Knee pain symptoms and causes

Medically reviewed by:

Dr Eddie Roche - Medical Officer

Updated: Aug 18, 2021

Next review: Aug 18, 2022

Knee pain is common and can be caused by many different things.

Your knees take the full weight of your body. Like your hips, they are the foundation upon which the weight of your body sits so they get lots of use when you’re moving around and are more vulnerable to damage, compared to other parts of your body.

Knee pain can commonly occur following an injury, such as ruptured ligament, a torn cartilage or bleeding in the joint. Or it could be caused by overuse or even an underlying condition, such as arthritis, gout or an infection.

If you’re struggling with knee pain, our doctors can help.

The symptoms of knee pain will depend on what’s causing it. However, common things to look out for include:

Swelling
Stiffness
Redness
Warmth (to touch)
Crunching or popping noises
Not being able to fully straighten your knee
Locking of the knee
Instability of the knee, which can be particularly noticed when walking down stairs
Knee pain when walking

Knee pain can affect people of all ages. However, as you get older, you’re more likely to experience it because of normal, day-to-day wear and tear.

If you take part in lots of sports, you’re also more prone to knee pain, particularly if you play ones that involve lots of turning and sudden stop-starting, such as football and tennis.

And if you’re overweight, you’re more likely to suffer with your knees, because of the extra weight they are carrying.

Associated conditions

Injury is the most common cause of knee pain. Whether it’s from a blow to the knee, twisting, bending or falling, you’ll usually have instant pain, swelling and tenderness. It could be a sprain, strain or tear, a break, fracture or dislocation.

If your knee pain is has come on more gradually, it could be because of an underlying condition, including:

Osteoarthritis is the most common form of arthritis. It causes damage to the articular cartilage, which protects your knees. It can also cause swelling of the tissues in and around your joints. Osteoarthritis usually comes with age or overuse.

If you think your knee pain is down to Osteoarthritis, speak to a doctor. They can recommend ways to reduce the strain on your knee.

Rheumatoid arthritis is an autoimmune condition that can affect almost every joint in your body, including your knees.

You may have pain, swelling and stiffness in your knee for no obvious reason over a long period of time. It may be worse after periods of rest and better with activity. Often, you will have flare ups, when the condition is more severe.

Learn more about arthritis

Gout usually starts with a very sudden and severe pain in one of your joints, often affecting the joint of the big toe, but it can also affect your knees. The joint may hot and tender to touch, and it may also be swollen, with red, shiny skin.

Learn more about Gout

If your knee is hot, swollen and painful, it could be an infection.

You may also have other symptoms of an infection, such as having a fever and generally feeling poorly. You should go to A&E if you think this is what you’re suffering from.

If the tendons around your knee become inflamed, it’s called tendonitis. It can be brought on by a jumping motion, common if you play sports such as basketball.

Your knee may also be swollen, tender and warm to the touch.

If you have pain in your knee that gets worse when you kneel or bend, it could be down to a swelling called a bursitis. This is caused by a repetitive movement in your knee, or kneeling for a long period of time. This can mean fluid builds up over the knee joint. It’s sometimes called ‘housemaid’s knee’.

As well as knee pain, it can also be swollen and may be warm to touch, red and tender.

Common in teenagers and young adults who play a lot of sport, Osgood-Schlatter’s disease causes tenderness and swelling in the bony bump that sits just below the knee.

It happens when this section of the lower leg is damaged during a growth spurt.

These are not all of the possible causes - see a GP for more advice.

If you believe you may have an underlying condition that’s causing your knee pain, it’s a good idea to see a doctor.

Also, see a doctor if you:

Can’t put any weight on your knee or it gives way when you do.
Have bad pain even when you’re not putting weight on it.
Notice a deformity in the knee.
Can’t extend it or bend it.
Have painful clicking sensation.
Have lot of swelling.
Have a fever, as well as swelling and redness on your knee.
Have had pain for more than a few weeks.

At Push Doctor, you can see a GP online from home, work or even on the go, on any device. They can look at your knee over video consultation, listen to your symptoms and suggest the right treatment to get you back up on your feet as quickly as possible.

You can see a GP about your knee pain at a time that suits you. Our doctors are available 7 days a week and can offer you the advice you may need. They can also refer you to a specialist for further investigation or treatment.

In order to reduce the risk of knee injury, or knee re-injury, it is important that you strengthen the muscles and connective tissues (tendons and ligaments) around the knee. Here are a few exercises to strengthen the lower limb.

Knee pain

Dr Eddie Roche - Medical Officer

What is knee pain?

Symptoms

Susceptibility

Associated conditions

Injuries

Osteoarthritis

Rheumatoid arthritis

Gout

Infection (septic arthritis)

Tendonitis

Bursitis

Osgood-Schlatter’s disease

When to see a doctor

Knee pain treatment online

Exercises to prevent knee pain

Dr Eddie Roche - Medical Officer

What is knee pain?

Symptoms

Susceptibility

Associated conditions

Injuries

Osteoarthritis

Rheumatoid arthritis

Gout

Infection (septic arthritis)

Tendonitis

Bursitis

Osgood-Schlatter’s disease

When to see a doctor

Knee pain treatment online

Exercises to prevent knee pain

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