Common Knee Pain Symptoms, Causes, and Treatments

Knee pain is an extremely common problem, and often a very treatable problem. Understanding what is causing your knee pain may be a simple task. A skilled physician can use clues to determine the cause. Some of these clues have to do with you—how old are you and what types of activities do you do—and some with your symptoms—has your knee pain been ongoing or was there a recent injury?

Determining the cause of knee pain relies on a proper examination of the knee joint by a medical professional. But here are some common knee pain symptoms and a few possibilities about what they may indicate.

Finding the Cause

Location: Where on the knee the patient feels pain can offer some clues about what type of injury or condition is causing the pain. For instance, pain on the inside or medial side of the knee (the side closest to the other knee) can be caused by medial meniscus tears, MCL injuries, and arthritis.

Pain on the outside of the knee, or lateral side, is commonly caused by lateral meniscus tears, LCL injuries, IT band tendonitis, and arthritis. Pain in the back of the knee can be due to the collection of fluid, called a Baker's Cyst. Pain over the front of the knee is most commonly related to the kneecap, and can be caused by several different problems.
Timing: Just as the location of knee pain may indicate what's causing the problem, the time of day the patient experiences the pain can also offer insight. Pain while walking down steps is very commonly associated with kneecap problems, such as chondromalacia. Knee pain after first waking in the morning that quickly resolves with gentle activity is typical of early arthritis.

Swelling: Swelling of the knee is common with several different knee problems. When there is an effusion immediately after a knee injury, a possible cause is a severe injury to an internal joint structure, like the anterior cruciate ligament or a fracture of the top of the shin bone.

When swelling develops gradually over hours to days after an injury, it is likely to be something less severe, like a tear of the meniscus or a ligament sprain. Swelling that occurs without a present known injury can be due to osteoarthritis (common), gout (less common), inflammatory arthritis, or a joint infection (uncommon).

Range of Motion: Mobility of the knee can be affected by a number of common conditions. If mobility is chronically limited, often the cause is arthritis. When the surface of the joint becomes irregular as a result of arthritis, the mobility of the joint may become limited. If the mobility is limited after an acute injury, there is likely swelling limiting the motion, or a torn structure that is limiting the mobility.

The stability of the knee is provided by the ligaments that connect the shin bone (tibia) to the thigh bone (femur). When the ligaments are stretched or torn, the knee may feel as though it is giving way beneath the patient. A sensation that the knee may give out from beneath you is a common symptom of ligament injury.
Noises: Popping and snapping within the knee is common, and often not a symptom of any particular problem. When the pops are painless, there is usually no problem, but painful pops and snaps should be evaluated by your doctor. A pop is often heard or felt during an injury when a ligament, such as the ACL, is torn. Grinding or crunching are common symptoms of cartilage problems. If the cartilage is damaged—a condition called chondromalacia—a crunching sensation is often felt by placing the hand over the kneecap and bending the knee. A similar grinding sensation may be felt with knee arthritis.

Locking: Locking is a symptom that occurs when a patient cannot bend or straighten their knee. The locking can either be due to something physically blocking motion of the knee, or by pain preventing normal knee motion. One way to determine if there is something physically blocking knee motion is to have a health care professional inject the knee with a numbing medication. After the medication has taken effect, you can attempt to bend the knee to determine if the pain was blocking the motion or if there is a structure, such as a torn meniscus, that is blocking normal motion.

Common Causes

Knee pain is an extremely common complaint, and there are many causes.

It is important to make an accurate diagnosis of the cause of your symptoms so that appropriate treatment can be directed at the cause. If you have knee pain, some common causes include:

Knee Arthritis: Arthritis is among the most common causes of knee pain, and there are many treatments available.
Ligament Injuries: Ligament injuries commonly occur during athletic activities and can cause discomfort and instability.
Cartilage Injuries | Meniscal Tear: Cartilage tears are seen in young and old patients alike, and are also an extremely common cause of knee pain.
Patellar Tendonitis: Tendonitis around the joint is most commonly of the patellar tendon, the large tendon over the front of the knee.
Chondromalacia Patella: Chondromalacia causes knee pain under the kneecap and is due to softening of the cartilage. It is most common in younger patients (15-35 years old).
Dislocating Kneecap: A dislocating kneecap causes acute symptoms during the dislocation, but can also lead to chronic knee pain.
Baker's Cyst: A Baker's cyst is swelling in the back of the joint, and is usually a sign of another underlying problem such as a meniscus tear.
Bursitis: The most common bursa affected around the joint is just above the kneecap. This is most common in people who kneel for work, such as gardeners or carpet layers.
Plica Syndrome: Plica syndrome is an uncommon cause of knee pain, and can be difficult to diagnose. The diagnosis is usually made at the time of arthroscopy.
Osgood-Schlatter Disease: Osgood-Schlatter disease is a condition seen in adolescents and is due to irritation of the growth plate just at the front of the joint.
Osteochondritis Dissecans: Osteochondritis dissecans (OCD) is another condition seen in adolescents due to the growth of the bone around the joint.
Gout: Gout is an uncommon cause of knee pain. However, in patients who have a diagnosis of gout, it must be considered as a cause for new onset knee pain.

When to See a Doctor

If you are unsure of the cause of your symptoms, or if you do not know the specific treatment recommendations for your condition, you should seek medical attention. Treatment of knee pain must be directed at the specific cause of your problem. Some signs that you should be seen by a doctor include:

Inability to walk comfortably on the affected side
Injury that causes deformity around the joint
Knee pain that occurs at night or while resting
Knee pain that persists beyond a few days
Locking (inability to bend) the knee
Swelling of the joint or the calf area
Signs of an infection, including fever, redness, warmth
Any other unusual symptoms

Treatments

Some common treatments for knee pain are listed here. Not all of these treatments are appropriate for every condition, but they may be helpful in your situation.

Rest: The first treatment for most common conditions that cause knee pain is to rest the joint, and allow the acute inflammation to subside. Often this is the only step needed to relieve knee pain. If the symptoms are severe, crutches may be helpful as well.
Ice and Heat Application: Ice packs and heat pads are among the most commonly used treatments for knee pain. So which one is the right one to use, ice or heat? And how long should the ice or heat treatments last?
Stretching: Stretching the muscles and tendons that surround the joint can help with some causes of knee pain.
Physical Therapy: Physical therapy is an important aspect of treatment of almost all orthopedic conditions. Physical therapists use different techniques to increase strength, regain mobility, and help return patients to their pre-injury level of activity.
Anti-Inflammatory Medication: Nonsteroidal anti-inflammatory medications, commonly referred to as NSAIDs, are some of the most commonly prescribed medications, especially for patients with knee pain caused by problems such as arthritis, bursitis, and tendonitis.
Cortisone injections: Cortisone is a powerful medication that treats inflammation, and inflammation is a common problem in patients with knee pain. Discuss with your doctor the possible benefits of a cortisone injection for your condition.

A Word From Verywell

Treatment of knee pain depends entirely on the cause of the problem. Therefore, it is of utmost importance that you understand the cause of your symptoms before embarking on a treatment program. If you are unsure of your diagnosis, or the severity of your condition, you should seek medical advice before beginning any treatment plan.