache over the patella tendon. Most patients are between 10 and 16 years old. Magnetic resonance imaging can reveal edema (increased T2 signal intensity) in the proximal aspect of the patellar tendon.

Symptoms can vary from an ache or pain and stiffness to the local area of the tendon, or a burning that surrounds the whole joint around the affected tendon. With this condition, the pain is usually worse during and after activity, and the tendon and joint area can become stiffer the following day as swelling impinges on the movement of the tendon. Many patients report stressful situations in their life in correlation with the beginnings of pain, which may contribute to the symptoms.

Swelling in a region of micro damage or partial tear may be detected visually or by touch.

Tennis elbow or lateral epicondylitis is a condition in which the outer part of the elbow becomes sore and tender at the lateral epicondyle. The forearm muscles and tendons become damaged from repetitive overuse. This leads to pain and tenderness on the outside of the elbow.

Any activity, including playing tennis, that involves repetitive use of the extensor muscles of the forearm can cause acute or chronic tendonitis of the tendinous insertion of these muscles at the lateral epicondyle of the elbow. The condition is common in carpenters and laborers who swing a hammer or other tool with the forearm, and is similar to golfer's elbow, which affects the medial epicondyle on the inside of the elbow. Continuing activity after onset of the condition and avoiding mandatory rest may lead to permanent onset of pain and only treatable via surgery.

Bursitis commonly affects superficial bursae. These include the subacromial, prepatellar, retrocalcaneal, and pes anserinus bursae of the shoulder, knee, heel and shin, etc. (see below). Symptoms vary from localized warmth and erythema to joint pain and stiffness, to stinging pain that surrounds the joint around the inflamed bursa. In this condition, the pain usually is worse during and after activity, and then the bursa and the surrounding joint becomes stiff the next morning.

Tendinosis, sometimes called chronic tendinitis, chronic tendinopathy, or chronic tendon injury, is damage to a tendon at a cellular level (the suffix "osis" implies a pathology of chronic degeneration without inflammation). It is thought to be caused by microtears in the connective tissue in and around the tendon, leading to an increase in tendon repair cells. This may lead to reduced tensile strength, thus increasing the chance of tendon rupture. Tendinosis is often misdiagnosed as tendinitis because of the limited understanding of tendinopathies by the medical community. Classic characteristics of "tendinosis" include degenerative changes in the collagenous matrix, hypercellularity, hypervascularity, and a lack of inflammatory cells which has challenged the original misnomer "tendinitis".

Pain is often aggravated by elevation of the arm above shoulder level or by lying on the shoulder. Pain may awaken the patient from sleep. Other complaints may be stiffness, snapping, catching, or weakness of the shoulder.

Golfer's elbow, or medial epicondylitis, is tendinosis of the medial epicondyle on the inside of the elbow. It is in some ways similar to tennis elbow, which affects the outside at the lateral epicondyle.

The anterior forearm contains several muscles that are involved with flexing the digits of the hand, and flexing and pronating the wrist. The tendons of these muscles come together in a common tendinous sheath, which originates from the medial epicondyle of the humerus at the elbow joint. In response to minor injury, or sometimes for no obvious reason at all, this point of insertion becomes inflamed.

Symptoms include swelling in the elbow, which can sometimes be large enough to restrict motion. There is pain originating in the elbow joint from mild to severe which can spread to the rest of the arm.

If the bursa is infected, there also will be prominent redness and the skin will feel very warm. Another symptom would include the infected bursa possibly opening spontaneously and draining pus.

Symptoms associated with tennis elbow include, but are not limited to: radiating pain from the outside of the elbow to the forearm and wrist, pain during extension of wrist, weakness of the forearm, a painful grip while shaking hands or torquing a doorknob, and not being able to hold relatively heavy items in the hand. The pain is similar to the condition known as "golfer's elbow", but the latter occurs at the medial side of the elbow.

Trapeziometacarpal osteoarthritis, also known as carpometacarpal (CMC) osteoarthritis (OA) of the thumb or osteoarthritis at the base of the thumb, is a reparitive joint disease affecting the first carpometacarpal joint (CMC1). This joint is formed by the trapezium bone of the wrist and the first metacarpal bone of the thumb. Because of its relative instability, this joint is a frequent site for osteoarthritis. Carpometacarpal osteoarthritis (CMC OA) of the thumb occurs when the cushioning cartilage of the joint surfaces wears away, resulting in damage of the joint.

The main complaint of patients is pain. Pain at the base of the thumb occurs when moving the thumb and might eventually persist at rest. Other symptoms include stiffness, swelling and loss of strength of the thumb. Treatment options include conservative and surgical therapies.

Enthesopathies may take the form of spondyloarthropathies (joint diseases of the spine) such as ankylosing spondylitis, plantar fasciitis, and Achilles tendinitis. Enthesopathy can occur at the elbow, wrist, carpus, hip, knee, ankle, tarsus, or heel bone, among other regions. Further examples include:

- Adhesive capsulitis of shoulder

- Rotator cuff syndrome of shoulder and allied disorders

- Periarthritis of shoulder

- Scapulohumeral fibrositis

- Synovitis of hand or wrist

- Periarthritis of wrist

- Gluteal tendinitis

- Iliac crest spur

- Psoas tendinitis

- Trochanteric tendinitis

The primary and most common symptom in patients with CMC OA of the thumb is pain. Pain at the base of the thumb is mainly experienced when moving the thumb or when applying pressure with the thumb. However, in advanced stages of CMC OA, pain might persist at rest. Another prominent symptom is loss of strength of the thumb. Patients struggle to grab or hold an object due to weakening of the thumb. For example, tying a knot or holding a saucepan becomes increasingly difficult.

If patients present themselves with similar symptoms, physicians should also consider De Quervain syndrome, rheumatoid arthritis or flexor carpi radialis and flexor pollicis longus tendinopathy as a possible cause.

Typical signs of CMC OA can be observed from the outside of the hand. For example, the area near the base of the thumb can be swollen and could appear inflamed. Advanced stages of CMC OA can eventually lead to deformity of the thumb. This deformity, also called a ‘zigzag’ deformity, is characterized by a deviation of the thenar eminence towards the middle of the hand, whilst the thumb phalanges overextend. Also a grinding sound, known as crepitus, can be heard when the CMC1 joint is moved.

Patellar tendinitis (patellar tendinopathy, also known as jumper's knee), is a relatively common cause of pain in the inferior patellar region in athletes. It is common with frequent jumping and studies have shown it may be associated with stiff ankle movement and ankle sprains.

There can be several concurrent causes. Trauma, auto-immune disorders, infection and iatrogenic (medicine-related) factors can all cause bursitis. Bursitis is commonly caused by repetitive movement and excessive pressure. Shoulders, elbows and knees are the most commonly affected. Inflammation of the bursae may also be caused by other inflammatory conditions such as rheumatoid arthritis, scleroderma, systemic lupus erythematosus and gout. Immune deficiencies, including HIV and diabetes, can also cause bursitis. Infrequently, scoliosis can cause bursitis of the shoulders; however, shoulder bursitis is more commonly caused by overuse of the shoulder joint and related muscles.

Traumatic injury is another cause of bursitis. The inflammation irritates because the bursa no longer fits in the original small area between the bone and the functionary muscle or tendon. When the bone increases pressure upon the bursa, bursitis results. Sometimes the cause is unknown. It can also be associated with various other chronic systemic diseases.

A sprain is a type of acute injury which results from the stretching or tearing of a ligament. Depending on the severity of the sprain, the movement on the joint can be compromised since ligaments aid in the stability and support of joints. Sprains are commonly seen in vulnerable areas such as the wrists, knees, and ankles. They can occur from movements such as falling on an outstretched hand, or a twisting of the ankle or foot.

The severity of a sprain can also be classified:

Grade 1: Only some of the fibers in the ligament are torn, and the injured site is moderately painful and swollen. Function in the joint will be unaffected for the most part.

Grade 2: Many of the ligament fibers are torn, and pain and swelling is moderate. The functionality of the joint is compromised.

Grade 3: The soft tissue is completely torn, and functionality and strength on the joint is completely compromised. In most cases, surgery is needed to repair the damage.

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.

In medicine, an enthesopathy refers to a disorder involving the attachment of a tendon or ligament to a bone. This site of attachment is known as the entheses.

If the condition is known to be inflammatory, it can more precisely be called an enthesitis.

A strain is a type of acute injury that occurs to the muscle or tendon. Similar to sprains, it can vary in severity, from a stretching of the muscle or tendon to a complete tear of the tendon from the muscle. Some of the most common places that strains occur are in the foot, back of the leg (hamstring), or back.

De Quervain syndrome, is a tenosynovitis of the sheath or tunnel that surrounds two tendons that control movement of the thumb.

People with Joint Hypermobility Syndrome may develop other conditions caused by their unstable joints. These conditions include:

- Joint instability causing frequent sprains, tendinitis, or bursitis when doing activities that would not affect others

- Joint pain

- Early-onset osteoarthritis (as early as during teen years)

- Subluxations or dislocations, especially in the shoulder (severe limits to ability to push, pull, grasp, finger, reach, etc., is considered a disability by the US Social Security Administration)

- Knee pain

- Fatigue, even after short periods of exercise

- Back pain, prolapsed discs or spondylolisthesis

- Joints that make clicking noises (also a symptom of osteoarthritis)

- Susceptibility to whiplash

- Temporomandibular Joint Syndrome also known as TMJ

- Increased nerve compression disorders (such as carpal tunnel syndrome)

- The ability of finger locking

- Poor response to anaesthetic or pain medication

- "Growing pains" as described in children in late afternoon or night

4

Tendinopathy refers to a disease of a tendon. The clinical presentation includes tenderness on palpation and pain, often when exercising or with movement.

Three terms have evolved in the medical terminology to refer to injuries that cause tendon pain:

- Tendinitis - acute tendon injury accompanied by inflammation

- Tendinosis - chronic tendon injury with degeneration at the cellular level and no inflammation

- Paratenonitis - Inflammation of the outer layer of the tendon (paratenon) alone, whether or not the paratenon is lined by synovium

- Paratenonitis with tendinosis - Paratenonitis associated with intratendinous degeneration

- Tendinopathy - chronic tendon injury with no implication about etiology

Tendon injuries arise from a combination of intrinsic and extrinsic factors; acute tendon injuries may be predominantly caused by extrinsic factors, whereas in overuse syndromes as in the case of tendinopathy it may be caused by multifactorial combinations of both intrinsic and extrinsic factors. An example of an intrinsic factor for tendinopathies are: poor biomechanics such as limb malalignments and hyperpronation that may cause increased traction loads acting on the foot and ankle that may increase the incidence of Achilles, flexor hallucis longus muscle, and tibialis posterior muscle tendinopathies.

Those with hypermobile joints are more likely to have fibromyalgia, mitral valve prolapse, and anxiety disorders such as panic disorder.

An individual with Panner disease most commonly experiences elbow pain near the capitellum. Other symptoms include:

- Stiffness in the elbow

- Elbow swelling

- Limited range of motion

- Elbow extension limitation

- Tenderness

These symptoms worsen with physical activity such a throwing a ball or gymnastics for example. The symptoms begin unexpectedly and are often present for several days or weeks, and the symptoms tend to last even longer.