Knee pain is one of the most common bone and joint problems, and its knee pain causes and treatment depend on your age, your activity and what is happening inside the joint. It can affect teenagers who play sport, adults who sit or stand for long hours, and older people whose joints have worn with time. This guide explains the common causes, the symptoms to watch for, what you can do at home, and when to see a doctor.
Quick answer
Most knee pain comes from wear and tear of the joint, overuse or a minor injury, and many people improve with gentle exercise, a healthy weight and physiotherapy. See a doctor if the pain lasts more than a few weeks, keeps coming back, or comes with swelling, a knee that gives way, or difficulty walking. Surgery is needed only in a small number of cases, after simpler treatment has been tried.
What is knee pain?
The knee is the joint where the thigh bone, the shin bone and the kneecap meet. Smooth cartilage covers the bone ends, and a pair of C-shaped pads called the menisci act as cushions. Ligaments keep the joint stable, and tendons and muscles move it. Pain can start in any of these parts. It can be a dull ache after a long day, a sharp pain with a particular movement, or a constant pain that wakes you at night.
Knee pain causes
Wear and tear (osteoarthritis). Over the years, the cartilage can thin and the joint becomes stiff and painful. This is a common cause of knee pain after the age of 40 to 50. It is more likely with extra body weight, an old injury, or a family history.
Injuries. A fall, a twist during sport, or a road accident can cause a ligament tear, a meniscus tear, a dislocated kneecap or a fracture. These injuries usually cause pain and swelling soon after, and sometimes a feeling that the knee is unstable.
Overuse. Repeated stress, such as running, climbing stairs many times a day, or kneeling for long periods, can irritate the tendons, the kneecap area or the fluid sacs around the joint. Pain around or behind the kneecap is common in young, active people.
Inflammation and infection. Conditions such as rheumatoid arthritis and gout can make the knee hot, swollen and painful. A joint infection is less common but is an emergency.
Pain from elsewhere. Sometimes pain felt in the knee actually comes from the hip or the lower back, so a doctor may examine those areas too.
Symptoms of Knee Pain
Knee pain can show up in different ways. Common signs include:
- pain when walking, climbing stairs, squatting or getting up from a chair
- stiffness, especially after resting or in the morning
- swelling around the knee
- clicking, grinding or catching during movement
- a feeling that the knee may give way
- difficulty fully bending or straightening the knee
- the knee locking in one position
When to see a doctor
See a doctor soon if:
- the pain lasts more than a few weeks, or is not getting better with home care
- the swelling keeps coming back
- the knee gives way or feels unstable
- you find it hard to climb stairs or walk your usual distance
- the pain wakes you at night
Go to a hospital urgently if:
- you had a serious fall or injury and the knee looks deformed, or you cannot put weight on the leg
- the knee is red, hot and swollen, especially with a fever
- you have severe pain with swelling or tightness in the calf
- you have numbness or weakness in the leg
Treatment options
The right treatment depends on the cause, your age, how severe the problem is, and how it affects your daily life. A doctor will usually ask about your symptoms, examine the knee and, if needed, advise an X-ray or other tests.
Home care. Avoid activities that clearly make the pain worse, but do not stop moving completely, because long rest can make the joint stiffer. Many people find that a cold pack after an injury, or warmth for stiff joints, gives comfort. Comfortable, supportive footwear can help.
Exercise and physiotherapy. Strengthening the muscles around the knee, especially the thigh muscles, helps to support and protect the joint. Low-impact activities such as walking on flat ground, cycling and swimming are often well tolerated. A physiotherapist can teach exercises that suit your knee and your problem.
Weight management. Extra body weight puts more load on the knees. Even modest weight loss can reduce pain for many people with knee arthritis.
Medicines and injections. A doctor may advise pain relief or other medicines, and in some cases injections. Please do not take medicines regularly or for a long time without advice, especially if you have stomach, kidney or heart problems, or take other medicines.
Supports. In some cases, a knee support or a walking aid may help. Ask your doctor or physiotherapist whether it suits you.
Surgery. Surgery is considered only for some problems, such as certain ligament or meniscus injuries, or severe arthritis when pain and stiffness greatly limit daily life and other treatment has not helped. The decision is made after an examination and tests, and after discussing the benefits and risks with you.
Prevention and self-care
You cannot prevent every cause of knee pain, but these habits help to protect your knees:
- stay active every day, with a mix of walking and gentle strengthening exercises
- keep a healthy body weight
- warm up before sport and increase activity slowly
- wear well-fitting, supportive footwear
- take breaks if you kneel, squat or climb stairs a lot
- if sitting on the floor or using a squat toilet is painful, ask your doctor or physiotherapist about alternatives such as a chair or a raised seat
- treat injuries early instead of playing through the pain
Frequently asked questions
Is walking good for knee pain? Gentle, regular walking usually helps to keep the joint moving and the muscles strong. Start with short walks on flat ground. If the pain becomes sharp or keeps getting worse, stop and speak to a doctor.
Do I need an MRI for knee pain? Not always. Many cases can be understood from your history, an examination and an X-ray. An MRI is used when a ligament or meniscus injury is suspected, or when the cause is not clear. Your doctor will decide if it is needed.
Does knee pain mean I will need a knee replacement? No. Most people with knee pain never need a knee replacement. Replacement is considered only for severe damage, after other treatment has been tried.
Can knee pain go away on its own? A minor strain often settles within days to weeks. Pain from arthritis tends to come and go, and it usually improves with exercise and weight control. If the pain lasts more than a few weeks or keeps returning, see a doctor.
This article is for general education and does not replace advice from your own doctor. If you have severe pain, an injury, or symptoms that worry you, see a doctor in person.