If your knee pain started suddenly, or soon after a particular movement you made, then you may already have a good idea of how it happened — even if you don’t know exactly what the problem is.

Maybe you were playing basketball or hiking, or maybe you fell and hit your knee on the ground. The pain may have been a sharp, stabbing pain or it may have been an ache that worsened in the hours or days that followed.

But what if your knee pain occurred more gradually, with no obvious cause? It might have started out as a minor nuisance that didn’t really grab your full attention for months, or longer.

While injuries are among the most common knee pain causes, there are other reasons your knee could be hurting. An underlying condition, such as arthritis, could be the culprit.

Although we’ll provide information about what causes knee pain in this blog post, it’s best to have your knee examined by a medical professional — especially if the pain persists, grows worse or is accompanied by swelling.

Knee pain is a common ailment. It’s also one that can become a chronic issue if the cause isn’t properly treated.

Common Causes of Knee Pain

As we noted earlier, the causes of knee pain and swelling include injuries and other medical conditions. Here, we’ll cover six of the most common knee pain causes. If you’re wondering what can cause knee pain without injury, you’ll want to focus on the first two sections.

• Osteoarthritis. The most common joint disorder, osteoarthritis typically affects people who are middle-age or older. Wear and tear on the joint causes the cartilage between the bones to break down. When the bones are no longer cushioned, they rub against each other. This can cause pain, stiffness and swelling. Previous joint injuries, certain occupations and some sports can increase the risk of developing osteoarthritis.
• Rheumatoid arthritis. This type of arthritis is an autoimmune disease that can occur at any age. Along with the joints, it can also affect organs such as the lungs and heart. Usually, it affects the same joints on both sides of the body. Rheumatoid arthritis can cause inflammation in the joint and damage the cartilage.
• Ligament injuries. Ligaments are elastic bands of tissue that help to stabilize a joint. In the knee, they connect the femur, which is the thigh bone, and the tibia, or shin bone. Of the four main ligaments in the knee, the anterior cruciate ligament (ACL) is one of the most commonly injured. It stretches across the center of the knee in front, controlling the rotation and the forward movement of the tibia. A sudden twisting of the knee can tear the ACL.
• Tendon injuries. Tendons attach muscle to bone. Overuse or injury of a joint can cause the tendons to become inflamed (tendonitis). In the knee, the patellar tendon runs from the kneecap, or patella, to the shin bone, or tibia. When this tendon becomes inflamed, it’s sometimes referred to as jumper’s knee. Why? Because this type of knee injury is common in sports like basketball that involve jumping (see our article on how to treat knee pain from basketball).
• Cartilage injuries. Cartilage is the soft tissue between the bones in a joint. It cushions the bones and prevents them from rubbing against each other. Each knee has two pads of cartilage, called menisci, that also help to stabilize the knee. Tears in a meniscus can occur suddenly as the result of trauma. They can also result from wear and tear.
• Dislocated kneecap. The patella, or kneecap, is a round bone on the front of the knee that is attached to the thigh and shin bone by tendons. A groove at the end of the thigh bone holds the patella in place as it slides up and down when the knee is bent and straightened. A knee injury can cause the patella to be dislocated, or pushed sideways out of the groove.

When to See a Knee Specialist

In some cases, it’s clear that a visit to a specialist is what you should do. If, in addition to being painful, your knee is very noticeably swollen, is warm and/or tender to the touch, looks deformed or has a limited range of motion that doesn’t improve, then it’s time to make an appointment. These could all be signs of a debilitating injury.

In other cases, it might not be so obvious. Here’s a good rule of thumb to follow for knee pain or other types of joint pain: If the pain is causing lifestyle changes, such as restricting your activities or interfering with your sleep, then you should seek the advice of a specialist.

Treatment for your knee pain could range from conservative steps, such as rest, icing, ibuprofen and possibly a brace to keep your knee stable while it heals, to a surgical procedure to repair the damage that’s causing the pain.

A specialist will examine your knee, request imaging if necessary to diagnose the issue, and advise you on the right course of treatment based on your age, severity of the injury or disease and other factors unique to your case.

Knee pain causes vary. The most important takeaway is not to ignore the pain. Doing so could lead to a more severe injury or a chronic problem, and either of those could require advanced treatment and a lengthier recovery time.

If you’re experiencing prolonged and unexplained pain in your knee, don’t hesitate to give your knee specialists at The Joint Replacement Center of Scottsdale a call today.