The main symptom is pain, causing loss of ability and often stiffness. "Pain" is generally described as a sharp ache or a burning sensation in the associated muscles and tendons, and is typically made worse by prolonged activity and relieved by rest. Stiffness is most common in the morning, and typically lasts less than thirty minutes after beginning daily activities, but may return after periods of inactivity. Osteoarthritis can cause a crackling noise (called "crepitus") when the affected joint is moved or touched and people may experience muscle spasms and contractions in the tendons. Occasionally, the joints may also be filled with fluid. Some people report increased pain associated with cold temperature, high humidity, or a drop in barometric pressure, but studies have had mixed results.

Osteoarthritis commonly affects the hands, feet, spine, and the large weight-bearing joints, such as the hips and knees, although in theory, any joint in the body can be affected. As osteoarthritis progresses, movement patterns (such as gait), are typically affected. Osteoarthritis is the most common cause of a joint effusion of the knee.

In smaller joints, such as at the fingers, hard bony enlargements, called Heberden's nodes (on the distal interphalangeal joints) or Bouchard's nodes (on the proximal interphalangeal joints), may form, and though they are not necessarily painful, they do limit the movement of the fingers significantly. Osteoarthritis of the toes may be a factor causing formation of bunions, rendering them red or swollen.

Osteoarthritis (OA) is a type of joint disease that results from breakdown of joint cartilage and underlying bone. The most common symptoms are joint pain and stiffness. Initially, symptoms may occur only following exercise, but over time may become constant. Other symptoms may include joint swelling, decreased range of motion, and when the back is affected weakness or numbness of the arms and legs. The most commonly involved joints are those near the ends of the fingers, at the base of the thumb, neck, lower back, knee, and hips. Joints on one side of the body are often more affected than those on the other. Usually the symptoms come on over years. It can affect work and normal daily activities. Unlike other types of arthritis, only the joints are typically affected.

Causes include previous joint injury, abnormal joint or limb development, and inherited factors. Risk is greater in those who are overweight, have one leg of a different length, and have jobs that result in high levels of joint stress. Osteoarthritis is believed to be caused by mechanical stress on the joint and low grade inflammatory processes. It develops as cartilage is lost and the underlying bone becomes affected. As pain may make it difficult to exercise, muscle loss may occur. Diagnosis is typically based on signs and symptoms, with medical imaging and other tests occasionally used to either support or rule out other problems. In contrast to rheumatoid arthritis, which is primarily an inflammatory condition, in osteoarthritis, the joints do not typically become hot or red.

Treatment includes exercise, efforts to decrease joint stress, support groups, and pain medications. Efforts to decrease joint stress include resting and the use of a cane. Weight loss may help in those who are overweight. Pain medications may include paracetamol (acetaminophen) as well as NSAIDs such as naproxen or ibuprofen. Long-term opioid use is generally discouraged due to lack of information on benefits as well as risks of addiction and other side effects. If pain interferes with normal life despite other treatments, joint replacement surgery may help. An artificial joint typically lasts 10 to 15 years.

Osteoarthritis is the most common form of arthritis affecting about 237 million (3.3%) of the population. Among those over 60 years old, about 10% of males and 18% of females are affected. It is the cause of about 2% of years lived with disability. In Australia, about 1.9 million people are affected, and in the United States, 30 to 52.5 million people are affected. It becomes more common in both sexes as people become older.

Rheumatoid arthritis (RA), is a chronic inflammatory disorder that most typically begins in the small joints in your hands and feet. However, the course can begin with other nonspecific symptoms, such as tiredness. After attacking the smaller joints of the body, RA often progresses into larger joints, such as the shoulders, elbows, hips, and knees. Symptoms include joint pain, swelling, red and puffy hands, and fatigue. RA degrades the lining of the joints and causes swelling that is painful and can lead to joint deformity in the affected joints. Rheumatoid arthritis tends to worsen over time. Though there is no permanent cure, the course of the disease can be modified so that the damage is less, the patient is more comfortable and the patient can continue to engage in and enjoy daily activities. Treatment is most effective when it is begun as early as possible, before the process of deformity is far progressed, but some relief can be offered by treatment at any stage.

Bone erosion is the loss of bone from disease processes like rheumatoid arthritis. Bone erosion is the loss of bone in a certain area, rather than a change in bone density, which is found in osteoporosis. Surprisingly, bone erosion is not found in osteoarthritis.

Petplan Australia reported that signs of arthritis in dogs and cats include stiffness, difficulty moving, lethargy, irritability, and cat or dog may lick, chew or bite at sore joints.

Dogs might exhibit signs of stiffness or soreness after rising from rest, reluctance to exercise, bunny-hopping or other abnormal gait (legs move more together when running rather than swinging alternately), lameness, pain, reluctance to stand on rear legs, jump up, or climb stairs, subluxation or dislocation of the hip joint, or wasting away of the muscle mass in the hip area. Radiographs (X-rays) often confirm the presence of hip dysplasia, but radiographic features may not be present until two years of age in some dogs. Moreover, many affected dogs do not show clinical signs, but some dogs manifest the problem before seven months of age, while others do not show it until well into adulthood.

In part this is because the underlying hip problem may be mild or severe, may be worsening or stable, and the body may be more or less able to keep the joint in repair well enough to cope. Also, different animals have different pain tolerances and different weights, and use their bodies differently, so a light dog who only walks, will have a different joint use than a more heavy or very active dog. Some dogs will have a problem early on, others may never have a real problem at all.

Eburnation describes a degenerative process of bone commonly found in patients with osteoarthritis or non-union of fractures. It is an ivory-like reaction of bone occurring at the site of cartilage erosion. Osteoarthritis is a degenerative disease of the joints characterized largely by central loss of cartilage and compensatory peripheral bone formation (osteophytes). Over time, as the cartilage wears away, bare, subchondral bone is revealed. Eburnation describes the bony sclerosis which occurs at the areas of cartilage loss.

The disorder is more common in older adults. The disease is often occult until crystal deposits are coincidentally detected and diagnosed by a pathologist in various orthopedic specimens. It may be asymptomatic, or it can be associated with osteoarthritis, or it can present as an acute or chronic inflammatory arthritis that causes pain in one or more joints. The white blood cell count is often raised.

The arthritis is usually polyarticular (i.e., it leads to an inflammation of several joints in the body), although it may begin as monoarticular (i.e., confined to just one joint). CPPD crystals tend to form within articular tissues. In theory, any joint may be affected, but statistics show that the knees are the most commonly affected joints, as well as wrists and hips.

In many instances, patients may also have signs of carpal tunnel syndrome. This condition can also be associated with Milwaukee shoulder syndrome.

Osteoarthritis is a joint disease that causes the cushion layer between one's bones, or cartilage to wear away. It is also called degenerative joint disease. Symptoms are similar to RA and develop in the same slow manner. They include pain, tenderness in the knee, stiffness when standing or walking, loss of flexibility, and grating sensations that can be heard when the knee joint is used.

Osteoarthritis in the knee begins with the gradual deterioration of cartilage. Without the protective cartilage, the bones begin to rub together, causing pain, loss of mobility, and deformity. It affects approximately 16 million people. The majority of arthritis cases involving the knee are osteoarthritic cases.

Osteoarthritis is the most common form of arthritis. It can affect both the larger and the smaller joints of the body, including the hands, wrists, feet, back, hip, and knee. The disease is essentially one acquired from daily wear and tear of the joint; however, osteoarthritis can also occur as a result of injury. In recent years, some joint or limb deformities, such as knock-knee or acetabular overcoverage or dysplasia, have also been considered as a predisposing factor for knee or hip osteoarthritis. Osteoarthritis begins in the cartilage and eventually causes the two opposing bones to erode into each other. The condition starts with minor pain during physical activity, but soon the pain can be continuous and even occur while in a state of rest. The pain can be debilitating and prevent one from doing some activities. Osteoarthritis typically affects the weight-bearing joints, such as the back, knee and hip. Unlike rheumatoid arthritis, osteoarthritis is most commonly a disease of the elderly. More than 30 percent of women have some degree of osteoarthritis by age 65. Risk factors for osteoarthritis include prior joint trauma, obesity, and a sedentary lifestyle.

The hip could have major contractions or seizures from dysplasias. The caput is not deeply and tightly held by the acetabulum. Instead of being a snug fit, it is a loose fit, or a partial fit. Secondly, the caput or acetabulum are not smooth and round, but are misshapen, causing abnormal wear and tear or friction within the joint as it moves.

The body reacts to this in several ways. First, the joint itself is continually repairing itself and laying down new cartilage. However, cartilage repair is a relatively slow process, the tissue being avascular, so the joint may suffer degradation due to the abnormal wear and tear, or may not support the body weight as intended. The joint becomes inflamed and a cycle of cartilage damage, inflammation and pain commences. This is a self-fueling process, in that the more the joint becomes damaged, the less able it is to resist further damage. The inflammation causes further damage. The bones of the joint may also develop osteoarthritis, visible on an X-ray as small outcrops of bone, which further degrade the joint. Osteoarthritis is a degenerative disease marked by the breakdown of cartilage between joints resulting in painful bone-to-bone contact.

The underlying deformity of the joint may get worse over time, or may remain static. A dog may have good X-rays and yet be in pain, or may have very poor X-rays and have no apparent pain issues. The hip condition is only one factor to determine the extent to which dysplasia is causing pain or affecting the quality of life. In mild to moderate dysplasia it is often the secondary effects of abnormal wear and tear or arthritis, rather than dysplasia itself, which is the direct causes of visible problems.

The most common initial symptom of wrist osteoarthritis is joint pain. The pain is brought on by activity and increases when there is activity after resting. Other signs and symptoms, as with any joint affected by osteoarthritis, include:

- Morning stiffness, which usually lasts less than 30 minutes. This is also present in patients with rheumatoid arthritis, but in those patients this typically lasts for more than 45 minutes.

- Swelling of the wrist.

- Crepitus (crackling), which is felt when the hand is moved passively.

- Joint locking, where the joint is fixed in an extended position.

- Joint instability.

These symptoms can lead to loss of function and less daily activity.

Some common diseases affecting/involving the cartilage are listed below.

- Osteoarthritis: The cartilage covering bones (articular cartilage) is thinned, eventually completely worn out, resulting in a "bone against bone" joint, resulting in pain and reduced mobility. Osteoarthritis is very common, affects the joints exposed to high stress and is therefore considered the result of "wear and tear" rather than a true disease. It is treated by Arthroplasty, the replacement of the joint by a synthetic joint made of titanium and teflon. Chondroitin sulfate, a monomer of the polysaccharide portion of proteoglycan, has been shown to reduce the symptoms of osteoarthritis, possibly by increasing the synthesis of the extracellular matrix.

- Achondroplasia: Reduced proliferation of chondrocytes in the epiphyseal plate of long bones during infancy and childhood, resulting in dwarfism.

- Costochondritis: Inflammation of cartilage in the ribs, causing chest pain.

- Spinal disc herniation: Asymmetrical compression of an intervertebral disc ruptures the sac-like disc, causing a herniation of its soft content. The hernia compresses the adjacent nerves and causes back pain.

- Relapsing polychondritis: a destruction, probably autoimmune, of cartilage, especially of the nose and ears, causing disfiguration. Death occurs by suffocation as the larynx loses its rigidity and collapses.

- Cartilage tumors

The symptoms of facet joint syndrome depend almost entirely on the location of the degenerated joint, the severity of the damage and the amount of pressure that is being placed on the surrounding nerve roots. It's important to note that the amount of pain a person experiences does not correlate well with the amount of degeneration that has occurred within the joint. Many people experience little or no pain while others, with the exact same amount of damage, undergo chronic pain.

Additionally, in symptomatic facet syndrome the location of the degenerated joint plays a significant role in the symptoms that are experienced. People with degenerated joints in the upper spine will often feel pain radiating throughout the upper neck and shoulders. That said, symptoms primarily manifest themselves in the lumbar spine, since the strain is highest here due to the overlying body weight and the strong mobility. Affected persons usually feel dull pain in the cervical or lumbar spine that can radiate into the buttocks and legs. Typically, the pain is worsened by stress on the facet joints, e.g. by diffraction into hollow back (retroflexion) or lateral flexion but also by prolonged standing or walking.

Pain associated with facet syndrome is often called "referred pain" because symptoms do not follow a specific nerve root pattern and the brain can have difficulty localizing the specific area of the spine that is affected. This is why patients experiencing symptomatic facet syndrome can feel pain in their shoulders, legs and even manifested in the form of headaches.

Elbow dysplasia is a condition involving multiple developmental abnormalities of the elbow-joint in the dog, specifically the growth of cartilage or the structures surrounding it. These abnormalities, known as 'primary lesions', give rise to osteoarthritic processes. Elbow dysplasia is a common condition of certain breeds of dogs.

Most primary lesions are related to osteochondrosis, which is a disease of the joint cartilage and specifically Osteochondritis dissecans (OCD or OD), the separation of a flap of cartilage on the joint surface. Other common causes of elbow dysplasia included ununited anconeal process (UAP) and fragmented or ununited medial coronoid process (FCP or FMCP).

Osteochondritis dissecans is difficult to diagnose clinically as the animal may only exhibit an unusual gait. Consequently, OCD may be masked by, or misdiagnosed as, other skeletal and joint conditions such as hip dysplasia. The problem develops in puppyhood although often subclinically, and there may be pain or stiffness, discomfort on extension, or other compensating characteristics. Diagnosis generally depends on X-rays, arthroscopy, or MRI scans. While cases of OCD of the stifle go undetected and heal spontaneously, others are exhibited in acute lameness. Surgery is recommended once the animal has been deemed lame, before then non-surgical control is usually used.

Chondrocalcinosis is calcification in hyaline and/or fibrocartilage. It can be seen on radiography.

Pain, which can vary in severity, is a common symptom in virtually all types of arthritis. Other symptoms include swelling, joint stiffness and aching around the joint(s). Arthritic disorders like lupus and rheumatoid arthritis can affect other organs in the body, leading to a variety of symptoms. Symptoms may include:

- Inability to use the hand or walk

- Stiffness, which may be worse in the morning, or after use

- Malaise and fatigue

- Weight loss

- Poor sleep

- Muscle aches and pains

- Tenderness

- Difficulty moving the joint

It is common in advanced arthritis for significant secondary changes to occur. For example, arthritic symptoms might make it difficult for a person to move around and/or exercise, which can lead to secondary effects, such as:

- Muscle weakness

- Loss of flexibility

- Decreased aerobic fitness

These changes, in addition to the primary symptoms, can have a huge impact on quality of life.

Shoulder arthritis can be one of three types of arthritis in the glenohumeral joint of the shoulder. The glenohumeral joint is a ball and socket joint, which relies on cartilage to move smoothly and to operate normally.

When monoarthritis is caused by "pseudogout" (calcium pyrophosphate deposition disease, CPPD), the inflammation usually lasts days to weeks, and involves the knees in half of all attacks. Like gout, attacks can occur spontaneously or with physical trauma or metabolic stress. Patients may feel well in between pseudogout attacks, and 5% present with pseudo-rheumatoid symptoms.

Ringbone usually occurs in the front legs but can also be in the hind legs, and is usually worse in one leg than the other. Ringbone is most often found in mature horses, especially those in intensive training.

High ringbone: The horse will have a bony growth around the pastern area, and the pastern will have less mobility. The horse will show pain when the pastern joint is moved or rotated. Early cases will have a lameness score of 1-2 out of 5, with little or no bony swelling seen, although possibly felt when compared to the opposite pastern. Lameness will worsen to a grade 2-3 on a scale of 5 as the ringbone worsens.

Low ringbone: The horse will have moderate lameness (grade 2-3), even in early cases, because of the closeness of the ringbone to the other structures in the hoof. When severe or very advanced, the bony growth will be able to be seen on the coronet.

Ringbone is exostosis (bone growth) in the pastern or coffin joint of a horse. In severe cases, the growth can encircle the bones, giving ringbone its name. It has been suggested by some authors that such a colloquial term, whilst commonly used, might be misleading and that it would be better to refer to this condition as osteoarthritis of the inter-phalangeal joints in ungulates (Rogers and Waldron, 1995: 34-35).

Ringbone can be classified by its location, with "high ringbone" occurring on the lower part of the large pastern bone or the upper part of the small pastern bone. "Low ringbone" occurs on the lower part of the small pastern bone or the upper part of the coffin bone. High ringbone is easier seen than low ringbone, as low ringbone occurs in the hoof of the horse. However, low ringbone may be seen if it becomes serious, as it creates a bony bump on the coronet of the horse.

A common cause of chondrocalcinosis is calcium pyrophosphate dihydrate crystal deposition disease (CPPD).

Excessive calcium (due to hypomagnesemia) has a potential relationship with chondrocalcinosis, and magnesium supplementation may reduce or alleviate symptoms. In some cases, arthritis from injury can cause chondrocalcinosis.

Other causes of chondrocalcinosis include:

- Hypercalcaemia, especially when caused by hyperparathyroidism

- Arthritis

- Gout

- Wilson disease

- Hemochromatosis

- Ochronosis

- Hypothyroidism

- Hyperoxalemia

- Acromegaly

- osteoarthritis

Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, also known as pseudogout and pyrophosphate arthropathy is a rheumatologic disorder with varied symptoms and signs arising from the resultant accumulation of crystals of calcium pyrophosphate dihydrate in the connective tissues. The alternative names emphasize particular aspects of the clinical or radiographic findings. The knee joint is the most commonly affected.

Wrist osteoarthritis is a group of mechanical abnormalities resulting in joint destruction, which can occur in the wrist. These abnormalities include degeneration of cartilage and hypertrophic bone changes, which can lead to pain, swelling and loss of function. Osteoarthritis of the wrist is one of the most common conditions seen by hand surgeons.

Osteoarthritis of the wrist can be idiopathic, but it is mostly seen as a post-traumatic condition. There are different types of post-traumatic osteoarthritis. Scapholunate advanced collapse (SLAC) is the most common form, followed by Scaphoid Non-union Advanced collapse (SNAC). Other post-traumatic causes such as intra-articular fractures of the distal radius or ulna can also lead to wrist osteoarthritis, but are less common.

Elbow Dysplasia is a significant genetically determined problem in many breeds of dog, often manifesting from puppyhood and continuing for life. In elbow dysplasia, the complex elbow joint suffers from a structural defect, often related to its cartilage. This initial condition, known as a "primary lesion", causes an abnormal level of wear and tear and gradual degradation of the joint, at times disabling or with chronic pain. Secondary processes such as inflammation and osteoarthritis can arise from this damage which increase the problem and add further problems of their own.

In medicine, chondropathy refers to a disease of the cartilage. It is frequently divided into 5 grades, with 0-2 defined as normal, and 3-4 defined as diseased.