Read below about pain in one knee, including causes and common questions. Or get a personalized analysis of your pain in one knee from our A.I. health assistant. At Buoy, we build tools that help you know what’s wrong right now and how to get the right care.

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10 Potential Pain in One Knee Causes

Disclaimer: The article does not replace an evaluation by a physician. Information on this page is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes.

  1. 1.Non - Specific Knee Pain

    Knee pain is a common symptom in people of all ages. It may start suddenly often as a result of injury or excessive exercise. Knee pain may also began as a mild discomfort & worsen over time.

    1-2 days

    Rarity:
    Common
    Top Symptoms:
    pain in one knee, spontaneous knee pain, knee pain from overuse
    Symptoms that always occur with non-specific knee pain:
    pain in one knee
    Symptoms that never occur with non-specific knee pain:
    severe knee pain, knee pain from an injury, difficulty walking
    Urgency:
    Self-treatment
  2. 2.Patellofemoral Pain Syndrome

    The kneecap (patella) is located directly in front of the thigh bone (femur), and should normally glide freely up and down. In this condition, called patellofemoral pain syndrome, the kneecap may rub against the thigh bone instead of gliding smoothly, causing damage and pain.

    Most people get better within weeks to months of physical therapy.

    Rarity:
    Common
    Top Symptoms:
    knee pain, pain in one knee, knee pain that gets worse when going up stairs, dull, achy knee pain, knee pain that gets worse when squatting
    Symptoms that always occur with patellofemoral pain syndrome:
    knee pain
    Urgency:
    Primary care doctor
  3. 3.Knee Bursitis (Pes Anserine Bursitis)

    Pes anserine bursitis is an inflammatory condition of the knee.

    Days to weeks (up to 8 weeks)

    Rarity:
    Common
    Top Symptoms:
    pain in one knee, knee pain that gets worse when going up stairs, spontaneous knee pain, knee pain that gets worse when going down stairs, knee pain that gets worse when standing up
    Symptoms that always occur with knee bursitis (pes anserine bursitis):
    pain in one knee
    Urgency:
    Self-treatment
  4. 4.Meniscal Injury

    A torn meniscus is one of the most common knee injuries. Any activity that causes forceful twisting of the knee, especially when putting the pressure of one's full weight on it, can lead to a torn meniscus.

    6 to 8 weeks

    Rarity:
    Common
    Top Symptoms:
    pain in one knee, knee stiffness, knee instability, pain in the inside of the knee, swollen knee
    Urgency:
    Primary care doctor
  5. 5.Iliotibial (It) Band Syndrome ('Runner's Knee')

    Iliotibial band (ITB) syndrome is the lateral knee pain that results from overuse that occurs after repetitive motion. It is the most common cause of lateral knee pain in runners and cyclists.

    Within 6 to 8 weeks with conservative nonsurgical treatment

    Rarity:
    Common
    Top Symptoms:
    knee pain, pain in one knee, dull, achy knee pain, knee pain that gets worse when going down stairs, sharp knee pain
    Symptoms that always occur with iliotibial (it) band syndrome ('runner's knee'):
    knee pain
    Urgency:
    Primary care doctor

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  6. 6.Hip Fracture

    A hip fracture is a break in the upper quarter of the femur (thigh) bone. The extent of the break depends on the forces that are involved, which determines the type of surgery used for treatment.

    Full recovery can take from 2-3 months to a year

    Rarity:
    Common
    Top Symptoms:
    pain in one knee, constant hip pain, groin pain, severe hip pain, limping
    Symptoms that always occur with hip fracture:
    hip pain from an injury, constant hip pain
    Urgency:
    Emergency medical service
  7. 7.Infrapatellar Bursitis

    Bursae are small fluid-filled sacks located around the body in strategic locations to provide a cushion and help reduce friction. There is a pair of bursae below each kneecap (patella). Infrapatellar bursitis is a condition where these bursae are inflamed. It is a common cause of knee pain in people whose work involves frequent kneeling on hard surfaces.

    Condition goes away on its own in a few weeks.

    Rarity:
    Uncommon
    Top Symptoms:
    pain in one knee, spontaneous knee pain, dull, achy knee pain, knee pain that gets worse when going up stairs, knee pain that gets worse when squatting
    Urgency:
    Self-treatment
  8. 8.Knee (Mcl) Sprain

    The medical collateral ligament (MCL) links the thigh bone and the shin bone on the inner side of the knee joint. An MCL sprain is any damage done to this ligament (usually through twisting/force during sports).

    From 2 weeks (first-degree sprains) to between 6 to 8 weeks (second-degree sprains)

    Rarity:
    Uncommon
    Top Symptoms:
    pain in one knee, knee pain from an injury, knee injury, pain in the inside of the knee, sports injury
    Symptoms that always occur with knee (mcl) sprain:
    pain in one knee, knee pain from an injury
    Symptoms that never occur with knee (mcl) sprain:
    mild knee pain
    Urgency:
    Primary care doctor
  9. 9.Jumper's Knee (Patellar Tendonitis)

    Patellar tendonitis (Jumper's knee) is the inflammation of the patellar tendon, which attaches the knee cap to the shin bone (tibia). This condition is caused by frequently from sports and jumping.

    1 month with rest

    Rarity:
    Rare
    Top Symptoms:
    pain in one knee, spontaneous knee pain, knee pain that gets worse when going up stairs, knee stiffness, knee pain that gets worse when squatting
    Urgency:
    Primary care doctor
  10. 10.Repeated Kneecap Dislocation (Patellar Subluxation)

    Recurrent patellar subluxation is the continued instability of the kneecap, which causes anterior knee pain and usually occurs laterally. It occurs unpredictably with varying durations.

    Recovery timeline is dependent on treatment type.

    Rarity:
    Uncommon
    Top Symptoms:
    pain in one knee, dull, achy knee pain, pain in the front of the knee, pain in the inside of the knee, swollen knee
    Symptoms that always occur with repeated kneecap dislocation (patellar subluxation):
    kneecap dislocation
    Urgency:
    Primary care doctor

Questions Your Doctor May Ask About Pain in One Knee

  • Q.How would you explain the cause of your knee pain?
  • Q.Which of the following describes your physical fitness:
  • Q.Is your knee pain:
  • Q.Where is your knee pain?

If you've answered yes to one or more of these questions, try our pain in one knee symptom checker to find out more.

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Pain in One Knee Symptom Checker Statistics

  • People who have experienced pain in one knee have also experienced:

    • 8% Pain in One Hip
    • 7% Lower Back Pain
  • People who have experienced pain in one knee had symptoms persist for:

    • 40% Over a Month
    • 20% Less Than a Day
    • 19% Less Than a Week
  • People who have experienced pain in one knee were most often matched with:

    • 54% Patellofemoral Pain Syndrome
    • 11% Knee Bursitis (Pes Anserine Bursitis)
  • Source: Aggregated and anonymized results from visits to the Buoy AI health assistant (check it out by clicking on “Take Quiz”).

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