What Is Knee Pain? Symptoms, Causes, Treatment, and Medications
Knee pain is discomfort in or around the knee joint caused by injury, mechanical wear, or inflammatory disease. Osteoarthritis is the leading cause in adults over 50. Treatment ranges from physical therapy and over-the-counter pain relievers to prescription medications, injections, and in advanced cases, surgery.
Key Highlights
- Knee pain can stem from injuries, mechanical problems, or arthritis, with osteoarthritis being the most common cause in adults over 50.
- Common symptoms include pain during or after movement, stiffness, swelling, reduced range of motion, and a grinding or popping sensation.
- First-line medications include acetaminophen, oral NSAIDs such as ibuprofen and naproxen, and topical diclofenac gel (Voltaren Arthritis Pain).
- Corticosteroid and hyaluronic acid injections, and the SNRI duloxetine (Cymbalta, FDA approved for chronic musculoskeletal pain), are options when first-line care is not enough.
- Physical therapy, weight management, and low-impact exercise are cornerstones of long-term knee pain management.
- PriceMyMeds discount coupons can help reduce the cost of knee pain prescriptions at participating pharmacies, with no insurance required.
What Is Knee Pain?
Knee pain is discomfort felt in, around, or behind the knee joint. It is a symptom rather than a single disease, and it can come from the joint itself or from the surrounding soft tissues, including ligaments, tendons, and the fluid-filled bursae. Per Mayo Clinic, knee pain may result from an injury such as a ruptured ligament or torn cartilage, from mechanical problems, or from types of arthritis, including osteoarthritis, rheumatoid arthritis, and gout.
The severity and location of knee pain vary widely depending on the cause. Many minor cases respond well to self-care, physical therapy, and knee braces, while others need medication, injections, or surgery.
Key Facts:
- Generic names: acetaminophen, ibuprofen, naproxen, diclofenac, duloxetine, triamcinolone (injectable), hyaluronic acid (injectable)
- Drug classes: analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs), SNRI, corticosteroids, viscosupplements
- FDA approvals: topical diclofenac 1% gel approved over the counter in 2020; duloxetine approved for chronic musculoskeletal pain in 2010
- Typical cost: many oral generics run about $4-$40; topical and prescription options and injections cost more
- Common uses: osteoarthritis of the knee, injury-related pain, inflammatory joint pain
Knee Pain vs. Knee Osteoarthritis: Understanding the Difference
Knee pain is a broad symptom, while knee osteoarthritis is one specific cause of it. Osteoarthritis is a wear-and-tear condition in which the cartilage that cushions the ends of the bones gradually breaks down, leading to pain, stiffness, and reduced motion. Not all knee pain is arthritis - it can also come from ligament tears, meniscus injuries, tendinitis, bursitis, or gout. Only a healthcare provider can determine the underlying cause through examination and imaging.
What You Need to Know
Understanding Knee Pain: Causes, Symptoms, Diagnosis, Treatment, and Prevention
1.What Are the Causes of Knee Pain?
Knee pain can result from acute injuries, mechanical problems, and various types of arthritis, as well as overuse.
Injuries
- ACL injury (tearing of the anterior cruciate ligament)
- Torn meniscus (torn cartilage)
- Knee bursitis (inflammation of fluid-filled sacs)
- Patellar tendinitis (inflammation of the tendons)
- Fractures of the kneecap or other bones
Mechanical Problems
- Loose body (a piece of bone or cartilage floating in the joint space)
- Iliotibial band syndrome
- Dislocated kneecap
- Hip or foot pain that changes your gait and stresses the knee
Types of Arthritis
- Osteoarthritis - the most common type, a wear-and-tear degeneration of cartilage
- Rheumatoid arthritis - an autoimmune disease that can affect the knees
- Gout - buildup of uric acid crystals in the joint
- Septic arthritis - joint infection causing pain, swelling, and fever
Risk factors that raise the chance of knee problems include excess weight, lack of muscle flexibility or strength, certain sports or occupations, and previous knee injury.
2.What Are the Symptoms of Knee Pain?
The location and severity of knee pain vary depending on the cause. Signs and symptoms that sometimes accompany knee pain include the following.
Common knee pain symptoms:
- Swelling and stiffness
- Redness and warmth to the touch
- Weakness or instability
- Popping or crunching noises
- Inability to fully straighten the knee
- Pain during or after movement
In osteoarthritis specifically, pain is often worse during or after activity, stiffness is most noticeable in the morning or after inactivity, and a grating or crackling sensation may occur with movement.
How Long Does Knee Pain Last?
The duration depends on the cause:
- Minor strains and overuse: days to a few weeks with rest and self-care
- Bursitis or tendinitis: several weeks, sometimes recurring
- Ligament or meniscus tears: weeks to months, and may need surgery
- Osteoarthritis: chronic and progressive; managed long term rather than cured
Seek prompt care if the knee is severely swollen, cannot bear weight, or the pain follows a significant injury.
3.How Is Knee Pain Diagnosed?
Doctors diagnose the cause of knee pain using your history, a physical exam, and imaging or lab tests when needed.
A healthcare provider may ask:
- When and how did the pain start?
- Was there a specific injury or fall?
- Does the pain worsen with activity or at rest?
- Is there swelling, locking, or a feeling of instability?
- Do you have a history of arthritis or gout?
During the exam, the provider inspects the knee for swelling, tenderness, warmth, and bruising, checks how far you can move it, and pushes or pulls the joint to test the ligaments and other structures.
Diagnostic tests may include:
- X-ray - to detect bone fractures and degenerative joint disease
- CT scan - to diagnose bone problems and subtle fractures
- Ultrasound - to view soft-tissue structures
- MRI - to reveal injuries to ligaments, tendons, cartilage, and muscles
- Joint aspiration (arthrocentesis) and blood tests - to check for infection, gout, or inflammatory arthritis
4.How Is Knee Pain Treated?
Treatment depends on the cause. Many cases improve with a combination of self-care, medication, and physical therapy.
1. Medications
- Acetaminophen for mild to moderate pain
- Oral NSAIDs such as ibuprofen and naproxen to reduce pain and inflammation
- Topical NSAIDs such as diclofenac 1% gel (Voltaren Arthritis Pain) applied directly to the knee
- Duloxetine (Cymbalta), an SNRI FDA approved for chronic musculoskeletal pain, for persistent osteoarthritis pain
Physical Therapy and Exercise
Strengthening the muscles around the knee makes the joint more stable. Low-impact exercise, stretching, and, when appropriate, arch supports or braces help relieve pain and improve function.
3. Injections
- Corticosteroid injections may relieve pain and inflammation for weeks to months
- Hyaluronic acid (viscosupplementation) injections may cushion and lubricate the joint in osteoarthritis
- Platelet-rich plasma (PRP) is used in some cases
4. Surgery
When conservative treatment fails, options include arthroscopic surgery to repair or remove damaged tissue, partial knee replacement, or total knee replacement. There is currently no medication that reverses osteoarthritis.
5.What Are the Complications of Knee Pain?
Some causes of knee pain, if left untreated, can lead to increasing pain, joint damage, and disability. Possible complications include:
- Chronic pain that limits daily activities and mobility
- Progressive cartilage loss and worsening osteoarthritis
- Joint instability and repeated giving way, raising the risk of falls
- Muscle weakness and wasting from reduced use of the leg
- Deformity of the joint in advanced arthritis
- Spread of infection in the rare case of septic arthritis
Long-term use of NSAIDs can also cause side effects such as stomach ulcers, gastrointestinal bleeding, kidney problems, and increased cardiovascular risk, so these medications should be used at the lowest effective dose and under medical guidance.
6.How Can Knee Pain Be Prevented?
While not all knee pain is preventable, these steps lower the risk and slow the progression of osteoarthritis:
- Maintain a healthy weight to reduce stress on the knee joints
- Stay active with low-impact exercise such as swimming, cycling, or walking
- Strengthen and stretch the muscles that support the knee, especially the quadriceps and hamstrings
- Use proper form and technique during sports and exercise
- Wear supportive shoes and replace worn athletic footwear
- Warm up before activity and increase intensity gradually
- Address minor injuries promptly before they worsen
7.When to See a Doctor for Knee Pain
Contact your doctor if your knee pain does not improve with self-care or if it interferes with daily activities.
See a healthcare provider if you:
- Cannot bear weight on the knee or feel that it is unstable
- Have marked knee swelling
- Are unable to fully extend or flex the knee
- See an obvious deformity in your leg or knee
- Have a fever along with redness, pain, and swelling in the knee
- Have severe knee pain that follows an injury
Seek immediate care for a knee injury with a popping sound, a knee that cannot support your weight, or intense pain, as these may signal a serious ligament or bone injury.
8.OTC vs. Prescription Knee Pain Medications: When Do You Need a Prescription?
Over-the-counter (OTC) options work well for mild to moderate knee pain. These include:
- Acetaminophen (Tylenol) for pain relief
- Oral NSAIDs such as ibuprofen (Advil, Motrin) and naproxen (Aleve)
- Topical diclofenac 1% gel (Voltaren Arthritis Pain), which the FDA approved for OTC use in 2020
- Topical menthol, capsaicin, or lidocaine rubs
You should see a doctor for prescription treatment if:
- Your pain is moderate to severe or persists despite OTC care
- You need higher-strength NSAIDs or prescription diclofenac
- You may benefit from duloxetine (Cymbalta) for chronic osteoarthritis pain
- A corticosteroid or hyaluronic acid injection is being considered
A provider can confirm the cause of your knee pain and choose the safest, most effective option based on your health history and other medications.
Save on Your Medications
Knee pain medications can vary significantly in price depending on the drug, the pharmacy, and whether you use a generic or brand-name version. Many oral generics, such as ibuprofen, naproxen, and acetaminophen, are inexpensive, while prescription duloxetine and topical or injectable products can cost more. With PriceMyMeds discount coupons, patients may be able to reduce the cost of knee pain prescriptions at participating pharmacies across the United States.
Simply search for your medication on PriceMyMeds, compare prices at pharmacies near you, and present your free coupon at the pharmacy counter to save. No insurance required.
Comparing medication prices and using discount coupons may help lower out-of-pocket costs for knee pain treatment.
The Bottom Line
Knee pain is a common symptom that can arise from injuries, mechanical problems, or arthritis, with osteoarthritis being the leading cause in older adults. Most cases respond to a combination of self-care, physical therapy, weight management, and medication.
Treatment options range from over-the-counter acetaminophen and NSAIDs, including topical diclofenac gel, to prescription duloxetine and corticosteroid or hyaluronic acid injections, with surgery reserved for advanced cases. Knowing when to treat knee pain at home versus when to see a doctor helps you protect the joint and stay active.
If you are prescribed medication for knee pain, use PriceMyMeds to compare prices at nearby pharmacies and potentially save on your prescription costs. No insurance or signup required.