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What is Osteoarthritis?
Osteoarthritis is the most common form of arthritis and is diagnosed primarily in older adults.
The disease generally affects cartilage, the tough but smooth tissue that covers the ends of bones where they meet to form a joint. Healthy cartilage allows bones to glide smoothly over one another and absorbs the shock generated by physical movement. In osteoarthritis, the surface layer of cartilage breaks down and wears away. The exposed bone surfaces then rub against each other, causing:
- pain,
- swelling,
- loss of joint mobility.
The joints most frequently affected include:
- the finger joints closest to the nails,
- the thumbs,
- the neck (cervical osteoarthritis),
- the lower back,
- the knees and hips.
Osteoarthritis manifests differently from person to person. It can progress quickly, but in most cases joint damage develops gradually over time. In some patients, the disease is relatively mild and interferes only marginally with daily activities; in others, it causes severe pain and disability.
Over time, the joint may become deformed, and small bony growths called osteophytes (or bone spurs) can form along the joint margins. Small fragments of bone or cartilage may break off and move freely within the joint space, intensifying pain and causing further damage.
People with osteoarthritis typically complain of joint pain and stiffness. Unlike other forms of arthritis, such as rheumatoid arthritis, osteoarthritis affects only the joint itself, it does not involve the skin, lungs, eyes, or blood vessels.
In rheumatoid arthritis, the immune system attacks joint tissue, triggering and sustaining pain, inflammation, and, over the long term, joint damage and deformity. It typically appears in younger individuals, causing joint swelling and redness, and can also cause systemic symptoms such as malaise, fatigue, and fever. Joint involvement in rheumatoid arthritis is typically symmetrical, meaning that if one joint is affected, the same joint on the other side of the body will usually show similar symptoms. Osteoarthritis, on the other hand, can affect a single joint or both sides of the body, but often with very different degrees of severity.
Osteoarthritis or Rheumatoid Arthritis?
Osteoarthritis and rheumatoid arthritis are two conditions that share several features:
- both fall under the category of rheumatic diseases,
- both affect the joints,
- both share many symptoms (pain and stiffness above all).
Given their similar-sounding names, it is understandable that people often confuse the two terms, using them interchangeably, when in reality they represent profoundly different conditions.
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Rheumatoid arthritis is an inflammatory disease, often of autoimmune origin (caused by an abnormal activation of the immune system against the joints), and it can appear at any age.
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Osteoarthritis, by contrast, is not an inflammatory disease but rather the result of chronic joint degeneration typically associated with advancing age.
Many authors group under the umbrella term arthritis (literally meaning “joint inflammation” or “painful joint”) all diseases that affect the joints, meaning osteoarthritis would technically fall under this broader category as well (and in fact represents its most common form).
In this article, we will follow this broader terminology convention. For a more detailed overview of all forms of arthritis, please refer to our dedicated article.
Joints: A Quick Anatomy Refresher
A joint is the point where two or more bones meet. With a few exceptions (such as the skull and pelvis), joints are designed to allow movement between bones and to absorb shock generated by actions such as walking or performing repetitive movements. Mobile joints are made up of several components:
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Cartilage: a tough but slippery tissue that covers the end of each bone. In osteoarthritis, cartilage breaks down and wears away over time.
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Joint capsule: a sturdy sac that encloses all the bones and other components of the joint.
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Synovium: a thin membrane lining the inside of the joint capsule that secretes synovial fluid.
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Synovial fluid: a fluid that lubricates the joint and helps keep cartilage smooth and healthy.
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Ligaments, tendons, and muscles: tissues surrounding the bones and joints that allow them to bend and move. Ligaments are strong, rope-like bands of tissue that connect bones to each other.
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Tendons: strong, fibrous cords that connect muscles to bones. Muscles are bundles of specialized cells that contract or relax in response to nerve signals to produce movement.
Causes
Osteoarthritis is by far the most common form of arthritis, and the percentage of people affected increases with age. However, the exact cause of osteoarthritis remains unknown to this day. The most widely accepted hypothesis is that the disease has a multifactorial origin, meaning it results from the combined action of multiple contributing causes.
The extent and severity of the disease process appears to depend on the number of contributing factors involved, their intensity, and the duration of their action.
Risk Factors
Although osteoarthritis becomes more common with age, younger individuals can also develop it, typically following a joint injury, a joint malformation, or a genetic defect affecting joint cartilage.
The disease affects both men and women, though patterns differ by age:
- before age 45, it is more common in men,
- after age 45, it becomes more common in women.
Osteoarthritis is also more common in individuals who are overweight and in those who work in occupations that place repetitive stress on specific joints.
Symptoms
Osteoarthritis generally develops gradually.
In its early stages, joints may hurt after physical work or exercise; over time, joint pain tends to become more persistent. Stiffness may also develop, particularly upon waking in the morning or after remaining in the same position for an extended period.
Although osteoarthritis can affect any joint, it most commonly affects:
- the hands,
- the knees,
- the hips and spine (neck or lower back).
Symptoms can vary depending on which specific joints are affected.
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Hands: Osteoarthritis of the hands appears to have a hereditary component, meaning it tends to run in families. A woman whose mother or grandmother has or had osteoarthritis of the hands has a higher-than-average risk of developing it as well. Hand osteoarthritis is more common in women, and in many cases appears after menopause.
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Knees: The knees are among the joints most frequently affected by osteoarthritis. Symptoms include stiffness, swelling, and pain, which can make it difficult to walk, climb stairs, or get in and out of a car or bathtub. Knee osteoarthritis can lead to significant disability.
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Hips: The hips are also frequently affected by osteoarthritis. As with the knees, symptoms include joint pain and stiffness. In some cases, however, pain may be felt in the groin, inner thigh, buttocks, or even the knees. Hip osteoarthritis can limit movement and the ability to bend, making everyday activities like getting dressed or putting on shoes more difficult.
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Spine: Osteoarthritis of the spine (cervical osteoarthritis) can cause stiffness and pain in the neck or lower back. In some cases, arthritis-related changes can compress nerves at the point where they exit the spine, leading to weakness, tingling, or numbness in the arms and legs. In severe cases, it can even affect bladder and bowel function.
Diagnosis
There is no single specific test that can diagnose osteoarthritis. Instead, diagnosis is reached through a combination of steps.
Medical History
The doctor begins by asking the patient to describe their symptoms, including how and when they began and how they have progressed over time. The doctor will also review the patient’s overall medical history and that of close relatives, as well as any medications or therapies currently being used.
Physical Examination
The doctor examines reflexes and overall physical condition, including muscle strength. They will inspect the symptomatic joints and observe the patient’s ability to walk, bend, and perform daily activities.
Imaging Techniques
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X-ray: X-rays can help determine the type of arthritis and the extent of joint damage that has already occurred. X-rays of the affected joint can reveal cartilage loss, bone damage, and new bone growths (spurs or osteophytes). However, there is often a significant discrepancy between the severity of osteoarthritis seen on X-ray and the degree of pain and disability actually experienced by the patient. Additionally, X-rays cannot detect signs of the disease until cartilage loss becomes significant.
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Magnetic Resonance Imaging (MRI): This technique produces high-resolution computerized images of internal tissues using a powerful magnet. In medicine, MRI is often used when pain is present alongside minimal X-ray findings, or when there are indications of damage to other joint tissues, such as a ligament or the knee’s cushioning connective tissue (known as the meniscus).
Other Tests
The doctor may order blood tests to rule out other causes. Joint aspiration may also be recommended, a procedure in which joint fluid is withdrawn using a needle and examined under a microscope. Samples of joint fluid may reveal bacteria, pointing to an infectious cause, or uric acid crystals, suggestive of gout.
Osteoarthritis is so common, especially among older adults, that there is a risk of attributing symptoms to it that are actually caused by other conditions. The doctor will attempt to identify the true cause of symptoms through a process of exclusion, also identifying factors that may be worsening the symptoms.
Treatment and Remedies
The most effective treatment programs are based on a combination of approaches tailored to the individual case, lifestyle, and overall health status. Most programs include methods for managing pain and improving function, but the four main goals of osteoarthritis treatment are:
- controlling pain,
- improving joint function,
- maintaining a healthy body weight,
- achieving an overall healthy lifestyle.
This is accomplished through:
- physical activity,
- weight management,
- non-pharmacological pain reduction techniques and complementary therapies,
- pain-relieving medications,
- surgery.
Physical Activity
Exercise has been shown to be one of the most effective remedies for osteoarthritis and represents a cornerstone of treatment.
Exercise can:
- improve mood and overall outcomes,
- reduce pain,
- increase flexibility,
- strengthen the heart and improve circulation,
- help manage body weight,
- promote overall physical fitness.
Physical activity can also be low-cost and, when performed correctly, carries few negative side effects. The type and amount of exercise recommended will depend on which joints are affected, joint stability, and any previous surgeries.
Walking, swimming, and water-based aerobic exercises are examples of physical activities suitable for people with osteoarthritis. A doctor or physical therapist can recommend specific exercises tailored to each individual case. It is also important to allow adequate time for rest and joint relief.
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Strengthening exercises: activities that strengthen the muscles supporting joints affected by arthritis. These can be performed using weights or resistance bands, inexpensive devices that add resistance to movements.
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Aerobic activities: exercises such as brisk walking or other low-impact activities that stimulate the heart and help keep the lungs and circulatory system in good condition.
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Range-of-motion exercises: help keep joints flexible and mobile.
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Balance and agility exercises: help preserve the skills needed for everyday activities.
Weight Management
If you are overweight or obese, working toward weight loss can be highly beneficial.
Reducing excess weight can:
- reduce stress on weight-bearing joints,
- limit further joint damage,
- increase mobility,
- reduce the risk of associated health problems.
A registered dietitian can help develop healthy eating habits. A healthy diet combined with regular exercise supports effective and sustainable weight loss.
Other Remedies
People with osteoarthritis can turn to various non-pharmacological methods to help relieve pain. These include:
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Heat and cold therapy: Both heat and cold (or a combination of the two) can be helpful for joint pain. Heat can be applied in various ways (warm towels, heating pads, warm baths or showers) and works by increasing blood flow, which helps reduce pain and stiffness. Cold packs (ice or frozen vegetables wrapped in a towel), on the other hand, reduce inflammation and can relieve pain or numb sensitivity in a swollen area. Ask your doctor or physical therapist which option, heat or cold, is best suited to your specific situation.
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TENS (Transcutaneous Electrical Nerve Stimulation): This technique uses a small electronic device to send mild electrical impulses to nerve endings beneath the skin in the affected area. TENS can help reduce some arthritic pain. It appears to work by blocking pain signals from reaching the brain and altering pain perception.
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Massage therapy: To relieve pain, a massage therapist manipulates or applies gentle pressure to sore muscles. This can increase blood flow and bring warmth to the affected area. However, joints affected by arthritis are sensitive, so it is important that the therapist has specific experience working with arthritic patients.
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Acupuncture: When conventional medicine fails to provide acceptable pain relief, patients are often more willing to try complementary and alternative therapies for osteoarthritis. Some patients report improvement with acupuncture, a practice in which thin needles are inserted by a trained practitioner (in many countries, a licensed physician with specialized training) into specific points on the skin. Part of the scientific community believes that the needles stimulate the release of natural pain-relieving chemicals produced by the nervous system, though solid evidence of effectiveness is still lacking.
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Dietary supplements: In some people with osteoarthritis, dietary supplements such as glucosamine and chondroitin sulfate, as well as certain vitamins, have been associated with symptomatic improvement. Additional research has been conducted to further investigate these claims. It remains unclear whether these supplements can actually alter the underlying course of the disease.
Medications
Doctors prescribe medications to eliminate or reduce pain and improve joint function. When selecting medications for a given patient with osteoarthritis, the doctor takes into account several factors, including:
- the intensity of pain,
- possible side effects of the medication,
- the patient’s medical history (other concurrent or potential health issues),
- any other treatments already in progress.
Because there can be interactions between medications, and because certain health conditions increase the risk of side effects, it is important to report all current treatments and full medical history before starting any new medication. Once therapy begins, regular follow-up visits with your doctor are essential. Working together with your physician, you can find the most effective treatment for reducing pain while minimizing the risk of side effects.
Osteoarthritis treatment typically involves the following types of medications:
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Over-the-counter analgesics: Oral pain relievers, such as acetaminophen (paracetamol), are often the first approach used to reduce pain in people with osteoarthritis.
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NSAIDs (Non-Steroidal Anti-Inflammatory Drugs): Commonly used in osteoarthritis treatment, NSAIDs are a broad group of medications with both pain-relieving and anti-inflammatory effects. Examples include aspirin, ketoprofen, nimesulide, and ibuprofen. Some NSAIDs are available over the counter, while more than a dozen of these compounds, including a subclass known as COX-2 inhibitors (celecoxib, etoricoxib, and others), require a prescription.
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Narcotics or centrally-acting pain medications: In cases where over-the-counter analgesics are ineffective and NSAIDs are contraindicated, doctors may prescribe stronger, targeted pain medications. These medications carry certain risks, including the potential for dependence.
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Corticosteroids: These are hormones with powerful anti-inflammatory effects (cortisone), either naturally produced by the body or manufactured for pharmaceutical use. They can be injected directly into affected joints as a temporary pain-relief measure (joint injections). This is generally considered a short-term solution and is typically not recommended more than two to four times per year, particularly since physical therapy often produces better long-term results. Oral corticosteroids are generally not used to treat osteoarthritis, though they may occasionally be used for acute inflammatory flare-ups.
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Hyaluronic acid substitutes: Sometimes called viscosupplements, these products are designed to replace a natural joint component involved in lubricating and nourishing cartilage. Depending on the specific product prescribed, administration typically requires a series of three to four injections directly into the joint (joint injection). These products are currently approved only for knee osteoarthritis.
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Other medications: Several other medications may be prescribed for osteoarthritis, including topical pain relievers in the form of creams, ointments, and sprays applied directly to painful areas.
Surgery
Surgery can help relieve pain and disability associated with osteoarthritis in many patients. Surgical procedures can address several different problems:
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Removal of loose bone or cartilage fragments within the joint if they are causing catching or locking symptoms (arthroscopic debridement or decompression).
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Realignment of bones (osteotomy).
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Joint resurfacing (essentially reconstructing a smooth joint surface).
Surgeons may also replace severely damaged joints with artificial implants (a common example being hip replacement surgery). These implants can be made from metal alloys, high-density plastics, and ceramic materials. Some implants are cemented directly to bone surfaces using special adhesives, while others have porous surfaces that allow bone to grow into the implant over time (a process called biological fixation), holding it securely in place. Joint replacement implants can last 10 to 15 years or even longer. The surgeon selects the specific implant model and components based on the patient’s weight, age, sex, activity level, and other health factors.
Advances in this field now allow, in some cases, for only the damaged portion of the knee joint to be replaced, leaving healthy areas of the joint intact, as well as performing hip replacement surgery through much smaller skin incisions than in the past.
The decision to pursue surgery depends on several factors, including age, occupation, degree of disability, pain intensity, and how much the condition interferes with daily life and lifestyle. Generally, after surgery and rehabilitation, patients experience less pain and swelling and are able to move more freely.
Frequently Asked Questions
What is osteoarthritis?
Osteoarthritis is the most common cause of joint pain. It results from the gradual thinning of cartilage, which becomes less able to allow bones to glide smoothly during movement. The joints most commonly affected include the knees, hips, lower back, and neck.
What are the symptoms of osteoarthritis?
The most common symptoms are pain and stiffness, particularly after periods of inactivity or upon waking in the morning.
How is osteoarthritis treated?
The primary goal of treatment is to slow the progression of cartilage breakdown, since true reversal is only rarely achievable. Weight loss and moderate, regular exercise generally form the foundation of treatment. The use of glucosamine and chondroitin sulfate supplements is not currently supported by strong scientific evidence.
During acute flare-ups, your doctor may recommend:
- anti-inflammatory and pain-relieving medications,
- joint injections.
Surgery is necessary in only a relatively small proportion of patients.
What should I eat if I have osteoarthritis?
There is no specific “osteoarthritis diet”, but the condition does benefit from a healthy, varied diet similar to what is recommended for the general population. A daily intake of unrefined plant-based foods, including fruits, vegetables, whole grains, and legumes, helps reduce the intake of pro-inflammatory foods and can also support healthy weight loss in overweight individuals. It is also recommended to drink plenty of water, as proper hydration helps support the health of synovial fluid.
