Symptoms A-Z

Knee Stiffness Symptoms, Causes & Common Questions

Understand your knee stiffness symptoms, including 8 causes & common questions.

Knee Stiffness Symptom Checker

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Knee Stiffness Symptoms

The knee is the largest and most stressed joint in the entire human body. It is a complex system of bones, cartilage, ligaments, tendons and muscles responsible for weight-bearing and movement. The knees are used for every movement walking, stepping, sitting, and even standing as a result, the knee is susceptible to various conditions that can cause knee stiffness symptoms and discomfort.

Most people, regardless of age, experience knee stiffness symptoms and discomfort at some point in their lives. In fact, knee pain accounts for one-third of musculoskeletal complaints to primary care providers in the U.S. [1]. Older individuals may experience knee pain and discomfort due to multiple age-related conditions, and younger individuals may experience similar symptoms due to sports or other physical activities.

Common accompanying symptoms of knee stiffness

Regardless of the cause, you may also experience other symptoms in addition to knee stiffness symptoms:

Usually stiffness in the knee is easily treated and not a sign of serious injury. However, knee stiffness symptoms can be associated with trauma and severe damage.

Other common symptoms that accompany knee stiffness or injury

You may also experience the following if you have injured your knee.

  • Inability to bear weight on the knee
  • Sensation of instability: Or "giving out" of the knee
  • Popping noises upon movement
  • Visible deformity

If you notice stiffness in the knee and any of these associated symptoms, make an appointment with your doctor promptly.

Knee Stiffness Causes

Stiffness in the knee happens due to inflammation or injury to the components of the knee [2]. Knee stiffness is always the result of an underlying problem and should always be seen by a physician.

Knee structure

See this image for a visual representation of the many components of the knee and how they connect and work together. The components of the knee include:

  • Bones: The femur (thigh bone), patella (kneecap) and tibia (shin bone). The actual knee joint works to keep these bones securely in place.
  • Cartilage: The meniscal and articular cartilage act as cushions around the bones that reduce friction during movement and help the bones move smoothly against each other. There is a medial meniscus on the inner side of the knee and a lateral meniscus on the outer side of the knee.
  • Ligaments: The knee has four ligaments that connect bones to other bones and promote stability: collateral, lateral collateral, posterior cruciate and anterior cruciate ligaments. These ligaments prevent the side to side movement of the femur as well as excessive backward and forward movement of the femur and tibia.
  • Tendons: Tendons are like ligaments but connect bone to muscle (instead of bone to bone). The patellar tendon is the largest tendon of the knee and attaches the quadriceps to the patella and then the patella to the tibia.
  • Fluid: The joint capsule and bursa are fluid filled membranes that lubricate the joint and reduce friction.

Traumatic causes

Stiffness after trauma may be difficult to recognize due to the pain that accompanies traumatic knee events. Usually these knee injuries are not subtle, but in the case that they are, stiffness may be the first symptom.

  • Fracture: A fracture is defined as a broken bone. Patella (kneecap) fractures are most common and are usually the result of a direct, hard blow or a fall, especially in older patients.
  • Sprain: A sprain is defined as a twisting or stretching of a ligament. Any of the four knee ligaments can be sprained in activities that causes bending, twisting, sudden movement, or direct impact. Sports that are often associated with ligament sprain include football, skiing, soccer, and rugby.

Inflammatory causes

Knee stiffness may be a result of inflammation due to the following.

  • Arthritis: Arthritis is a general term for multiple conditions that cause painful inflammation and stiffness of the bones and joints. Arthritis can affect the bones and fluid-filled areas of the knee resulting in significant irritation that can cause chronic stiffness, discomfort, and pain [3].

  • Infection: Inflammation in the knee due to infection is rare but can occur when bacteria enter the knee via a cut or other incision. The fluid-filled bursae and joint capsule can become infected and inflamed [4]. Sometimes, stiffness in an infected knee is also difficult to recognize because this cause is usually more associated with excruciating pain that makes even tiny movements of the knee unbearable.

Environmental causes

Environmental causes may be related to lifestyle or movement habits.

  • Exercise-induced: Muscles that are over-worked without proper conditioning and stretching can become tight and weak. This can make all parts of the leg, including the knee, feel stiff.
  • Positional: Exercise can cause knee stiffness symptoms but being sedentary can lead to stiffness as well. Situations such as long flights or desk jobs in which you are sitting for prolonged periods of time can result in stiff knees.

8 Possible Knee Stiffness Conditions

The list below shows results from the use of our quiz by Buoy users who experienced knee stiffness. This list does not constitute medical advice and may not accurately represent what you have.

Knee arthritis

Arthritis is inflammation of one or more of the joints. Pain, swelling, and stiffness are the primary symptoms of arthritis. Any joint in the body may be affected by the disease, but it is particularly common in the knee.

Rarity: Common

Top Symptoms: pain in both knees, knee stiffness, knee instability, swollen knee, morning joint stiffness

Symptoms that always occur with knee arthritis: pain in both knees

Urgency: Primary care doctor

Jumper's knee (patellar tendonitis)

Jumper's knee is also called patellar tendinitis or patellar tendinopathy. It is an inflammation of the patellar tendon, which runs from the bottom of the patella – or kneecap – to the top of the shinbone.

It is most often an overuse injury seen in athletes, especially those in sports involving jumping, but it can affect anyone. Strenuous physical activity without warming up first, or tightness and inflexibility in the muscles of the thighs, can put additional strain on the patellar tendon.

Symptoms include pain just below the kneecap. At first it may only appear during exercise, but later becomes chronic as the tendon becomes more damaged and inflamed. Eventually the pain interferes with normal movement.

It is important to get treatment, as the condition will not heal on its own and will only get worse through forced movement.

Diagnosis is made through patient history, physical examination, and imaging such as ultrasound or x-ray.

Treatment involves rest; pain relievers; physical therapy to return flexibility to the tendon; and sometimes corticosteroid injections or surgery.

Rarity: Rare

Top Symptoms: pain in one knee, spontaneous knee pain, knee pain that gets worse when going up stairs, knee stiffness, knee pain that gets worse when squatting

Urgency: Primary care doctor

Osteochondritis dissecans

Osteochondritis dissecans, also called OCD, is a joint condition. It occurs when there is not enough blood flow within the end of a bone, under the protective cartilage. These bone layers begin to die and separate from the main bone, taking the cartilage with them.

The exact cause is not known. It may be due to overtraining a young person before the bone is entirely mature, which can interfere with blood supply.

Most susceptible are children and teenagers. The condition is found most often in only one joint, usually the ankle, knee, or elbow. However, any joint can be affected and there may be more than one.

Symptoms include swelling and pain in the joint during exercise, and sometimes "locking" of the joint. Osteochondritis dissecans may lead to osteoarthritis if not treated.

Diagnosis is made through patient history, physical examination, and imaging.

Treatment first involves rest because in children who are still growing, the bone and cartilage may heal spontaneously. If there are loose pieces of bone within a joint, surgery may be necessary.

Rarity: Rare

Top Symptoms: pain in one knee, knee stiffness, knee instability, knee pain that gets worse during a run, pop in the knee

Urgency: Primary care doctor

Meniscal injury

The menisci are the two pieces of cartilage serving as shock absorbers in the knee, between the lower end of the thighbone and the top of the shinbone. A torn meniscus is commonly referred to as "torn cartilage" in the knee.

Damage to a meniscus often happens along with another injury to the knee, especially when there is any forceful, twisting movement or a direct hit such as a tackle.

Older people may tear a meniscus through normal activity if the cartilage has become thin and worn due to aging.

Symptoms include pain, stiffness, and swelling. The knee will simply not work correctly and may catch, lock up, or give way.

Diagnosis is made through patient history, physical examination, simple motion tests, and imaging such as x-ray or MRI.

Depending on the exact form of the injury, the tear may be allowed to heal on its own with supportive care such as rest, ice, and nonsteroidal anti-inflammatory pain medication. In other cases, arthroscopic surgery followed by rehabilitation may be needed.

Rarity: Common

Top Symptoms: pain in one knee, knee stiffness, knee instability, pain in the inside of the knee, swollen knee

Urgency: Primary care doctor

Knee Stiffness Symptom Checker

Take a quiz to find out what might be causing your knee stiffness

Rheumatoid arthritis

Arthritis is a general term for multiple conditions that cause painful inflammation and stiffness throughout the body. Rheumatoid arthritis (RA) is a chronic condition that is autoimmune in nature, meaning that the body's immune system which normally protects the body by att...

Psoriatic arthritis

Psoriatic arthritis is a condition which causes inflammation of the joints. In most circumstances, psoriatic arthritis presents between the ages of 30 and 50 years and occurs after the manifestation of the symptoms of psoriasis, which is a disease of the skin. Psoriatic arthritis...

Septic arthritis

Septic arthritis is also called infectious arthritis. "Arthritis" simply means inflammation of a joint. In septic arthritis, the inflammation is caused by a bacterial, viral, or fungal infection. The most common is Staphylococcus aureus or staph. These agents reach the joints either from ...

Lupus

Lupus is an inflammatory autoimmune disease that happens when the body's immune system mistakenly attacks its own cells, tissues, and organs. Lupus is also a systemic disease and can affect multiple body systems including the heart, lungs, joints and even skin.

Since lupus can affect multiple organ systems, symptoms can...

Knee Stiffness Treatments and Relief

At-home treatments

Treatment for knee stiffness often starts at home with simple lifestyle changes. The RICE (Rest, Ice, Compress, Elevate) mnemonic is an often-used, guide for treating stiffness and swelling of the knee:

  • Rest: Limit weight-bearing of the affected knee or knees as much as possible. Your doctor may suggest crutches.
  • Ice: Put an ice pack on your knee or place your knee in ice water every 15 minutes in order to reduce any swelling.
  • Compression: Protect your knee from unnecessary movement by using a stretchy bandage or compression wrap with a protective brace. Compression like this can also help with swelling.
  • Elevation: Raising your leg and knee above the level of your heart can also help reduce swelling and bruising.

If you find yourself sedentary for many hours of the day, like during work, for example, prevent knee stiffness by getting up to move every 30 minutes or so to help lubricate the knee.

However, if your knee stiffness symptoms are persistent or associated with any of the red-flag symptoms above, seek prompt medical attention.

When to see a doctor

If your knee stiffness is persistent and at-home treatments do not provide relief, you should see your physician. He or she may suggest:

  • Physical therapy: After many knee injuries, your doctor will suggest physical therapy in order to restore range of motion, strength and stability to your knee.
  • Medication: If your severe knee pain is due to inflammatory conditions, your doctor may prescribe antibiotics to treat an infection or anti-inflammatory medications to treat arthritic conditions.
  • Surgery: Fractures and tears of the ligaments and cartilage of the knee often require surgical intervention.

Questions Your Doctor May Ask About Knee Stiffness

To diagnose this condition, your doctor would likely ask the following questions:

  • Do you feel like your knee is unstable, weak, or giving out?
  • Do you feel like your knee is locking from time to time?
  • What is your body mass?
  • Do you often feel your knees buckling?

The above questions are also covered by our A.I. Health Assistant.

If you've answered yes to one or more of these questions

Take a quiz to find out what might be causing your knee stiffness

Knee Stiffness Symptom Checker Statistics

People who have experienced knee stiffness have also experienced:

  • 18% Knee Pain
  • 6% Knee Locking
  • 6% Knee That Clicks During Movement

People who have experienced knee stiffness were most often matched with:

  • 33% Knee Arthritis
  • 33% Jumper'S Knee (Patellar Tendonitis)
  • 33% Osteochondritis Dissecans

People who have experienced knee stiffness had symptoms persist for:

  • 39% Over a month
  • 20% Less than a week
  • 18% Less than a day

Source: Aggregated and anonymized results from visits to the Buoy AI health assistant (check it out by clicking on “Take Quiz”).

Knee Stiffness Symptom Checker

Take a quiz to find out what might be causing your knee stiffness

References

  1. Calmbach WL, Hutchens M. Evaluation of Patients Presenting with Knee Pain: Part I. History, Physical Examination, Radiographs, and Laboratory Tests. American Family Physician. 2003;68(5):907-912. AAFP Link
  2. Common Knee Injuries. American Academy of Orthopaedic Surgeons: OrthoInfo. Updated March 2014. OrthoInfo Link
  3. Arthritis and Diseases That Affect the Knee. Arthritis Foundation. Arthritis Foundation Link
  4. Chatra PS. Bursae Around the Knee Joints. The Indian Journal of Radiology & Imaging. 2012;22(1):27-30. NCBI Link
  5. Leopold SS. Osteoarthritis of the Knee. UW Medicine: Orthopaedics and Sports Medicine. Updated February 14, 2011. UW Medicine Link

Disclaimer: The article does not replace an evaluation by a physician. Information on this page is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes.