Pain in just 1 joint
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.
Inflammation of the joint lining
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.
Gout or pseudogout
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.
Damage to the cartilage at the back of the kneecap
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.
Bleeding into the joint space
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:
- swelling of the knee
- stiffness and bruising, which occur soon after the injury
Go to A&E immediately for treatment if you have a very swollen knee following an injury.
Less common causes
Sudden pain in a joint is less commonly caused by:
- a fracture – read about a broken arm or wrist, broken leg, broken ankle or hip fracture
- reactive arthritis – which usually develops after an infection and tends to affect young adults
- psoriatic arthritis – a type of arthritis that affects up to 1 in 5 people with psoriasis
- rheumatoid arthritis – which can start in just 1 joint, with the pain coming and going
- Osgood-Schlatter's disease – swelling and tenderness over the bony bump just below the kneecap
Rarely, the cause may be:
- septic arthritis – a serious health condition that causes a painful, hot, swollen joint that you will not be able to move (sometimes with a high temperature); see your GP urgently or go to A&E
- haemophilia – an inherited illness that affects the blood's ability to clot
- a tropical infection
- crumbling of the bone (avascular necrosis) – caused by a lack of blood supply
- repeated dislocation of the joint
Pain in many joints
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.
A viral infection that causes arthritis
Examples of viral infections that can cause pain in the joints and symptoms of a fever include:
- viral hepatitis – liver inflammation caused by a virus
- rubella – a viral infection that used to be common in children
A disease of the connective tissue
Widespread joint pain is sometimes a sign of a disease that affects almost all the organs of the body, such as:
- lupus – where the immune system mistakenly attacks healthy cells, tissue and organs
- scleroderma – where the immune system attacks connective tissue underneath the skin, causing hard, thickened areas of skin
Less common causes
Widespread joint pain can less commonly be caused by:
- a rarer type of arthritis – such as ankylosing spondylitis, juvenile arthritis or reactive arthritis
- Behçet's syndrome – a rare and poorly understood condition that causes inflammation of the blood vessels
- Henoch-Schönlein purpura – a rare condition, usually seen in children, that causes blood vessels to become inflamed
- some treatments – including steroid therapy, isoniazid and hydralazine
- hypertrophic pulmonary osteoarthropathy – a rare disorder that causes clubbing of the fingers, seen in people with lung cancer
- sarcoidosis – a rare condition that causes small patches of tissue to develop in the organs