man massaging painful knee

Understanding Knee Pain: Causes, Symptoms & Remedies

We ask a lot from our knees. They bear most of our body weight, and we expect them to be both flexible (while walking and bending) and rigid (when standing). When our knees start to hurt, it can really disrupt our quality of life. Knee pain is a common complaint that affects people of all ages and activity levels.

The knee joint is the most complicated joint in the human body. Because of its anatomical structure—it consists of three bones and two joints—it is extremely prone not only to injury, but also to wear and tear. Some of the most common knee problems we see include sprained and torn ligaments, meniscal tears, tendinitis, overuse injuries, and osteoarthritis.

The bones in the knee joint—the femur, tibia and patella—are capped by articular cartilage, which is a smooth, slippery, nerve-free surface that protects the bones and allows the joint to glide smoothly. With arthritis, the cartilage flattens out and looses elasticity, and degenerative damage to the cartilage will eventually expose the bone located underneath. The resulting inflammation causes pain, stiffness and swelling.

Common Causes of Knee Pain


Knee injuries can cause trauma to your knee joint, as well as to the bones, cartilage and ligaments that form the joint itself. Common knee injuries include:

  • ACL injury. The anterior cruciate ligament is a sinewy band of tissue that runs diagonally in the middle of the knee, preventing your tibia from sliding out in front of the femur. It provides rotational stability to the knee. When the ACL is partially or completely torn, patients will experience pain and swelling, and the knee will feel unstable.
  • Knee sprain. A knee sprain refers to torn or overstretched ligaments. The knee has four main ligaments—anterior cruciate (ACL), posterior cruciate (PCL), medial collateral (MCL), and lateral collateral (LCL)—and a knee sprain may involve one or more of them. It typically occurs as a sports injury, or as the result of significant trauma to the joint. Symptoms include stiffness, pain, swelling or bruising, and instability.
  • Dislocation. A knee dislocation occurs when the bones that form the knee—the femur (thigh bone), tibia (shin bone) and patella (kneecap)—become disconnected. It is usually the result of trauma, either from a fall or a sports injury, and can cause damage to adjacent ligaments, blood vessels and nerves. Symptoms include severe swelling, pain and instability.
  • Fractures. The bones of the knee, including the kneecap (patella), can be broken when subjected to blunt force. Common causes of fractures include auto accidents, falls, and sports injuries. Osteoporosis can also play a role. Symptoms include noticeable and unusual bumps, bends or twists in the knee, severe pain and swelling, and difficulty bearing weight on the limb.
  • Torn meniscus. The meniscus is a c-shaped piece of robbery cartilage that acts as a shock absorber between your shin and thigh bones. Each knee has two menisci, which help cushion and stabilize the joint. Athletes who play contact sports are especially susceptible to meniscal tears. Symptoms of a torn meniscus include knee pain, swelling, popping in the knee joint, and a feeling that your knee is giving way.
  • Bursitis. Your knee joint is surrounded by fluid-filled sacs (bursae) that reduce friction and cushion the pressure points between your bones and tendons. When these sacs become inflamed, it can cause pain and swelling, and limit your mobility.
  • Patellar tendinitis. The patellar tendon runs from the kneecap (patella) to the shinbone. Inflammation of this tendon, called patellar tendinitis, weakens the tendon and may cause small tears. This injury is common in runners, skiers and cyclists, and is sometimes called “jumpers knee.” Symptoms include pain, usually between your kneecap and tibia, that worsens over time.

Mechanical problems

Some examples of mechanical problems that can cause knee pain include:

  • Loose body. This is a general term for bits of bone or articular cartilage that break off in the knee joint as a result of injury or degeneration. These loose bodies float around in the knee fluid (synovium), causing pain, catching, swelling, or locking depending on where they migrate within the joint.
  • Dislocated knee cap. This occurs when the triangular bone (patella) that covers the front of your knee slips out of place.
  • Gait issues. If you have hip or foot pain, it can cause you to alter the way you walk in order to minimize the pain. This altered gait can place more stress on your knee joint.
  • Iliotibial band syndrome. The illiotibial band is a tough band of tissue that extends from outside your hip to the outside of your knee. Iliotibial band syndrome, also known as IT band syndrome, is an overuse injury that occurs when this connective tissue becomes so tight that it rubs against the outside portion of your femur. The primary symptom is pain between the hip and knees that worsens with activity. Distance runners and cyclists are particularly susceptible to this problem.
  • Baker’s Cyst. Also known as a popliteal or synovial cyst, a Baker’s cyst is a soft, fluid-filled lump that forms at the back of your knee. It forms as the result of joint damage that causes swelling in the knee. Symptoms include a noticeable lump behind your knee. It’s not necessarily painful, but when the cyst swells, it can increase your pain and limit how much you can move your knee.


There are more than 100 types of arthritis and each type of arthritis has different treatments. Knee osteoarthritis, also known as degenerative arthritis, is caused by wear and tear on the cartilage and bones in the knee joint that develops over time, although traumatic osteoarthritis can also develop after an injury to the joint.

In general, the pain associated with arthritis develops gradually, although sudden onset is also possible. The pain of arthritis may come from different sources. These may include inflammation of the synovial membrane (tissue that lines the joints), the tendons, or the ligaments; torn cartilage or cartilage defects; muscle strain; and fatigue.  A combination of these factors contributes to the intensity of the pain.

In knees, the joint may become stiff and swollen, making it difficult to bend or straighten the knee. Pain and swelling are worse in the morning or after a period of inactivity. Pain may also increase after activities such as walking, stair climbing or kneeling. The pain may often cause a feeling of weakness in the knee, resulting in a “locking” or “buckling” sensation. Many people report that changes in the weather also affect the degree of pain from arthritis.

When the arthritis is non-inflammatory, the pain is worse with use and usually worse at the end of the day. When the pain is due to inflammation, frequently pain and stiffness are greatest in the morning or after a long period of rest. Symptoms are relieved by heat and gentle exercise. Of course, the most important symptom of arthritis is decreased function, sometimes caused by pain, and sometimes because the joint does not move properly.

What treatments are available for managing knee pain?

Treatments for knee pain can be divided into several categories, including:    

  • Medication:  Many drugs, both prescriptions and over-the-counter medications, are used to treat knee pain, especially when the pain is caused by osteoarthritis.  Common medications are aspirin-free pain relievers, anti-inflammatories, corticosteroids, disease modifiers, and sleep medications.
  • Injections: Corticosteroid injections can help relieve pain and inflammation in your knee joint. During the procedure, which can be done in your doctor’s office, a corticosteroid medication and local anesthetic are injected directly into the knee joint. Hyaluronic acid injections are helpful for mild to moderate arthritis; they increase the viscosity of joint fluid and the elasticity of the joint cartilage, and are also thought to have a mild pain-relieving effect. 
  • Exercise and Physical Therapy:  The golden rule of joint health is that the more you move, the less stiffness you’ll have. Regular exercise is essential to keep the body moving and flexible.  Not only does it help lessen pain, increase mobility, and reduce fatigue, but it also helps you look and feel better. The best exercise choices are activities that don’t pound your joints, such as walking, bicycling, swimming and strength training.
  • R.I.C.E.:  R.I.C.E. is an acronym for rest, ice, compression, and elevation, a process that can provide short-term relief from pain and stiffness. Ice is used when an injury is acute, and accompanied by pain, inflammation, and swelling.  Alternatively, heat therapy is used to alleviate muscle pain and stiffness.
  • Ease the load on your joint: Avoiding excess stress on your joints can help protect them. When lifting and carrying items let your bigger muscles and joints support the weight.  The second method is walking with assistive devices.  Lastly, weight control helps ease pain by reducing stress on your joints.     
  • Surgical intervention:  When traumatic injury to the knee joint occurs, or when conservative measures for treating knee pain are exhausted, surgery may be warranted. Surgical treatments may include cartilage restoration, meniscus repair, tendon repair and reconstruction, minimally invasive surgery (knee arthroscopy), partial knee replacement, and/or total knee replacement  

What’s a good rule of thumb for when to see a doctor about your knee pain?

If your knee is swollen, feeling unstable, or the pain and discomfort is affecting your function in some way, it’s time to see the orthopedic experts at OrthoEdge.