In most but not all cases, the symptoms of knee osteoarthritis come and go, becoming worse and more frequent over months or years. It is easy to dismiss early knee arthritis symptoms, but symptoms may worsen if left untreated.
The most commonly reported symptom of knee osteoarthritis is knee pain. The description of the pain will depend on the person’s condition and situation. For example, the pain may come and go or there may be a chronic low level of pain with intermittent flare-ups of more intense pain. The pain may be experienced as dull and aching or as sharp and intense.
Knee arthritis pain usually gets worse with certain activities that place additional strain on the joint, such as when squatting or walking up stairs. Typically, the knee pain can be lessened with rest and an ice compress.
Exactly how knee osteoarthritis causes pain is unknown and seems to vary from person to person.1
Other Symptoms of Knee Osteoarthritis
In addition to knee pain, people with knee arthritis often report one or more of the following symptoms:
When knee cartilage wears away, the femur and tibia (and sometimes patella) bones can rub together, resulting in irritation. Sometimes this irritation leads to the production of excess joint fluid, resulting in knee swelling.
Bone-on-bone friction and knee joint swelling makes the knee feel stiff. Some people may only experience knee stiffness for about 30 minutes in the morning or after sitting for a long period. Stiffness may or may not be accompanied by visible swelling or a reduced range of motion.
Redness and warmth
The skin over the knee may become red and warm. These signs could also indicate an infection, which requires immediate medical attention. People who are uncertain of the underlying cause of knee redness and warmth, particularly when accompanied by swelling, are advised to seek immediate medical attention.
Reduced range of motion
The knee’s range of motion may become limited, making it less flexible. For example, moderate to advanced knee osteoarthritis may make it difficult to completely bend or straighten the knee.
Worsening symptoms with inactivity
Knees can become stiff after sleeping or sitting for a long period of time. People with knee osteoarthritis often find stiffness and pain are most noticeable when they try to get out of bed in the morning or out of a chair after a long period of sitting.
Popping or crunching
Feeling or hearing crunching or popping when bending the knee, such as when bending down into a squat, are signs of knee joint friction. The medical term for this symptom is crepitus. (Crepitus by itself without other symptoms is not a cause for concern.)
Buckling or locking up
Moderate to advanced knee osteoarthritis can cause the sensation of a knee giving way or buckling. This sensation can occur if uneven grooves or flaps in the degenerated cartilage catch or if a piece of cartilage breaks off and becomes lodged in the joint. Knee locking or buckling is also typical in people who have a ligament injury or meniscus tear.
Watch: Knee Meniscus Tear Video
The symptoms and signs of knee osteoarthritis most often come on gradually. Sudden knee pain is more likely to be caused by trauma or another condition, such as pseudogout. Knee osteoarthritis may be dormant (i.e. a person may be unaware they have it) and only become symptomatic following a traumatic event or excessive physical activity.
Early recognition of knee osteoarthritis symptoms and signs, and appropriate treatment, can dramatically slow or eliminate the progression of osteoarthritis symptoms.