Symptoms · · 8 min read

Knee pain: causes, home care and when to get checked

Knee pain is common and has many causes, from a sprain or tendon problem after an injury to osteoarthritis that builds up over years. Many cases can be treated at home with less load on the knee, ice and over-the-counter pain relief, followed by gradual movement and strengthening. See a clinician if the pain does not improve within a few weeks, and get urgent care if you cannot put weight on the leg, the knee changes shape or locks, or it is hot, red and you have a fever.

Illustration of a knee joint with a pain mark, an ice pack and a resistance band

In short

  • Knee pain has many causes. The NHS advises not to self-diagnose and to see a clinician if you are worried.
  • For many causes, home care starts with putting as little weight as possible on the knee, an ice pack and over-the-counter pain relief.
  • Osteoarthritis, the most common knee disease, is managed mainly with exercise and weight management, not with rest.
  • An X-ray is usually not necessary to diagnose osteoarthritis. It is used when other causes need to be ruled out.
  • See a clinician if the pain does not improve within a few weeks, and get urgent care for the warning signs below.

Common causes

The knee is made of bone, cartilage, ligaments and fluid, with muscles and tendons helping it move. A problem in any of them can cause pain and difficulty walking.

  • After an injury: sprains and strains, tendonitis, a torn ligament, tendon or meniscus, or a dislocated kneecap. The ACL is often injured by a sudden twisting motion.
  • Without an obvious injury: osteoarthritis, bursitis, bleeding in the joint, gout or septic arthritis, and in teenagers and young adults a condition called Osgood-Schlatter disease.
  • Osteoarthritis: the most common knee disease, in which the cartilage gradually wears away and causes pain and swelling.

Risk factors for osteoarthritis include older age, a past joint injury, repeated overuse, family history and being overweight. The WHO notes that obesity is especially linked with hip and knee osteoarthritis.

What to do at home

  1. Ease the load.Put as little weight as possible on the knee while it is sore.
  2. Ice it.Use an ice pack or a bag of frozen peas wrapped in a cloth for up to 20 minutes every 2 to 3 hours.
  3. Pain relief.The NHS lists acetaminophen (called paracetamol in the UK) or ibuprofen as gel or tablets. Check with a pharmacist or clinician if you have stomach, kidney or heart problems or take other medicines.
  4. Keep moving gently.Once the worst pain settles, return to everyday activity step by step rather than staying in bed or on the couch.

Painless clicking or cracking in the knee is normal. The NHS points to a painful click, locking or the knee giving way as reasons to be checked.

Exercise and weight

For osteoarthritis, the NHS recommends regular exercise and losing weight if you are overweight, plus suitable footwear. Its guidance for adults is about 150 minutes of moderate aerobic activity a week and strength exercises on two or more days. The WHO says exercise strengthens the muscles around an affected joint and improves mobility, and that a healthy weight reduces symptoms.

If the pain is more severe, a structured exercise plan with a physical therapist can help. Ask what level of activity is safe for your knee right now, and which exercises suit your cause of pain.

Osteoarthritis: what to know

Osteoarthritis is a degenerative joint condition in which the tissues in the joint break down over time. The main symptoms are pain, stiffness, swelling and trouble moving the joint. Stiffness in the morning or after resting usually lasts less than 30 minutes. Morning stiffness that lasts much longer can point to a different kind of arthritis, so mention it to your clinician.

Treatment depends on how bad the symptoms are. Mild cases are often managed with exercise, weight loss and suitable footwear. Painkillers, and a structured exercise plan with a physical therapist, are added for more severe symptoms. Surgery, including joint replacement, is considered when other treatments have not helped or the joint is badly damaged.

Common myths

  • Myth: moving a sore knee will wear it out. Fact: regular activity is part of the standard advice for osteoarthritis.
  • Myth: a supplement will rebuild the cartilage. Fact: the WHO reports that most guidelines find glucosamine ineffective for osteoarthritis.
  • Myth: everyone with knee pain needs a scan. Fact: the NHS says X-rays and blood tests are not usually necessary for osteoarthritis and are used to rule out other causes.

When to see a doctor, and red flags

Book an appointment if the pain does not improve within a few weeks, the knee keeps swelling, it feels unstable or gives way, or pain wakes you at night. Bring notes on when it started, where it hurts, what makes it worse and what you have tried.

Red flags: go to urgent care, or call 911 for severe symptoms, if the knee is very painful, you cannot move it or put any weight on it, it is badly swollen or has changed shape, it locks, or you have a very high temperature with redness or heat around the knee, which can signal infection.

How a clinician finds the cause

A clinician usually begins with your history and an exam of the joint. Imaging such as an X-ray or MRI can be used when the cause is unclear, after an injury, or to rule out other conditions. Treatment depends on the cause and can include rehabilitation exercises, mobility aids, and in some cases surgery such as arthroscopy or knee replacement.

Questions and answers

Can I walk on a painful knee?

Gentle everyday walking is usually fine if it does not cause sharp pain. If you cannot put weight on the leg at all, you need to be seen the same day.

Is a clicking knee a sign of arthritis?

Not by itself. The NHS describes painless clicking as normal and says to get checked if the click is painful or the knee locks.

Do glucosamine supplements help?

The WHO says most guidelines find glucosamine ineffective for osteoarthritis. Exercise and weight management are better supported.

How long should I wait before seeing someone?

The NHS advises seeing a clinician if knee pain does not improve within a few weeks. Go sooner if you have the warning signs above.

Could knee pain need surgery?

Sometimes. It is usually considered after other treatments fail or when the joint is badly damaged, and the right option depends on the cause.

Sources

  1. NHS — Knee pain
  2. MedlinePlus — Knee Injuries and Disorders
  3. NHS — Osteoarthritis
  4. WHO — Osteoarthritis
  5. NIAMS — Osteoarthritis

Sources checked on 29 October 2026.

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