Symptoms: What Is Knee Pain and What Symptoms Can Occur?
Knee pain refers to any pain around the knee joint – one of the most complex and heavily loaded joints in our body. Nearly everyone experiences knee pain at some point, from athletic teenagers to seniors. This is completely normal and no reason to panic.
Typical accompanying symptoms include:
Swelling and stiffness of the knee – the joint feels bloated and immobile
Redness or warmth – the knee feels warm or hot compared to the other side
Weakness or instability – the knee gives way or feels unsafe when walking
Cracking or grinding sounds when moving – audible noises during bending or straightening
Limited range of motion – you can no longer fully straighten or completely bend the knee
The character of pain can vary: sharp, stabbing pain versus dull aching, constant pain versus only with movement. For example: Sharp pain in the front with sudden stress often indicates an acute injury, while dull pain during weather changes is more likely to suggest arthritis.
Knee pain can significantly impact daily life – from problems climbing stairs to nighttime pain that robs you of sleep. You may recognize this experience yourself and know you're not alone in dealing with it.
Causes: Why Does My Knee Hurt? – Possible Causes of Knee Pain
Injuries as Acute Causes
Many knee problems stem from accidents or sports injuries:
Ligament strains or tears: The ACL (anterior cruciate ligament) tear often occurs during sudden twisting movements in sports. Typical signs include an audible pop, knee instability, and significant swelling.
Meniscus tears: The inner or outer meniscus can tear during twisting motions. You'll feel pain when rotating or bending the knee, sometimes with a locking sensation.
Bruises and fractures: A fall or blow to the knee can cause bruising or, in extreme cases, a bone fracture, recognizable by severe pain and inability to stand up.
Mechanical Problems and Overuse
Not all pain comes from a single trauma – sometimes it develops from chronic overuse:
Overuse syndromes develop gradually. Runner's knee (IT band syndrome) causes outer knee pain from an irritated tendon band. Jumper's knee (patellar tendinitis) leads to pain below the kneecap from overuse of the patellar tendon in jumping sports.
Misalignments like knock-knees or bow legs lead to uneven loading. This creates excessive pressure on the inside or outside, leading to pain and cartilage wear over time.
Loose bodies: A small piece of cartilage or bone can break off and "float" in the joint. This causes sporadic sharp pain or locking when it becomes trapped.
Degenerative Causes (Wear and Tear)
With age or heavy use, the knee joint wears down:
Arthritis (gonarthrosis) is cartilage wear in the knee, very common in people over 50. Symptoms include startup pain (morning stiffness, pain after prolonged sitting), pain under load, and occasional grinding sounds. Often both knees are affected, but not symmetrically to the same degree. Arthritis develops gradually and can lead to chronic pain.
Arthritis refers to inflammatory processes. In rheumatoid arthritis (autoimmune inflammation), swelling, warmth, and morning stiffness typically occur, often in both knees. Gout is caused by uric acid crystals in the knee – sudden, very severe pain, red hot knee, usually starting at night with attack-like pain. Infectious arthritis is rare but an emergency: bacterial infection in the joint with severe illness and fever.
Contributing Factors
Often multiple factors work together:
Excess weight: Every extra kilogram affects the knee three to five times more during activity and accelerates wear
Muscle weakness: Weak thigh muscles lead to higher kneecap stress
Occupational stress: Work involving lots of kneeling (construction workers, tile layers) causes pain over years
Stress and tension: Can intensify pain perception – relaxation often helps as part of therapy
Location: Where Does It Hurt & When?
Pain at the Kneecap (Front of Knee)
Front knee pain is very common and often stems from patellofemoral pain syndrome. You feel pain "behind the kneecap" or around it, which often worsens when going DOWN stairs, squatting, or sitting for long periods (the so-called "theater sign").
Possible causes include:
Kneecap misalignment: The kneecap doesn't track properly and irritates the cartilage
Cartilage damage: Chondromalacia or arthritis behind the kneecap
Patellar tendinitis: Patellar tendon inflammation, especially in athletes
Bursitis: From chronic kneeling (housemaid's knee)
Front knee pain often comes on gradually and diffusely but responds well to treatment through physical therapy for muscle strengthening, special braces for kneecap guidance, or anti-inflammatory medications.
Pain on the Inner Side of the Knee (Medial)
Important structures lie on the inner side of the knee: inner meniscus, medial ligament, and muscle attachments from the thigh. Typical are inner-side pains especially when climbing stairs or rising from a squat, as the inner meniscus is heavily stressed during these movements.
Possible causes include:
Inner meniscus tear: Often from twisting, pinpoint inner pain, possibly "snapping" in the joint
Medial ligament strain or tear: For example, in skiing accidents with instability feelings
Arthritis in the inner joint space: Medial gonarthrosis often starts on the inside due to bow-leg stress
Bursitis: On the inner side below the joint from overuse
Inner pain often comes with the feeling that the knee is "wobbly" or gives way during turns.
Pain on the Outer Side of the Knee (Lateral)
The outer meniscus and ligament are located on the outside, plus the iliotibial band (tendon plate from hip bone to shinbone) runs along here. Iliotibial band syndrome is the classic runner's knee: pain on the outside, starting after some running distance, possibly radiating up toward the hip. The cause is friction of the tight band over the bone prominence at the knee.
Other causes include:
Outer meniscus tears: Less common than inner tears, but similar injury mechanisms
Lateral ligament injuries: From sideways force with instability feelings
Outer arthritis: With knock-knees, the outer joint space becomes overloaded
Pain Behind the Knee (Posterior)
Back pain can come from various structures: muscles, tendons, blood vessels, or nerves in the back of the knee. A Baker's cyst is common – a fluid-filled pouch extending from the joint capsule backward. It often occurs with arthritis or meniscus damage and causes a palpable swelling behind the knee with a feeling of tightness.
Other causes are muscle tension (shortened hamstrings), posterior meniscus tears, or rare nerve irritations.
Situations: Knee Pain with Specific Movements and Situations – What's Behind It?
Going Up or Down Stairs
Many report increased knee pain when going downstairs or walking downhill. Multiple times your body weight loads the knee, especially the kneecap. Common problems are patellofemoral pain syndrome (cartilage behind kneecap irritated), knee arthritis, or meniscus damage.
Tip: Temporarily avoid stairs or use a handrail for support; long-term, strengthen muscles.
Squatting/Bending the Knee
Pain when bending deeply can indicate meniscus problems (menisci get compressed with deep bending) or patella problems (kneecap presses hard into the groove). Joint effusion also makes deep squatting painful.
Recommendation: Don't force yourself into a squat; have causes medically evaluated.
Standing Up After Prolonged Sitting (Startup Pain)
You sit for an hour, stand up – the knee is stiff and hurts, after a few steps it gets better. This suggests beginning arthritis (joint fluid must first be "distributed") or plica syndrome.
Here helps: Regularly move the knee while sitting to prevent stiffness.
After Sports/Jogging
Post-exercise pain can indicate overuse or minor damage. Occasional pain after unusual exertion is normal and heals with rest. But if pain follows every run, you should have your gait, shoes, and running style evaluated.
At Night/During Rest
Nighttime knee pain is a warning sign. Causes are often inflammation (arthritis, activated osteoarthritis) or advanced arthritis. Pain that wakes you at night or persists at rest should be medically examined.
With Weather Changes
Some notice their knee hurts more in damp, cold weather. This likely relates to pressure and temperature changes affecting the joint capsule and nerve endings. Here helps: Keep knees warm; movement promotes circulation.
Diagnosis: How Is the Cause of Knee Pain Determined?
Doctor Visit – Medical History
The first step is a thorough conversation. The doctor asks: How long have the pains existed, where exactly, what's the pain like (stabbing/dull), specific triggers, was there an accident? Accompanying symptoms like swelling, fever, or instability are also important. The more precisely you can describe this, the better.
Physical Examination
The orthopedist will look at and feel your knee: detect swelling, test mobility, locate pressure-sensitive points. Special tests can irritate the meniscus (through specific bending/rotating movements) or test the cruciate ligaments (stability tests). Through such maneuvers, the doctor can often assess which structure is injured.
Imaging
X-rays show bones and are good for detecting arthritis (narrowed joint space) or bony injuries.
Ultrasound can show fluid (effusion), ligament tears, or Baker's cysts. Advantage: no radiation, possible directly in the office.
MRI (magnetic resonance imaging) is very important for soft tissues and shows meniscus, cruciate ligament, and cartilage damage precisely. Used when such injuries are suspected or when X-ray was normal but pain is severe.
Additional Tests
When inflammatory causes are suspected, blood tests are done (inflammatory markers, rheumatoid factors, uric acid for gout). Sometimes joint fluid is withdrawn for examination.
The doctor combines all information for diagnosis. Sometimes it's clear, sometimes complex. Don't hesitate to seek a second opinion for unclear diagnoses, especially before major surgeries.
Treatment & Therapy: What Can You Do About Knee Pain?
What Can You Do About Knee Pain Yourself?
RICE Protocol for Acute Pain
For sudden knee pain after injury: Rest, Ice, Compression, Elevation. Rest the knee, cool it (ice pack 15-20 minutes every 2-3 hours), apply an elastic bandage (not too tight), and elevate the leg. These measures reduce pain and damage in the first 48 hours.
Relief and Protection
With knee pain, reduce loading. Don't continue walking on the painful knee. Possibly use crutches temporarily, but don't remain in a protective posture for weeks (leads to muscle wasting). It's a balancing act: acute pain needs rest, chronic pain needs movement.
Cold vs. Heat
Rule of thumb: For acute injuries and inflammation, cool (reduces swelling and numbs pain). For chronic tension or arthritis, heat often helps (promotes circulation, relaxes muscles). Is the knee swollen and hot → cooling! Does it feel stiff but not swollen → heating pad.
Ointments and Home Remedies
Over-the-counter pain gels (with diclofenac or ibuprofen) can provide relief for superficial pain. Plant-based ointments like arnica gel or comfrey ointment have mild effects. Quark wraps are time-tested against swelling – cooled quark on a cloth, around the knee, 15-20 minutes.
Pain Medications
For severe pain, NSAIDs like ibuprofen, diclofenac, or naproxen can help – they work as painkillers and anti-inflammatories. For stomach problems, acetaminophen is an alternative. Important: Take these medications only according to package instructions and not longer than a few days without medical advice.
Aids
A knee brace can give the joint support and warmth, which often subjectively reduces pain. Stable shoes with cushioning relieve the knee. A walking stick on the opposite side can reduce loading by about 20% with severe pain.
How Is Knee Pain Treated Medically?
Physical Therapy and Exercise
The foundation of almost every treatment. Physical therapy has several goals: muscle building (especially front thigh and hip muscles stabilize the knee), stretching shortened muscles, and coordination training. A good physical therapist first relieves pain and then works with you on exercises for home.
Medication Therapy
Pain and anti-inflammatory drugs: NSAIDs also possible long-term in low doses, but beware of side effects (stomach protection with longer use).
Cortisone: For severe inflammation, the doctor can give a cortisone injection into the joint. This often dramatically reduces inflammation and pain, but only temporarily.
Hyaluronic acid injection: Often used for arthritis to "refill" joint fluid. Study evidence is mixed – some patients benefit, others barely.
Aids
Special knee orthoses depending on the problem: Hinged braces after ACL tear, unloader orthoses for arthritis (relieve one side of the knee joint), patella braces with cutouts. Orthopedic shoe inserts for misalignments help correct the axis and better distribute knee loading.
Surgical Interventions
Arthroscopy (joint endoscopy): For meniscus tears or loose bodies, keyhole surgery is often performed. Advantages: small incisions, short rehab.
ACL reconstruction: For ACL tears in athletically active patients, a tendon transplant is usually inserted. 6-9 months rehab.
Partial knee replacement: When only one area is arthritically destroyed, half a prosthesis is inserted.
Total knee replacement: For severely advanced arthritis, the knee joint is replaced with metal-plastic parts. Durability about 15-20 years.
Consistent rehabilitation follows every surgery.
Prevention: What Can You Do to Prevent Knee Pain?
Stay Active, But Joint-Friendly
Exercise is essential for healthy knees. Recommendation: regular moderate exercise instead of sporadic overexertion. For example, daily walks instead of 12 miles of jogging once a week.
Choose Suitable Sports
Knee-friendly activities include swimming, cycling, Nordic walking, regular walking, and yoga/Pilates. Sports with abrupt stops and turns (soccer, tennis) or jumps are more stressful – don't avoid them, but pay attention to proper warm-up and technique.
Muscle Training and Stretching
Strong muscles protect joints. Especially quadriceps and hip muscles support the knee. Include strength exercises 2-3 times a week. At the same time, stretch shortened muscles – especially front and back thigh, calves.
Weight Control
Every kilogram less significantly relieves the knee. Even 11 pounds of excess weight significantly increases arthritis risk. Studies show: in overweight people with arthritis, even 10% weight loss improves pain and function.
Good Shoes and Ergonomics
Wear shoes with cushioning and stability. No high heels in daily life. Knee pads for work requiring lots of kneeling. Lift heavy loads correctly (from the knees with straight back).
10 Tips for Healthy Knees:
Daily movement, moderate loading
Knee-friendly sports (swimming, cycling)
Lift heavy loads with straight back from the knees
Avoid deep squats under very high load
Stretch legs while sitting intermittently
Don't stand or squat too long – change position
Cushioned footwear when walking/standing a lot
Flat shoes instead of high heels in daily life
Lose excess weight – every kilogram counts
Regularly strengthen and stretch leg muscles
Red Flags: When Should You See a Doctor for Knee Pain?
See a Doctor Immediately If:
Persistent pain over 3-5 days despite rest
Significant swelling or movement blockade (knee can no longer be fully straightened/bent)
Instability – the knee gives way or feels unsafe
Pain even at rest or at night (warning sign for inflammation)
Deformity after accident – knee looks "dislocated"
Fever, redness, severe effusion – suspected infection (emergency!)
Open injuries or bruising after trauma
Very severe pain that makes movement impossible
Numbness in the leg (could indicate nerve damage)
When in doubt: Better to see a doctor once too early than too late. Especially with sports injuries, early diagnosis is important.
Emergency 911: For suspected vascular injury (cold foot, no pulse felt) or if you can't get away from the accident site at all.
Frequently Asked Questions About Knee Pain
What can you do about knee pain if you don't want to go to the doctor?
You can initially try rest, cooling for acute pain or heat for chronic complaints, and over-the-counter pain ointments/tablets. Braces can also help. Important: If pain doesn't improve after several days, you can't avoid a doctor visit – only they can determine the exact cause.
How do I know if my meniscus or cruciate ligament is injured?
With a meniscus tear, you often have sharp, pinpoint pain in the joint, especially when turning or squatting. Sometimes the knee "locks." An ACL tear usually happens through trauma – you may hear/feel a pop, the knee swells significantly and feels unstable. Only a doctor can distinguish precisely with special tests.
Is heat or cold better for knee pain?
That depends on the situation. Acute injuries or inflammation – always cold. Chronic, non-inflammatory pain – heat is fine. Remember: Hot, swollen knee never heat! When unsure, rather cool.
Can I continue sports with knee pain?
With an acute injury, you should pause. With chronic pain, moderate exercise is actually beneficial. Choose joint-friendly sports and listen to your body: mild pain the next day is okay, severe pain means overexertion.
Which pain medications are best for knee pain?
Usually NSAIDs like ibuprofen, diclofenac, or naproxen are used. They help against pain and inflammation. Acetaminophen can relieve pain but has no anti-inflammatory effect. Important: Take these medications only temporarily – they fight symptoms, not the cause.
Does knee arthritis always require surgery?
No, not always. Treatment is staged: weight reduction, physical therapy, appropriate shoes/inserts, and pain medication as needed. Surgery is only considered when conservative measures no longer provide adequate relief and pain is severe.
Can I have knee damage without feeling pain?
Yes – there are people with severe arthritis on X-ray but hardly any pain. Conversely, moderate damage can cause severe pain. Specifically, meniscus tears or cartilage damage can remain asymptomatic for a long time. The knee has a certain "buffer potential." Pain is an important indicator, but only a doctor can determine the extent of damage through examination and imaging. Don't panic with occasional cracking or brief pain – it doesn't always mean something serious.
