Arthritis can cause pain and inflammation in any joint in your body, but it’s especially common in the knee joints. Swelling, stiffness, and pain can prevent you from doing daily activities, including walking for long distances and going up and down stairs.

There are many different forms of arthritis. Each causes pain and discomfort, and in severe cases, disability. The most common types are osteoarthritis and rheumatoid arthritis.

Osteoarthritis happens when the cartilage—the soft tissue between the bones—breaks down. Without this soft tissue, bones rub against each other, causing pain and swelling. This form of arthritis is generally more common in adults 50 and older or people who have had an injury that has damaged a joint.

Rheumatoid arthritis is an autoimmune disorder that causes the immune system to attack healthy tissue in the body. It targets the tissue lining joints, causing the damage to cartilage which leads to arthritis. This, and other types of autoimmune arthritis, can affect people of all ages.

According to the Centers for Disease Control and Prevention, around 52.5 million adults in the U.S. were diagnosed with some form of arthritis each year from 2010 to 2012. It’s also a leading cause of disability, causing work limitations and a higher risk of fall and injury.

Arthritis and knee pain

Your knee joint has three bones that come together: the thighbone (femur), shinbone (tibia), and kneecap (patella). Between these bones are pieces of cartilage, which act as cushions, preventing the bones from touching. A thin membrane surrounds the joint and delivers a fluid to help lubricate the cartilage for smooth movement.

When cartilage tissue is lost and the membrane is damaged, these three bones begin to rub together. The friction creates pain, swelling, and can cause bone spurs (extra bone growths) to form.

Managing pain during the day

To reduce knee pain at night, pay attention to your activities during the day, says Dr. Luga Podesta, director of sports medicine at St. Charles Orthopedics in New York.

Since arthritis pain is caused by inflammation, it’s aggravated when you overuse the joint.

“When people are walking around and not paying attention to their knees all day and then you lie down, you start feeling that inflammation from the day,” he says.

Dr. Podesta makes these recommendations:

  • If you’re walking a long distance, take breaks periodically to let your knees rest.
  • Instead of running on a treadmill, exercise on a bicycle or an elliptical to reduce strain on the joints.
  • If you experience pain with an activity, stop that activity and think about how you’re moving. It’s likely you’ll need to make a change.
  • Try water exercise. A lot of pool-based activities are helpful because they take some of the gravitational force off of your knees.
  • Avoid stairs whenever possible.
  • Lose weight. Reducing your bodyweight helps to reduce the amount of strain your body puts on its joints.

Sleeping through the night

Here are some things you can do to make your night comfortable and relaxing so you’ll be better prepared for a fresh start the next day.

  • To help find a comfortable sleep position, try placing a pillow between your knees if you sleep on your side, or under your knees if you sleep on your back. You may want to try specially designed "propping pillows."
  • If arthritis makes it difficult to get into or out of bed or to get into a comfortable position for sleeping, try satin sheets or pajamas. They're slippery and reduce friction that leads to tugging. They also make it easier to make subtle adjustments in your position, so you can drift more easily into sleep.
  • A warm, 20-minute bath before bed is not only relaxing, it may also soothe aching joints and make sleep arrive more quickly. Read a good book, light candles, or play your favorite low-key music. Make bedtime a ritual you look forward to.
  • Using a heating pad or an ice pack for 15-20 minutes before bed can ease pain before you go to sleep.
  • If arthritis pain keeps you awake, the timing of your medications may be to blame. Ask your doctor if adjusting your dosing schedule might provide more nighttime pain relief.

Next steps

There is no cure for any type of arthritis, so treatments focus on easing pain and delaying further joint damage.

People with rheumatoid arthritis and other autoimmune types of arthritis will need regular doctor’s care to treat symptoms and to prevent serious joint damage. Rheumatoid arthritis is treated with prescription medications that target the immune system to prevent it from attacking joints.

If you have mild osteoarthritis, you can generally get relief from over-the-counter pain medications and modifying your activity. As your arthritis progresses, you may need additional medical care, like physical therapy, prescription medications, or surgery.

Surgical treatments include:

  • Repairing damaged joint: This can include taking cartilage from one area of the body and adding it to the knee or smoothing or reshaping bone surfaces.
  • Joint replacement: Removing the damaged knee joint and putting a new plastic or metal joint in its place.

Since surgery involves risk and has a longer recovery time, it’s typically the last treatment option when other treatments are no longer providing adequate pain relief.

Dr. Podesta says it’s time to consider more aggressive treatments, like surgery, if your pain gets to the point where it’s so severe that it changes your ability to do everyday activities, or significantly changes your lifestyle.

Your individual treatment options will depend on how advanced your arthritis is and what area of the knee joint is most affected.