8th October, 20206 min read

What is osteoarthritis — and what are the causes?

Medical reviewer:
Healthily's medical team
Healthily's medical team
Georgina Newman
Georgina Newman
Last reviewed: 09/10/2020
Medically reviewed

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Osteoarthritis is a type of arthritis that occurs when the soft tissue that protects the ends of the bones (cartilage) slowly wears away. If this happens, the bones may rub together, causing pain and making it harder for your joints to move.

Osteoarthritis can affect any joint in the body, but it’s most likely to affect your hands, knees and hips. It may also affect your spine or feet.

It's the most common form of arthritis, and your risk of developing it increases with age — early signs of the disease typically occur in people aged 50 or older.

But osteoarthritis is different from other types of arthritis in that it only affects your joints and not your organs.

Symptoms of osteoarthritis include:

  • feeling stiff after resting, such as when you wake up
  • not being able to move your joints easily
  • having joints that click and crack, for example when you bend your knees

What causes osteoarthritis?

Osteoarthritis is caused by wear and tear of the tissue between the joints. Age is a key factor, as the tissue and your joints slowly wear away as you get older.

However you’re also at risk from wear and tear if any of the following risk factors apply.

Your joints are used a lot, such as in a job

Though osteoarthritis is more common in older people, it can affect younger people, especially if they do a lot of high-impact sports like running, football or basketball.

These types of activities place extra stress and pressure on the joints, especially if you do them regularly for many years. Over time, this can contribute to the wearing down of cartilage.

Studies suggest that having a high body mass (BMI) as an athlete may increase your risk further, as even more pressure is placed on your joints due to the extra weight.

Studies also show that certain jobs may increase your risk of developing osteoarthritis. For example, hip osteoarthritis tends to be more prevalent in manual workers, including farmers, construction and agricultural workers, cleaners, miners and firefighters.

Heavy lifting and manual work has been shown to contribute to getting osteoarthritis in the knees, spine and neck. Dentists and construction workers are at increased risk of developing osteoarthritis in the hands as a result of using tools that vibrate.

Woman holding her wrist while sitting on a sofa

You’ve injured your joints

Osteoarthritis is also more common in athletes or people who play high-impact sports repeatedly as it’s more likely you will injure your joints.

If you injure a joint, this can cause the bones to knock against each other and bruise. Even if you recover from such an injury — or have surgery to repair any damage — there’s still a greater risk of osteoarthritis developing in the affected joint later in life.

Likewise, if you tear a ligament, this can damage the soft tissue (cartilage) between your bones. As this tissue lacks blood vessels, it can’t replace any damaged tissue cells easily. This makes it more likely that wear and tear will take place, especially if recovery is slow.

A sports injury can occur anywhere on your body and can affect your joints. Even a sprain can cause pain or swelling around a joint.

Runners may get knee strain or twist their knee. If this happens even once, your chance of developing osteoarthritis in your knees may increase.

Woman running on the road with knee taped up for support

You’re overweight

Being overweight (obese) increases your risk of developing osteoarthritis. The more weight you carry, the more stress and pressure there is on your joints. Over time, this can lead to damage.

Fat stored in the body also releases certain proteins that cause inflammation. The more excess fat you have, the more severe the inflammation, which affects all parts of your body, including your joints.

Losing weight can reduce your risk of developing osteoarthritis. Studies suggest that even losing a small amount of weight can reduce your risk of knee osteoarthritis or reduce pain if you do develop knee osteoarthritis.

Your genes and race

Osteoarthritis may occur as a result of differences in your genes. It’s thought that if you have certain genes your body may not be as good at repairing damage caused to your joints or the soft tissue (cartilage). This may increase the risk of wear and tear occurring.

However, it’s not yet clear how great a role your genes play in developing osteoarthritis. Your risk of developing osteoarthritis is likely to be greater if other risk factors are involved, such as being obese.

Your gender

Women have a higher risk of developing most types of osteoarthritis than men, especially after the age of 50.

It’s thought that because women usually have wider hips than men, this may place more pressure on the inside of the knee, potentially causing knee osteoarthritis.

Childbirth may also play a role. Studies suggest that women who have more children may be more likely to develop osteoarthritis in the knee or hip as a result of increased weight and pressure on the joints during pregnancy.

Having weaker muscles is also a potential risk factor for osteoarthritis.

Women have lower levels of the hormone testosterone than men, and it’s this hormone that builds muscle. If, for example, the muscles around the knees don’t provide enough support to the knee joints, this may increase your chance of getting knee osteoarthritis.

Doctor or physiotherapist treating a male patient

Managing osteoarthritis

If you think you may be developing osteoarthritis, there are ways to manage it and to reduce the risk of your symptoms getting worse.

This may include:

  • doing exercises to build muscle strength
  • doing low-impact exercise like swimming — to help keep you fit while putting less pressure on the joints
  • losing weight if you’re overweight

See a doctor if you’re getting pain in your joints. They will be able to diagnose any problems and help you find appropriate treatment.

Key points

  • osteoarthritis affects the joints, the structures between 2 bones
  • it’s the most common form of arthritis
  • symptoms include stiff and painful joints, and clicking or cracking joints
  • it’s caused by the wear and tear of soft tissue (cartilage) near the joints
  • you’re at increased risk of developing osteoarthritis if you’re above the age of 50, are overweight, have injured your joints or your joints have been subject to repeated wear and tear

[AD] Got questions about osteoarthritis? Talk to a doctor online to help you get answers. Use code HEALTHILY5 to get £5 off your first appointment.

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