Osteoarthritis – facts, symptoms, diagnosis & treatment

Osteoarthritis (OA)  is the world’s most common joint disease with over 500 million people affected worldwide. But what is osteoarthritis, what happens to an osteoarthritis-affected joint and what are the main symptoms of the disease?

Osteoarthritis can affect any joint in the body but is most common in the knees, hips and fingers. Due to population aging and a steady growth in obesity, the worldwide prevalence of the disease is increasing each year.

A highly prevalent joint disease

Osteoarthritis affects over 32,5 million people in the US and about 25% of all adults over the age of 40 have been diagnosed with osteoarthritis. However, it is difficult to know the true number of people affected as many don’t seek care or treatment until the very late stages of the disease. Failure to seek care when experiencing joint pain or stiffness may be due to the fact that these symptoms are often accepted as part of aging. Therefore, educating oneself about osteoarthritis is very important as increased knowledge of early symptoms plays a major role in the treatment of the disease.

Symptoms of osteoarthritis

Osteoarthritis symptoms often develop gradually and are mainly characterized by joint pain and stiffness, especially in connection with activities that put stress on the joint. Occasionally, and usually in later stages of the disease, pain during rest and pain at night may occur. Other symptoms include swelling, tenderness and in certain cases, redness. In osteoarthritis of the knee, knee mobility is often affected. The knee may feel stiff, especially in the mornings or after sitting still. It may also lock and snap or pop.

If you have hip osteoarthritis, you often experience groin pain that radiates all the way down to the knee. In osteoarthritis of the fingers, your fingers may swell up. It is also relatively common for bony lumps to appear on the finger joints. However, the vast majority of people with the disease can live an active and often pain-free lifestyle with the help of supervised, individualized exercises.

How osteoarthritis is diagnosed

Osteoarthritis is a clinical diagnosis, which means that it is diagnosed based on your answers to questions about your symptoms, medical history and joint function. You may also be required to perform different physical function tests. An X-ray isn’t needed, unless your healthcare professional is uncertain about the diagnosis. Symptoms and radiographic findings are generally inconsistent. If you experience joint pain or stiffness, you should contact your healthcare center and book an appointment with a physical therapist or a doctor.

How does osteoarthritis affect the joint?

Osteoarthritis affects the entire joint, i.e. the cartilage, bone, menisci, ligaments, synovium and tendons. However, it is often said that the disease is characterized by the deterioration of the cartilage. This is because most research has primarily focused on what happens to the cartilage when a joint is affected by osteoarthritis.  

Cartilage is a connective tissue, found in many different parts of the body. There are three types of cartilage, but articular cartilage is the most common type. The articular cartilage is the type of cartilage that covers the joint surfaces on the end of the bones in a joint. It is what makes them slippery so that they can easily slide against each other when we move.  The articular cartilage also helps to distribute the force that our joints are exposed to on a daily basis.


In the healthy joint there is a continuous turnover (breakdown and rebuilding) of the articular cartilage. When a joint is affected by osteoarthritis, the cartilage breaks down faster than it is rebuilt. This makes it difficult for the joint surfaces to slide smoothly against one another. This can cause stiffness and pain in the joint and the joint may make cracking noises. Exactly what it is that causes this degeneration of cartilage, we do not yet know.  Neither can we ascertain the order of osteoarthritis changes that occur in the joint. What we do know is that these changes cause symptoms and that they are related to several risk factors.

Risk factors for ostearthritis

Anyone can develop osteoarthritis. Although it isn’t possible to identify the exact reason for why a person develops the joint disease, we know that multiple risk factors for osteoarthritis, both modifiable and non-modifiable, exist. Known modifiable risk factors include:

  • Excess body weight
  • Physical workload
  • Muscle weakness
  • Joint injuries

Known non-modifiable risk factors include age, genetics and female sex.

Although age is a risk factor, osteoarthritis is not a consequence of aging. However, the older we get, the longer our joints are exposed to stress and other risk factors that may cause the joint disease.

Osteoarthritis prevalence is higher among postmenopausal women. Women are twice as likely as men to develop the joint disease. The genetic influence is between 40-65%, depending on which joint is affected.

Early development after joint injury

Osteoarthritis can also develop as a result of acute trauma to the joint at a young age. This is known as post-traumatic osteoarthritis. The most common joint injuries that increase the risk of developing the joint disease later in life are meniscus tears, especially in combination with ligament tears. All patients, no matter age, should be offered first-line treatment for osteoarthritis. First-line treatment is a combination of exercise and patient education.

How osteoarthritis is treated

Although osteoarthritis is a chronic disease, it can be nice to know that it can be treated. With the right information and supervised exercises, it is possible to treat and relieve symptoms. Being diagnosed with osteoarthritis doesn’t mean that you won’t be able to do the same activities as before. With the help of first-line treatment which includes patient information and individualized exercises, you stand a great chance of living an active lifestyle with less pain. All patients should be offered first-line treatment immediately after diagnosis to get the best possible results. You can receive individualized exercises from a physical therapist.

Other treatment methods such as painkillers and surgery may act as a complement to first-line treatment when it isn’t giving satisfactory results. Nevertheless, exercise is the main treatment method that should be offered to all patients, regardless of disease stage.

Preventing osteoarthritis

There are several lifestyle changes that can be made to reduce the risk of developing or worsening osteoarthritis. First you can see if you have any risk factors for osteoarthritis, as some can be modified or avoided. Modifiable or avoidable risk factors include sports injuries, body weight, physical inactivity, weak muscles, work posture and physical workload. The more risk factors you have, the greater the risk is of developing the disease. 

You may, for example, be able to avoid excessive physical workload or vary work posture. Being physically active throughout life can also help prevent osteoarthritis. Our joints need to move and physical inactivity is neither good for our joints or our overall health. If you are overweight, you could try changing your diet and exercise habits. However, it’s  mostly about making sure that your muscles are strong enough to carry your body weight. Therefore, it’s more important to exercise to strengthen your muscles than to focus on losing weight.

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