Numbness is a symptom that can cause a loss of sensation and tingling in the knee joint. Sometimes, this numbness and tingling can extend down or up the leg.
There are multiple potential causes of numbness in the knee, from an acute injury to a chronic condition. Read on to learn more about the causes, additional symptoms, treatments, and more.
Many nerves are present in your body that are responsible for initiating movements and sensing touch, temperature, and more. Damage and compression to these nerves can cause numbness.
Outside nerve compression
Sometimes, outside forces pressing on the leg and knee can lead to numbness. This is true when a person wears tight clothing, knee braces, or compression hose that extend up the thigh.
If the clothing is too tight and cuts off a person’s circulation or presses on a cutaneous nerve, numbness can result.
A person can also experience temporary knee numbness due to the position of their leg. Compression in stirrups, such as for a pelvic exam or surgery, can press on nerves. Even crossing your legs for too long can cause knee numbness.
Acute injuries to the kneecap, leg, and behind the knee can all cause knee numbness.
For example, an anterior cruciate ligament (ACL) injury can cause swelling and inflammation that leads to knee numbness.
Arthritis is a condition that causes inflammation and swelling in the joints. It especially affects the knee joints because they’re subject to a lot of wear and tear from daily activities and exercise.
Some people with arthritis experience altered sensory perception. In addition to pain, a person can experience numbness and tingling.
Having diabetes can lead to nerve damage that doctors call diabetic neuropathy. While there are different types, peripheral neuropathy affects the nerves of the feet and legs.
Diabetic neuropathy symptoms usually start in the feet. They include tingling, numbness, weakness, and pain. In some people, these symptoms extend to the knees.
Fibromyalgia is a condition that causes muscle pain and fatigue for unknown reasons. It doesn’t damage the joints like arthritis does, but it can cause similar symptoms that include muscle pain and numbness.
Some people with fibromyalgia have tender points, which are areas of the body that may feel painful, numb, or reactive to touch. The knees are one of these areas.
Radiculitis is inflammation of one or more of the nerves that exit the spinal column. Narrow spinal canals, a spinal disc that’s out of place, or arthritis where the spinal bones can start to rub together are all common causes of radiculitis.
Because the nerves that leave the spine can run down the leg, it’s possible inflammation in the back can lead to tingling and numbness in the knee as well. As the condition worsens, some people find their legs feel weaker.
Surgery on the knee
Some patients who have had a total knee replacement may experience knee numbness. A surgeon may accidentally injure the saphenous nerve located near the kneecap during surgery.
In addition to numbness in the knee, you may have other symptoms that affect your legs and back. These symptoms include:
- changes in body temperature sensation, such as the skin feeling very hot or cold
- knee pain
- pain that extends from the buttocks throughout the leg
- weakness in the legs
Often, your symptoms can help guide a doctor as to potential causes.
Treatments for knee numbness usually depend on the underlying cause. A doctor’s goal is to usually treat with conservative measures before recommending more invasive surgical approaches.
For example, some at-home tips to reduce knee numbness and inflammation can include:
- Taking an over-the-counter anti-inflammatory drug, such as ibuprofen (Advil) or naproxen sodium (Aleve).
- Icing the knee with a cloth-covered ice pack for 10-minute intervals.
- Elevating the legs to promote blood flow back toward the heart and reduce swelling.
- Resting the affected knee, especially if it’s visibly swollen.
In addition to home care measures, a doctor may prescribe certain medications, depending on your medical condition.
For example, a doctor may prescribe medications to improve nerve transmission in people with fibromyalgia and diabetic neuropathy. These medications include gabapentin (Neurontin) and pregabalin (Lyrica).
Doctors may also prescribe corticosteroids or antidepressants, which can help reduce nerve pain in those with fibromyalgia.
If knee numbness is the result of an injury or compression on the spinal nerves due to a herniated disk, a doctor may recommend surgery. A surgeon can remove damaged disk material or a portion of bone that’s pressing on the nerves.
To prevent knee numbness and related symptoms:
- Avoid crossing your legs for long periods of time. Instead, keep your feet flat on the floor, or elevate them on a chair or bench.
- Avoid wearing tight clothing, like tights, certain pants, and leggings. You should also avoid wearing too-tight compression stockings, or those that give your feet the pins-and-needles feeling.
If you wear a knee brace and often find it causes knee numbness, talk to your doctor. There could be another way for you to wear or adjust it.
Many people find maintaining a healthy weight cuts back on knee numbness. The knees have to bear a lot of weight, which can lead to inflammation.
If you have difficulty with knee pain and numbness, try exercising in a pool. The water takes pressure off the joints, but it still allows you to burn calories.
If you have diabetes, maintaining control over your blood sugar can help reduce nerve damage risks. Your doctor may want to adjust your medications if your blood sugar is consistently too high.
Numbness in the knee is rarely a medical emergency, but there are a few exceptions.
Compressed nerves in the spine
The first is a condition called cauda equina syndrome. This condition occurs when something compresses the nerve roots in the back so much that a person has extreme numbness and tingling in their legs. They may also experience bowel and bladder incontinence.
Usually, a severe herniated disk causes cauda equina syndrome. It can be a medical emergency because a surgeon needs to take pressure off the nerves before they’re permanently damaged.
Another medical emergency that can cause numbness in the knee is a stroke.
Although a rare symptom of a stroke, it’s possible a person can experience numbness in their knees and legs. Other symptoms may include facial drooping, confusion, severe headache, difficulty moving one side of the body, and dizziness.
A stroke, or a “brain attack,” occurs when the brain doesn’t get enough blood flow. If you or someone around you is having a stroke, call 911 immediately.
As mentioned above, knee numbness can be the result of an injury. If you’ve recently been injured and experience loss of feeling, tingling, or pain in your knee, consult a medical professional right away.
If you have knee numbness, the cause could be as simple as compressing the nerve with your clothing or by crossing your legs. However, it can also be caused by a medical condition or injury.
Talk to your doctor if you have knee numbness that affects your mobility and interferes with your daily activities. Usually, the earlier a doctor treats a condition, the better your results.