Cause

Osteoarthritis occurs when changes in cartilage cause the cartilage to break down faster than the body can produce it. When cartilage breaks down, the bones rub together and cause damage and pain. Experts don't know why this happens. But things like aging, joint injury, being overweight, and genetics may increase your risk.

In some cases, arthritis is caused by other conditions that damage cartilage.

Symptoms

Symptoms of osteoarthritis can range from mild to severe.

They may include:

• Pain. Your joints may ache, or the pain may feel burning or sharp. For some people, the pain may come and go. Constant pain or pain while you sleep may be a sign that your arthritis is getting worse.
• Stiffness. When you have arthritis, getting up in the morning can be hard. Your joints may feel stiff and creaky for a short time, until you get moving. You may also get stiff from sitting.
• Muscle weakness. The muscles around the joint may get weaker. This happens a lot with arthritis in the knee.
• Swelling. Arthritis can cause swelling in joints, making them feel tender and sore.
• Deformed joints. Joints can start to look like they are the wrong shape, especially as arthritis gets worse.
• Reduced range of motion and loss of use of the joint. As your arthritis gets worse, you may not be able to fully bend, flex, or extend your joints. Or you may not be able to use them at all.
• Cracking and creaking. Your joints may make crunching, creaking sounds. This creaking may also occur in a normal joint. But in most cases, it doesn't hurt and doesn't mean that there is anything wrong with the joint.

Arthritis of the spine can also narrow the openings that make space for the spinal cord and for the nerves that branch off the spinal cord (spinal nerves). This is called spinal stenosis. It can lead to pressure on the spinal cord or spinal nerves. This pressure can cause pain, weakness, or numbness.

Some medical conditions can cause symptoms similar to osteoarthritis.

• Compare osteoarthritis and rheumatoid arthritis.
• Learn about other conditions with symptoms similar to osteoarthritis.