​Osteoarthritis involves changes to the surface of your joints. The cartilage covering the ends of the bones roughens and becomes thinner. This can happen within the knee joint and the undersurface of the knee cap. The bone next to the cartilage can also be affected and bony growths can develop around the edges, these growths are called osteophytes. Baker's cysts are another common finding in osteoarthritis; this is a swelling at the back of the knee.

What are the symptoms of knee osteoarthritis?

Symptoms of knee osteoarthritis include:

  • Pain – especially when weight bearing, such as walking. This can be occur in different places in the knee dependent on the area affected.
  • Stiffness – often this can be worse in the morning or after prolonged periods of rest.
  • Swelling
  • Grinding when the joint moves
  • Weakness 

The level of pain can vary from person to person, with some people reporting a mild niggle that comes and goes and others reporting a severe ache that can keep people awake at night.

What causes knee osteoarthritis?

There often isn't one individual cause for knee osteoarthritis. Osteoarthritis is the most common form of arthritis in the UK and can develop from middle age onwards.

Factors that may play a role in the development of knee osteoarthritis include:

  • Age - osteoarthritis becomes more common with increasing age
  • Obesity – increased load and demand for knee structures to support
  • Previous injury and surgery – for example previous fractures, meniscal or ligament injuries
  • Vigorous repetitive activities - normal activities and exercise however do not cause arthritis and is in fact preventative
  • Genetics

How is it diagnosed?

Diagnosis is usually made from the patient's history and a simple examination without the need for further investigations. Sometimes an x-ray may be arranged if a clinician is uncertain about the diagnosis or wishes to see the extent of the osteoarthritis.

How can I manage knee osteoarthritis?

There is self-management advice provided below to help minimise symptoms and facilitate the healing process:

Pain relief

Painkillers such as paracetamol and ibuprofen or anti-inflammatory gels may be helpful to control the pain and allow you to continue exercising. Discuss this with your GP or pharmacist.

Weight loss

If you are overweight, reducing your weight can also improve symptoms through reducing the stress on your joints.


Regular exercise is important, specific exercises to strengthen the joint can further help protect the knee from flare ups of pain.
Increasing day to day activity levels has also been shown to improve some symptoms of osteoarthritis. Aim to do 150 minutes of moderate intensity aerobic exercise (such as cycling or fast walking) every week.

Further management options

If there is no improvement in your symptoms with the self-management information above within four to six weeks, seek further advice from your physiotherapist or GP.