Osteoarthritis is a degenerative joint disease that commonly affects the knee joint. The symptoms of knee osteoarthritis can vary in severity, and they often develop gradually over time. Common symptoms include:

1. **Pain:** Pain is a hallmark symptom of knee osteoarthritis. It typically occurs during or after activity, but it can also be present at rest, especially during periods of prolonged inactivity.

2. **Stiffness:** Stiffness in the knee joint, especially after periods of inactivity like sitting or sleeping, is a common symptom. The stiffness tends to improve with movement.

3. **Swelling:** Inflammation within the knee joint can lead to swelling. The affected knee may appear larger or feel puffy.

4. **Limited Range of Motion:** As osteoarthritis progresses, the range of motion in the knee may become limited. This can make it difficult to fully straighten or bend the knee.

5. **Joint Crepitus:** Osteoarthritis can cause a crackling or grating sensation in the knee joint, known as crepitus. This can be felt or heard when moving the knee.

6. **Weakness:** Muscular weakness around the knee joint may develop, affecting the ability to bear weight or perform certain activities.

7. **Instability:** The knee may feel less stable, and individuals may experience a sense of giving way or buckling, particularly during weight-bearing activities.

It’s important to note that the symptoms of knee osteoarthritis can vary from person to person, and not everyone with osteoarthritis will experience all of these symptoms. Additionally, other conditions, such as rheumatoid arthritis or meniscal injuries, can cause similar symptoms, so a healthcare professional should be consulted for an accurate diagnosis and appropriate management.