The knee is the largest joint in the body and bears a multiple of body weight with every step — no wonder knee pain is one of the most common complaints of the musculoskeletal system. The range is wide: from overuse after unaccustomed activity to injuries of the meniscus and ligaments to age-related joint wear. Exactly where it hurts, since when, and under which load, often already provides the decisive clue to the cause — and to how urgent an assessment is.
Possible causes
Overuse and irritation
The most common cause: after unaccustomed exertion, prolonged stair climbing, hiking, or sport. Typical are exertion-related pains that ease again at rest. This usually heals by itself with a little rest.
Wear and tear (osteoarthritis)
Age-related breakdown of joint cartilage. The pain is load-dependent, and the knee stiffens briefly in the morning or after prolonged sitting ('start-up pain'). Osteoarthritis cannot be reversed, but can be kept well under control with targeted measures.
Meniscus or ligament injury
Usually after a twisting motion or a fall, frequently during sports. Signs are rapid swelling, a feeling of instability, or a blockage where the knee can no longer fully extend.
Inflammatory rheumatic cause
If not just the knee but several joints are affected, if it is stiff for longer in the morning and the complaints persist for weeks, an inflammatory rheumatic disease may be the underlying cause. This should be evaluated by a rheumatologist.
Typical steps at the doctor's office
- 1The doctor will first ask in detail where and since when it hurts, what triggered it, and whether your knee swells, locks or gives way. This is followed by a physical examination of mobility, stability and pressure points — this already provides a large part of the diagnosis.
- 2Depending on the suspected cause, imaging may be added: ultrasound shows soft tissue and effusions, X-ray shows bone and joint space, and MRI shows meniscus and ligaments in detail if needed. Not every knee needs an MRI right away.
- 3Treatment depends on the cause and almost always begins conservatively: targeted physiotherapy to strengthen the stabilizing muscles, temporary relief and — if needed and as prescribed by your doctor — anti-inflammatory medication. Surgery is only considered for certain injuries or advanced wear.
What you can do yourself
- In the acute phase: relieve your knee moderately, apply ice and elevate it — but do not immobilize it completely; movement within the pain-free range is good for the joint.
- Strengthen your thigh muscles: strong muscles noticeably relieve the knee joint and are the most effective long-term measure.
- Focus on joint-friendly movement — cycling and swimming put less stress on the knee than jogging on hard surfaces.
- Reduce excess weight where possible: every kilogram less relieves your knee several times over with each step.
A visit to the doctor is advisable if the pain lasts longer than one to two weeks, keeps returning, the knee is swollen, locks up or gives way, or if it restricts you in daily life and when sleeping. After an accident with immediate severe swelling or instability, you should have it checked the same day.
Frequently asked questions
- Should I rest my knee or move it?
- Both in moderation. Short-term relief for acute pain is right, but complete immobilization is harmful. Movement within the pain-free range and targeted strengthening are the best medicine for most knee problems.
- Do I need an MRI?
- Not automatically. An MRI makes sense if a meniscus or ligament injury is suspected or in cases of unclear progression — for many knee complaints, consultation, examination and ultrasound or X-ray are sufficient.
- Which doctor should I see?
- For load-related or wear-related pain, see an orthopedist. If several joints are affected and stiff for longer in the morning, rheumatology is responsible. When in doubt, your general practitioner will assess and refer you accordingly.
Not sure whether you should go or whom to see? Describe your symptoms — we'll find the right practice in your area.