Joint pain is a very common problem with many possible causes, but it's usually a result of injury or arthritis.
In older people, joint pain that gets steadily worse is usually a sign of osteoarthritis. It may affect just 1 joint or many.
See your GP if you have persistent symptoms of osteoarthritis.
The information and advice on this page should not be used to self-diagnose your condition, but may give you a better idea of what's causing your pain.
The knee joint is probably the most frequently damaged joint and is particularly vulnerable as it takes the full weight of your body.
But knee pain is not always a joint problem. Learn about the most common causes of knee pain and what you should do.
If you have injured the joint recently and it suddenly becomes painful again, the thin layer of tissue lining the joints and tendons may be inflamed, a condition called traumatic synovitis.
It usually does not cause any redness or heat.
You should be able to manage injury-related swelling at home with anti-inflammatory medicines, such as ibuprofen, an icepack and rest.
If the skin over the joint is hot and red, and the pain comes in repeated attacks, the cause is likely to be either gout or pseudogout.
Both of these are types of arthritis.
Gout usually affects the joint of the big toe first before affecting other joints.
It's important to correctly diagnose gout, as treatment will prevent future attacks of joint pain and disability.
Pseudogout is similar to gout, but usually affects the knee joint first.
See your GP if you think you have gout or pseudogout.
Knee pain that feels worse when you go up or down stairs could be a sign of a damaged kneecap, called chondromalacia patellae.
This should not cause any redness or heat around the knee.
The cause is not understood, but it can be linked to overuse of the knee.
You can treat this problem yourself with anti-inflammatory medicines, such as ibuprofen, an icepack and rest.
If you have recently had an injury to the knee joint, such as a torn ligament or knee fracture, it may cause bleeding into the joint spaces. This is known as haemarthrosis.
Signs of haemarthrosis are:
Go to A&E immediately for treatment if you have a very swollen knee following an injury.
Sudden pain in a joint is less commonly caused by:
Rarely, the cause may be:
Rheumatoid arthritis is a type of arthritis that causes pain and swelling in the joints, usually the hands, feet and wrists.
The pain may come and go in the early stages, with long periods between attacks.
It can make you feel generally unwell and tired.
Psoriatic arthritis affects up to 1 in 5 people with psoriasis.
This type of arthritis is unpredictable, but flare-ups can usually be controlled with treatment.
Like other types of arthritis, it means that 1 or more of your joints are inflamed and become swollen, stiff, painful and difficult to move.
Examples of viral infections that can cause pain in the joints and symptoms of a fever include:
Widespread joint pain is sometimes a sign of a disease that affects almost all the organs of the body, such as:
Widespread joint pain can less commonly be caused by: