There are many causes of pain in the back of the knee. Some are common and less serious while others require more immediate medical attention.
The knee is a complex joint, and it takes a lot of impact from even simple everyday activities. Knee damage can often be reduced or prevented by avoiding impact and strain on the joint.
Treatment for pain in the back of the knee will vary greatly depending on the cause.
Fast facts on pain in the back of the knee:
There are many possible causes for this kind of pain.
Early treatment for knee pain often involves preventing the injury from getting worse.
- In some cases, the pain may be caused by fatigue, or not stretching before exercise.
What are the causes?
It may be important to work closely with a doctor to diagnose pain in the back of the knee, as some causes require long-term treatment to heal completely.
Possible causes for pain in the back of the knee include:
Cramps are when muscles become too tight. This tightness may be because the muscle is doing too much work without being stretched. If it is stretched and still cramps, the muscle may simply be overused.
Overuse syndrome can affect different areas of the knee. A person might feel a cramp in the thigh or calf near the knee.
The sensation resembles a sudden, painful spasm of the muscle. The pain may last seconds or minutes and can range from uncomfortable to severe.
Other possible reasons for leg cramp include:
- infection such as tetanus
- liver disease
- excess toxins in the blood
- nerve problems
Women who are pregnant may also experience leg cramps as a normal side effect of pregnancy.
Some people who often experience leg cramps may find relief through regularly stretching their calves. Also, they can try shortening their stride to put less strain on the knee and surrounding muscles.
A Baker's cyst is a pocket of fluid that builds up in the back of the knee, leading to pain and swelling.
Baker's cysts may not be noticed at first, as small cysts do not typically cause pain. However, as the cyst grows, it may shift the surrounding muscles or put pressure on tendons and nerves, causing pain.
Baker's cysts may grow to about the size of a table tennis ball. People with Baker's cysts often feel pressure in the back of the knee, which may cause a tingling sensation if the cyst is hitting a nerve.
In most cases, Baker's cysts are not a cause for concern, but treatment can relieve the symptoms.
Osteoarthritis is a condition that wears down the cartilage of the joints over time. This condition can easily cause pain in the back of the knee.
People with osteoarthritis in the knee may display other symptoms, such as loss of motion or difficulty bending the knee. Inflammation in the joint may make it stiff and painful. This discomfort may also be felt anywhere around the knee.
Other forms of arthritis that could be causing the pain include autoimmune diseases, such as lupus and rheumatoid arthritis.
Runner's knee is the wearing down of the cartilage in the knee joint. When the cartilage is gone, the bones of the knee rub together. Typically, this causes a dull, aching pain behind the knee.
Other symptoms of runner's knee include:
- the knee giving out or buckling randomly
- weakness in the knee and leg
- restricted movement in the leg and knee
- crackling or grinding feeling when the knee bends
A hamstring injury is a tear or strain in one or more of the muscles in the back of the thigh.
These muscles include:
- the biceps femoris
A hamstring strain happens if the muscle is pulled too far. It may tear completely from being pulled too much and can take months to heal fully.
Hamstring injuries may be more common in athletes who run fast and in bursts, such as those who play basketball, tennis, or football.
The meniscus is a piece of cartilage on either side of the knee. Twisting motions while squatting or bending the leg may tear this cartilage. Many people hear a pop when they tear their meniscus.
The pain from a meniscus tear may not show up at first but worsen over the next couple of days.
Meniscus tears often cause other symptoms, including:
- loss of knee motion
- weakness and fatigue in the knee and leg
- swelling around the knee
- the knee giving out or locking up when used
Surgery may be required if a meniscus tear is severe and does not heal on its own.
The anterior cruciate ligament or ACL is a band of tissue that runs through the front of the knee joint, connecting the bones and helping to keep the knee joint stable.
ACL strains often happen from sudden stops or changes in direction. Similarly to meniscus tears, a strain in the ACL may cause a popping sound, followed by pain and swelling.
A torn ACL is a well-known, serious injury, often side-lining an athlete for a long time. Torn ACLs usually require reconstructive surgery.
The posterior cruciate ligament or PCL plays a similar role to the ACL, though it is less likely to be injured than the ACL.
PCL injuries may happen during traumatic events, such as falling directly on to the knee from a height or being in a car accident. With enough force, the ligament may tear completely.
PCL injuries cause symptoms including:
- knee pain
- stiffness in the knee if bending
- trouble walking
- swelling in the knee
Completely resting the knee may help a PCL strain to heal. A severe PCL injury may require surgery.
Deep vein thrombosis (DVT)
A thrombosis is a blood clot, and a DVT occurs when a clot happens in the veins deep within the leg.
Many people who have a DVT feel more pain when they stand up. Nevertheless, they may feel pain in their leg and knee at most times.
Other symptoms of DVT may include:
- skin that is red or warm to the touch
- swelling in the area
- fatigue in the affected leg
- prominently visible surface veins
Risk factors for DVT can include being overweight, being older, and smoking. People who lead sedentary lifestyles may also experience DVT.
DVT needs medication and care, as it can become more serious if the clot breaks loose into the bloodstream.
It is always a good idea to be sure the muscles around the knee, especially the quads, calves, and hamstrings are stretched properly. This may not protect against some of the traumatic causes of knee pain, but it could help the muscles respond better to activity, every day or otherwise.
The RICE treatment may also help minor to moderate pain in the back of the knee. RICE stands for:
- Resting — the leg
- Icing — the knee
- Compressing — the area with an elastic bandage
- Elevating — the injured leg
In many cases, the RICE treatment may help reduce symptoms, such as pain and swelling.
Nonsteroidal anti-inflammatory drugs (NSAIDs) are another way to ease pain and swelling while the knee is recovering. In some cases, doctors may recommend steroid injections to reduce symptoms.
With more serious injuries, doctors may use an MRI or CT scan to obtain a complete image of the area. They might then suggest treatments that include physical therapy or surgery, depending on the severity.
Pain at the back of the knee may sometimes be a sign of a serious issue. Anyone experiencing severe symptoms or symptoms that last for more than a few days should have their injury checked by a doctor.
Following a doctor's treatment plan may give the injury the best chance to heal correctly and avoid any complications.