What are the common causes of knee swelling?

Knee swelling is common and can arise from different causes. Some common reasons include:

• Injury: When you hurt your knee, like twisting it or falling, you might tear a ligament or the meniscus (the cushioning tissue in your knee). This can cause blood and fluid to build up inside the joint, leading to swelling.
• Arthritis: Osteoarthritis (wear and tear of the joint) or inflammatory arthritis like rheumatoid arthritis can inflame the knee. When the joint lining gets inflamed, excess fluid forms, causing the knee to swell.
• Infections: Sometimes, bacteria can infect the knee joint, which is called septic arthritis. This type of inflammation usually comes with pain, redness, and warmth around the knee.
• Other causes: Conditions like gout or pseudogout, which are caused by crystals forming in the joint, can also lead to swelling. Chronic knee problems might also stem from less obvious sources, as noted in clinical studies of adults and adolescents.

Overall, the underlying cause of knee swelling is important to identify so that the right treatment can be given. If you notice swelling in your knee, you can use Ubie's free symptom checker to help understand possible causes before visiting a healthcare provider to find out how to manage it.