Read below about pain in the back of the knee, including causes, treatment options and remedies. Or get a personalized analysis of your pain in the back of the 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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Pain in the Back of the Knee Symptoms

As the body ages, new aches and pains begin to arise and it is often difficult to differentiate symptoms of normal aging from symptoms of injury — especially in the joints.Pain in the back of the knee is one such elusive symptom. The knee is such a large, complex and consistently utilized joint that it is susceptible to various degrees of injury.

Symptoms related to pain in the back of the knee that are more-likely associated with age-related changes include:

Symptoms associated with more serious injuries include:

  • Inability to bear weight on the knee
  • Inability to fully straighten or flex the knee
  • Fever— in addition to redness, pain, and swelling
  • Obvious deformities in the knee or leg

Being able to differentiate these symptoms associated with pain in the back of the knee is important for preventing future injury and getting appropriate care.

Pain in the Back of the Knee Causes Overview

The back of the knee is composed of various muscles, bones, ligaments, nerves and arteries. See this image to get a visual representation of the knee and all of its parts. The knee is also composed of fluid (synovial fluid) that lubricates and protects the joint. Many different processes can result in damage or injury to these components and cause pain in the back of the knee.

Inflammatory causes:

  • Arthritis: Arthritis is a general term for multiple conditions that cause painful inflammation and stiffness of the bones and joints. Arthritic processes can affect many parts of the knee and cause irritation that often leads to pain and injury.
  • Infection: The fluid in the knee can also be infected by bacteria that causes inflammation, pain, redness and swelling.
  • Fluid excess: Inflammation and injury can cause too much synovial fluid to be produced in the knee. This extra fluid can build up and form cysts, especially in the back of the knee that cause pain.

Trauma-related causes:

  • Micro: Small injuries such as tears, strains and gradual wear and tear that affect the muscles, ligaments and bones of the knee over long period of time can result in chronic knee pain both in the front and back of the knee.
  • Macro: Large traumatic injuries that affect major ligaments and fracture bones of the knee can certainly result in pain in the back of the knee symptoms.

Mechanical causes:

  • Knee pain can also be caused by problems in alignment and orientation of the knee and other parts of the body such as the hip and foot. Lack of flexibility and strength in the muscles of the area can also affect alignment. These mechanical causes may affect how you walk and change the pressure exerted on the knee resulting in pain.

A.I. Health Assistant Causes for Pain in the Back of the Knee

The list below shows results from the use of our A.I. Health Assistant by Buoy users who experienced pain in the back of the knee. This list does not constitute medical advice.

  1. 1.Baker's Cyst (Popliteal Cyst)

    A Baker's cyst, also called as Popliteal cyst, is a fluid-filled mass that causes a bulge and a feeling of tightness behind the knee. The pain can get worse when the knee is fully flexed or extended.

    Recovery with nonsurgical treatment varies

    Rarity:
    Uncommon
    Top Symptoms:
    calf pain, swollen knee, knee pain that gets worse when squatting, knee instability, dull, achy knee pain
    Symptoms that always occur with baker's cyst (popliteal cyst):
    lump on the back of the knee, constant knee lump
    Urgency:
    Primary care doctor
  2. 2.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
  3. 3.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
  4. 4.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

    Pain in the Back of the Knee Checker

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  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
  6. 6.Hamstring Strain

    A strain, commonly called a "pulled muscle," is when a muscle becomes overstretched and tears. A hamstring strain happens when one of the muscles on the back of the upper leg (thigh) is pulled.

    Most low grade strains should recover within 1 week.

    Rarity:
    Uncommon
    Top Symptoms:
    spontaneous back pain, pain in the back of the knee, hamstring tightness, sports injury, hamstring pain
    Symptoms that always occur with hamstring strain:
    hamstring pain
    Symptoms that never occur with hamstring strain:
    groin pain, hip pain, pain in the outside of the hip, difficulty moving the hip
    Urgency:
    Self-treatment
  7. 7.Rheumatoid Arthritis

    Rheumatoid arthritis (RA) is a form of arthritis that causes pain, swelling, stiffness and loss of function in your joints. It can affect any joint but is common in the wrist and fingers. RA is an autoimmune disorder, meaning that it is caused by the immune system incorrectly attacking the joints when it shouldn't.

    RA is a chronic disease which requires lifelong control.

    Rarity:
    Rare
    Top Symptoms:
    fatigue, depressed mood, joint pain, muscle aches, daytime sleepiness
    Urgency:
    Primary care doctor
  8. 8.Deep Vein Thrombosis

    Deep vein thrombosis (DVT) is a blood clot that forms in a vein deep in the body. Most deep vein clots occur in the lower leg or thigh.

    Curable with medication or surgery but may recur.

    Rarity:
    Uncommon
    Top Symptoms:
    fever, thigh pain, upper leg swelling, calf pain, butt pain
    Urgency:
    Hospital emergency room

Pain in the Back of the Knee Treatments and Relief

There are many strategies you can take to prevent knee pain and lessen your knee's susceptibility to injury.

  • Exercise correctly: Maintaining a healthy weight can reduce extra pressure and stress on the knees, but it is important to use correct form and technique during exercise as well.
  • Strengthen and Stretch: Because weak muscles and mechanical issues are a leading cause of knee pain and injury, it is important to both strengthen the major muscles of the knee such as the hamstrings and quadriceps and stretch them in order to relieve tightness. Balance and stability is key in ensuring that your knee and muscles work together effectively.
  • Apply Ice Then Heat: Putting ice on your knee will help reduce pain and relax sore or tight muscles. Limit application of ice or heat to 20 minutes at a time. You can do this every couple of hours for relief.

However, if you are experiencing chronic pain or pain more associated with serious injury, see your doctor promptly. Not addressing your pain properly can lead to increased pain, joint damage and disability.

Depending on the cause of your knee pain, your doctor may suggest the following treatments:

  • Medications: Your doctor may prescribe medications to help relieve pain in the back of the knee and swelling and treat underlying conditions like arthritis.

  • Physical Therapy: Your doctor may prescribe stretching exercises or a physical therapy/rehabilitation program to help you restore range of motion, strength and stability to your knee.

  • Injections: In some situations, your doctor may suggest injecting medications and other substances directly into the knee joint in order to reduce inflammation, lubricate the knee and promote healing.

  • Surgery: If conservative measures do not provide relief, your doctor may recommend surgical options.

FAQs About Pain in the Back of the Knee

Here are some frequently asked questions about pain in the back of the knee.

How do you know if you have a blood clot behind your knee?

Blood clots in the veins of your lower legs are called “DVTs” or “deep vein thromboses.” You may have a blood clot behind your knee if you have one-sided leg swelling, pain, warmth, and redness below the knee. Sometimes these clots can occur on both sides at once, but this is uncommon. Some blood clots in the legs, however, do not present with any symptoms. DVT needs immediate treatment to reduce the risk of embolizing to the lungs.

Why does my knee hurt when I straighten it?

Your knee is made up of bones, cartilage, muscles and tendons. When you extend your knee, your quadriceps muscles (those on the front of your thigh) tighten, and your hamstrings (those on the back) relax. Pain on knee straightening is usually indicative of damage or overuse of the quadriceps muscles, leading to tiny tears in its tendon. Pain may also occur due to any damage to the joint itself. You may get pain specifically in the back of the knee due to cyst formation following injury of the joint.

Can dehydration cause pain in the back of the knee?

In general, dehydration does not cause pain in the back of the knee. However, if you are dehydrated, you may experience cramping of your muscles. This is due to electrolyte imbalances leading to muscle irritation. This can lead to pain in the back of your leg if those muscles cramp. Most commonly, dehydration leads to exhaustion, thirst, muscle cramps, and dizziness.

Can growing pains occur in just one leg?

Usually growing pains occur bilaterally or in both legs. These pains usually occur deep in the thigh or calf in school-aged children. They generally occur at night with resolution by morning. If your child is experiencing pains in just one leg, consider bringing them for medical evaluation. One-sided leg pain can be indicative of infection, musculoskeletal injury or deformity, or other serious conditions such as a tumor.

Is it possible for adults to have "growing pains"?

No one knows for certain what causes “growing pains.” They are defined as self-limited and recurrent pains in the extremities of children with no other explanation or clear musculoskeletal causes. These usually occur during sleep and may awaken the child. Some physicians believe they occur due to fatigue, overuse, and mild orthopedic abnormalities, but the cause is still unknown. No matter what causes growing pains, we know that adults do not have them — most growing pains occur between age 2 and 12. It is possible to have similar pains, however, due to very mild injuries or overuse of muscles.

Questions Your Doctor May Ask About Pain in the Back of the Knee

  • Q.Is the knee pain affecting one or both knees?
  • Q.Do you often feel your knees buckling?
  • Q.Where is your knee pain?
  • Q.How would you explain the cause of your knee pain?

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

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Pain in the Back of the Knee Symptom Checker Statistics

  • People who have experienced pain in the back of the knee have also experienced:

    • 7% Knee Pain
    • 6% Lower Back Pain
    • 4% Knee Stiffness
  • People who have experienced pain in the back of the 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 the back of the knee were most often matched with:

    • 40% Meniscal Injury
    • 30% Baker's Cyst (Popliteal Cyst)
    • 30% Patellofemoral Pain Syndrome
  • 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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