Are you worried about feeling uncomfortable on the backside of your knees or feeling particularly swollen below your knees? When these symptoms occur, there may be a problem with lymph flow.
This time, we will explain in detail the causes and treatments for unpleasant symptoms around the knees.
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What is the condition of "swelling and pain on the back of the knee"?
If the back of your knee is noticeably bulging, it may be because the synovial fluid in the knee joint is being pushed backwards. At first, swelling and lumps may be noticeable, but as they grow, they may put pressure on nearby nerves, causing pain.
In addition, if the flow of lymph fluid is obstructed due to various reasons and circulation problems occur, swelling below the knees may become noticeable.
Specific diseases and symptoms
Below, we will introduce specific diseases and symptoms. Let's compare the symptoms that are similar to yours.
Baker's cyst (popliteal cyst)
This is a mass in which too much synovial fluid accumulates inside the joint capsule, causing the joint capsule to bulge backwards, creating a lump-like appearance. If you notice that the back of your knee is getting bumpy all the time, this is probably the first symptom you should suspect.
Why does the back of the knee swell?
A joint capsule is a bag-like tissue that covers a joint where bones connect. Think of it like a soft balloon that wraps around your joints. It contains a fluid called synovial fluid that protects the joints.
When the knee becomes inflamed, excess synovial fluid is produced to protect the knee. The joint capsule is a soft tissue like a balloon, so it expands when there is a lot of synovial fluid inside.
The front part has the patella, so it cannot expand structurally, but the rear part has room to expand because there is a small gap between the gastrocnemius muscle (calf muscle) and the semimembranosus muscle (muscle at the back of the thigh). Also, since the back side has a particularly stretchable structure, it naturally bulges out at the back, giving the appearance of a lump.
Cases prone to Baker's cyst
It may occur if you have an existing disease such as rheumatoid arthritis, knee osteoarthritis, or meniscus injury. The same goes for people who overwork their knees.
In particular, in the case of rheumatoid arthritis, both domestic and international studies have shown that the complication rate is extremely high, with reports showing that Baker's cyst was confirmed in nearly half of the cases.
Having a cyst does not necessarily mean that you will experience a lump, discomfort, or pain behind your knee, so you may live your life without realizing it.
treatment
The basic approach is to rest to prevent synovial fluid from accumulating, or to use anti-inflammatory drugs to reduce pain.
If the cyst is large and the symptoms are severe, arthrocentesis may be performed to drain excess synovial fluid with a needle. If symptoms recur, surgery may be an option.
knee osteoarthritis
Knee osteoarthritis is a disease in which the cartilage in the knee wears away, causing the bones to rub against each other.
Early symptoms include knee pain, stiffness, and swelling. As the condition progresses, the pain when bending and straightening the knee becomes stronger, and in some cases, even just standing becomes painful, making walking difficult.
Why does swelling and pain occur below the knee?
Additionally, due to wear and tear on the cartilage, excess synovial fluid is produced within the joint, which accumulates throughout the knee, especially at the back of the knee, causing swelling and pain. The difference between Baker's cyst and Baker's cyst described above is that Baker's cyst is caused by synovial fluid collecting inside the joint capsule, while knee osteoarthritis is caused by the accumulation of synovial fluid inside the joint capsule. Synovial fluid may accumulate in the.
It is the latter that is generally said to have "water collecting" in the so-called joints.
If you press the patella with your knee extended, it will sink downwards, so it is easy to tell by self-checking.
In addition, joint instability can put excessive strain on the muscles and ligaments behind the knee when walking, which can cause pain. Additionally, impaired blood and lymph circulation due to inflammation can cause swelling below the knee.
Cases prone to knee osteoarthritis
Risk factors include older age, obesity, and previous knee injuries. However, epidemiological studies have shown that nearly half of people over 40 have it (42.6% of men, 62.4% of women), so it is not a rare disease.
Furthermore, it is said that 2 to 3% of the population will develop new knee osteoarthritis every year, so it is good to understand that anyone can develop knee osteoarthritis.
treatment
The basics are exercise therapy (muscle training and stretching), lifestyle guidance including weight management, and physical therapy (warming with hot packs, cooling with ice packs, etc.).
If fluid is present, arthrocentesis may be an option, but this is only a temporary measure unless the cause of the excess synovial fluid is removed.
If the symptoms are severe, such as the inability to walk, surgery may be an option.
deep vein thrombosis
This is a disease in which a blood clot (thrombus) forms in the veins deep in the legs.
People who are forced to stay in the same position for long periods on airplanes may develop blood clots in their legs, and the blood clots can sometimes travel to the lungs, a condition commonly known as ``economy class syndrome.'' However, it is important to keep in mind that deep vein thrombosis is not limited to airplanes and does not necessarily end up in the lungs.
Symptoms include swelling, pain, redness, and warmth in the legs. Additionally, if a blood clot that forms in the leg flows into a blood vessel in the lungs, it can cause a pulmonary embolism, which can cause difficulty breathing and can be life-threatening.
Why does swelling and pain occur below the knee?
In deep vein thrombosis, a blood clot blocks blood flow in a vein. This causes blood to pool in the legs, causing swelling, especially below the knees (often noticeable as swelling throughout the legs). In addition, the inflammatory reaction and pressure caused by the blood clot can cause pain throughout the leg, including the back of the knee. Also, if a blood clot forms in the popliteal vein (the main vein that runs behind the knee), pain in the back of the knee may become noticeable.
Cases prone to deep vein thrombosis
Risk factors include staying in the same position for long periods of time, resting after surgery, and obesity.
It is also more likely to occur due to poor blood circulation, such as heart failure.
treatment
Ultrasound (echo) examinations and CT examinations are used for diagnosis, and anticoagulants are mainly administered for treatment. It's a so-called blood thinning medicine. Surgery is rarely performed.
lymphedema
Lymphedema is a condition in which fluid accumulates in tissues due to impaired lymph drainage.
It starts with mild swelling, but as it progresses, severe swelling and hardening of the skin occur.
Why does swelling and pain occur below the knee?
This is because swelling tends to occur particularly in the lower limbs, which are more susceptible to the effects of gravity, and the structure of the lymph nodes. Lymph vessels in the lower limbs ascend from the ankles to the knees and the base of the feet. When lymph flow is impaired, lymph fluid begins to accumulate in the most distal areas, such as the ankles and calves, below the knees. However, in the case of lymphedema, swelling is often noticeable all the way to the thighs.
In addition, tissue compression and inflammatory reactions caused by swelling can cause pain and discomfort throughout the leg, including the back of the knee.
Cases prone to lymphedema
Causes include lymph node removal during cancer treatment, radiation therapy, and infections.
Even in the case of deep vein thrombosis described above, the blood clot may press on the lymph vessels and directly cause lymphedema.
treatment
These include lymphatic drainage to improve the flow of lymph, compression therapy (using compression stockings, etc.), and exercise therapy to reduce swelling using the pumping action of muscles.
summary
Swelling and pain behind the knee and swelling below the knee can be caused by a variety of factors, including synovial fluid and problems with the lymphatic system. In some cases, it may not be possible to cope with muscle training or painkillers. If your symptoms are severe or persist for a long period of time, it is important to consult a specialist immediately to discuss the best way to care for your knee.