Overview
Knee pain is one of the most common complaints, affecting people of all ages. It can result from injuries, overuse, or underlying conditions such as arthritis. The knee is the largest and most complex joint in the body, making it vulnerable to a wide range of problems.
Common Causes
- Osteoarthritis — wear and tear of the knee joint cartilage
- Ligament injuries — such as ACL or MCL tears
- Meniscus tears — damage to the cartilage pads in the knee
- Bursitis — inflammation of the fluid-filled sacs
- Patellar tendonitis — inflammation of the tendon below the kneecap
- IT band syndrome — from overuse in runners
- Patellofemoral syndrome — pain around the kneecap
- Gout — uric acid crystals in the knee joint
Symptoms
- Pain — ranging from a dull ache to sharp, stabbing pain
- Swelling and stiffness
- Weakness or instability
- Popping or crunching sounds
- Difficulty fully straightening or bending the knee
Treatment Options
- RICE method — Rest, Ice, Compression, Elevation
- Pain medications — paracetamol, NSAIDs
- Physiotherapy — strengthening and stretching exercises
- Knee supports and braces
- Weight management
- Corticosteroid or hyaluronic acid injections
- Surgery for severe damage (knee replacement, arthroscopy)
Common causes by pattern
Knee pain has many causes, and where and when it hurts gives useful clues. This list is a guide, not a diagnosis.
- Aching when walking or on stairs, stiffness after sitting, and sometimes creaking, especially over 45: often knee osteoarthritis.
- Pain around or behind the kneecap, worse on stairs, squatting or after sitting with bent knees: often patellofemoral pain, common in active younger people.
- Pain on the inner or outer side after a twist, sometimes with swelling, catching or locking: may be a meniscus (cartilage) problem.
- Pain just below the kneecap in people who run or jump: often a tendon problem.
- A soft swelling on the front of the knee after a lot of kneeling: may be bursitis.
- Swelling of several joints, long morning stiffness or feeling unwell: may be inflammatory arthritis, which needs a GP review.
- A sudden, very painful, hot, red swollen big toe or knee: can be gout or pseudogout.
What helps most knee pain
For most everyday knee pain, keeping moving is more helpful than prolonged rest. Rest from the activity that provokes it for a short time if you need to, but stay active in other ways.
Strengthening the muscles at the front and back of the thigh and around the hip is one of the most reliable ways to reduce knee pain and improve function, including in osteoarthritis. Start with a few simple exercises such as sit-to-stands from a chair, straight leg raises and step-ups, and build up gradually. Some discomfort during exercise is normal, but pain should settle back to your usual level within a day.
Other things that help include losing weight if you are carrying extra, comfortable shock-absorbing shoes, a walking pole or stick in the opposite hand on bad days, and anti-inflammatory gel on the knee after checking with a pharmacist.
Resting, icing and supports
After a minor strain, short-term measures such as relative rest, an ice pack wrapped in a towel and elevation can ease swelling. For stiff, arthritic knees many people prefer warmth. Knee sleeves and supports can make some people feel more confident, but they do not replace strengthening. Avoid wearing a brace all day unless a clinician has recommended it.
Seeing a professional
In many areas you can refer yourself to NHS physiotherapy or a first contact practitioner at your GP surgery. They can examine your knee, explain what is going on and set up an exercise plan. X-rays are not always needed to diagnose knee osteoarthritis in people over 45 with typical symptoms, and scans are usually reserved for when the result would change what happens next.
When to seek urgent help
Some knee problems need prompt medical attention.
- Go to A&E or call 999 if the knee is hot, red and very swollen and you have a fever or feel unwell, because a joint infection needs same-day treatment.
- Go to A&E or an urgent treatment centre if you cannot put weight on the leg after an injury, the knee looks deformed, or you heard a pop followed by rapid swelling.
- Get urgent medical help if your calf is swollen, red and painful, as this can be a blood clot.
- See your GP soon if the knee keeps locking or giving way, or if several joints are swollen.
About this page
Written by Louis Maxwell, First Contact Practitioner (HCPC PH128483), and pending clinical review. This is general information, not a diagnosis. Always follow the advice of your own GP, physiotherapist or rheumatology team. For emergencies call 999; for urgent advice use NHS 111.