Knee Osteoarthritis: Patient Guide to Symptoms, Treatment & Management

Overview

Knee osteoarthritis (OA) is the most common form of arthritis, a degenerative condition where the smooth, protective cartilage that cushions the bones in your knee joint wears down over time. As cartilage breaks down, bones rub against each other, causing pain, stiffness, swelling, and reduced mobility. It affects more than 32 million adults in the U.S. alone, and is a leading cause of disability in older adults, though it can occur at any age, especially after a knee injury. OA is a progressive condition, meaning symptoms tend to worsen over time if not managed. While there is no cure, early intervention and consistent symptom management can slow progression, reduce pain, and help you maintain an active, independent life for years.

Signs & Symptoms

Knee OA symptoms develop gradually and may be mild at first, worsening over months or years. Common signs include:

• Pain that worsens with activity (walking, climbing stairs, standing up from a chair) and improves with rest
• Stiffness in the knee after periods of inactivity, especially first thing in the morning or after sitting for a long time (usually lasts less than 30 minutes)
• Swelling around the knee, which may feel warm to the touch
• A grating, grinding, or crackling sensation (called crepitus) when moving the knee
• Reduced range of motion, making it hard to fully bend or straighten the knee
• Knee instability, buckling, or giving way, especially when walking

Causes & Risk Factors

Knee OA has two main categories of causes: primary (age-related wear and tear) and secondary (caused by a specific injury or underlying condition). The most common risk factors include:

• Age: Risk increases significantly after age 45, as cartilage naturally breaks down over time
• Previous knee injury: Torn ligaments, meniscus tears, or knee fractures increase OA risk later in life
• Obesity: Extra body weight puts added pressure on knee joints, accelerating cartilage wear; fat tissue also produces proteins that cause joint inflammation
• Family history: Genetics play a role in OA risk, so you are more likely to develop it if a close family member has the condition
• Repetitive knee stress: Jobs or sports that involve frequent kneeling, squatting, or heavy lifting increase risk
• Muscle weakness: Weak quadriceps (thigh muscles) or hip muscles reduce knee stability and increase joint stress

Diagnosis

There is no single test for knee OA. Your healthcare provider will diagnose it based on your medical history, a physical exam of your knee, and imaging tests to confirm the diagnosis and rule out other causes of knee pain, such as gout, rheumatoid arthritis, or a meniscus tear.

Treatment & Management

There is no cure for knee OA, but treatment focuses on reducing pain, improving joint function, slowing disease progression, and helping you maintain your quality of life. Treatment plans are tailored to the severity of your condition and your individual needs.

• Lifestyle modifications: Weight loss (if overweight) and low-impact exercise are first-line treatments for most people with knee OA
• Physical therapy: A therapist can teach you exercises to strengthen knee and hip muscles, improve flexibility, and reduce joint stress
• Pain relief: Over-the-counter options like acetaminophen, topical NSAIDs, or ice/heat therapy can relieve mild to moderate pain
• Assistive devices: Canes, crutches, or knee braces reduce pressure on the knee joint during activity and improve stability

For moderate to severe OA that does not improve with first-line treatments, your provider may recommend prescription pain medications, corticosteroid or hyaluronic acid injections to reduce inflammation, or surgical options including arthroscopy, osteotomy, or knee replacement. To live well with knee OA long-term, maintain a healthy weight, stay active with low-impact exercise, pace your daily activities to avoid overloading your knee, and work with your care team to adjust your management plan as your symptoms change.