Osteoarthritis, explained

Knee pain, aching joints, sore back, hip stiffness – these are all common complaints with many possible causes, including osteoarthritis. Although not curable, osteoarthritis can be managed and its progression slowed. Read on to find out what osteoarthritis is, how it’s diagnosed and treated, and what you can do to manage symptoms.


What is osteoarthritis?

Arthritis is often thought of as a single disease. In fact, it is an umbrella term for more than 100 medical conditions that affect the joints and surrounding connective tissues (muscles, tendons and ligaments). 

Osteoarthritis is the most common form of arthritis.

Find out more about other kinds of arthritis.

Knee joint showing the typical changes of osteoarthritis

Osteoarthritis affects all parts of a whole joint, including bone, cartilage, ligaments and muscles. In osteoarthritis, you may get:

  • inflammation of the tissue around a joint
  • damage to joint cartilage – this is the protective tissue on the ends of your bones which allows your joints to move smoothly
  • bony growths around the edge of a joint
  • changes to ligaments and tendons that can cause pain.

Osteoarthritis can affect any joint, but most commonly occurs in knees, hips, big toes and fingers.

People of all ages can develop osteoarthritis but it is most common in people over 40 years of age or those who have had joint injuries.

Osteoarthritis that develops slowly and progressively in a previously healthy joint is known as ‘primary’ osteoarthritis.

Osteoarthritis in joints that have been injured or damaged is called ‘secondary’ osteoarthritis.

What causes osteoarthritis?

Osteoarthritis is caused by inflammation, breakdown, and eventually, loss of cartilage in the joints.

In healthy joints, cartilage is smooth and slippery and acts as padding to prevent bones from rubbing against each other. The space between the smooth cartilage of the bones in a joint is lubricated by a thick fluid called synovial fluid.

In joints with osteoarthritis, the cartilage becomes damaged which leaves bones unprotected and vulnerable to further damage.

These factors can increase your risk of developing osteoarthritis:

  • Age – Osteoarthritis becomes more common with increasing age.
  • Previous joint injury or damage – This can include a previous joint infection, break (fracture) in the bone around a joint, or a previous ligament injury that caused a joint instability.
  • Overuse of the joint – For example, osteoarthritis of the knee may be more common in people who have jobs involving repetitive kneeling, climbing or squatting
  • Overweight and obesity – Knee and hip osteoarthritis are more likely to develop, or be more severe, in overweight and obese people. This is because there is an increased load on the joints and potential for more joint damage.
  • Gender – Women are more likely than men to develop osteoarthritis.
  • Family history – Some types of arthritis run in families, so you may be more likely to develop arthritis if your parents or siblings have the disorder. 

How is osteoarthritis diagnosed? 

A diagnosis of osteoarthritis is based on history, symptoms and a physical examination of affected joint(s). For example, the doctor might examine your knees by moving them forward and back to note your range of motion, and to find out which movements cause pain.

Tests such as X-rays or blood tests are usually not needed, because if you have osteoarthritis, results from these types of tests don’t usually change how you need to be treated and managed. An X-ray may be useful if your doctor is uncertain about the diagnosis and wants to exclude other problems. A blood test may be helpful if your doctor wants to rule out another type of arthritis.

Not everyone with osteoarthritis will have symptoms, and sometimes people may experience severe symptoms but X-rays show only minor changes to joints.

What are the symptoms of osteoarthritis?

Symptoms vary from person to person, and also depend on which joints are affected. Symptoms and signs can include:

  • Joint pain that is worse during activity and is better with rest. Pain at night or during rest can occur in advanced disease.
  • Joint stiffness that may be worse in the morning or after rest, which gets better soon after movement.
  • Tenderness around the joint.
  • Crepitus (a crinkly, crackling or grating feeling in the joint)
  • Swelling, caused by a build-up of fluid in the joint. If the knee is red or a fever develops, the problem is likely to be something other than osteoarthritis.
  • Enlarged joints caused by bony growths called osteophytes that form as the cartilage breaks down.

Some people with osteoarthritis may develop other problems if their symptoms get worse. Chronic pain and losing the ability to carry out daily activities can cause depression and/or anxiety in some people, or pain may affect the quality of their sleep.

If you need help with managing other symptoms that may be related to osteoarthritis, speak to your doctor first to find out what kind of health professional is the right person to see. You may need a referral for some types of treatment.

Find out more about managing osteoarthritis.

Osteoarthritis – what can I do?

There are actions you can take to help prevent and reduce the impact of osteoarthritis on your daily life.

Learning how to manage your osteoarthritis effectively involves building skills such as goal setting, decision making, problem solving and self-monitoring.

Taking an active role in managing osteoarthritis has been shown to improve outcomes

Research shows that people with osteoarthritis who participate in self-management education programs improve their skills and confidence to manage their condition. This can also improve both mental health (including anxiety and depression) and physical health.

Learn about new treatments, what works best, and other up-to-date information on the myjointpain website.

Download free fact sheets on a range of topics about arthritis from the Arthritis Australia website.

Find out more about managing osteoarthritis.

Medicines used to treat osteoarthritis

If you are experiencing pain related to your osteoarthritis, there are several medicine options for you to choose from. Starting with a cream or gel before moving to oral medicines may be a good option, or a combination of the two may be more effective at relieving aches and pains.

Topical treatments (creams or gels)

Topical medicines that reduce inflammation can be rubbed on to the skin over affected joints for pain relief. Examples include products that contain the active ingredient ibuprofen or diclofenac.

These treatments can be as effective as oral pain relievers for some people, especially if you have osteoarthritis in more accessible joints such as the knee or hand. Topical treatments are also well tolerated.

Oral medicines


Paracetamol is commonly used to treat osteoarthritis. However, a recent study found that, on its own, it provided minimal pain relief for osteoarthritis. Paracetamol has fewer side effects than non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, naproxen or diclofenac, but large doses of paracetamol can damage the liver.

Find out more about safe use of paracetamol.


If paracetamol or topical treatments do not provide suitable pain relief from osteoarthritis, some people may find over-the-counter oral NSAIDs helpful. Not everyone can use these medicines on a regular basis everyone. So it is recommended that you speak with your doctor, nurse or pharmacist to ensure oral NSAIDs are an option for your condition.

Opioid medicines

Opioids are a group of medicines that are commonly used to treat severe acute pain or cancer pain. However they are often not very effective in chronic pain that is not caused by cancer. Opioid medicines may contain active ingredients such as morphine, codeine, oxycodone, tramadol, or methadone. International osteoarthritis guidelines only recommend strong opioids in exceptional cases. They are only available with a prescription from your doctor.

Learn more about opioid medicines and chronic pain.

Learn more about pain relief options.


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