Everything You Need to Know About Knee Pain: Common Causes, Symptoms, and Diagnosis

Fact checked by Olga Sadouskaya, MD
Clinical Pharmacologist, Chief Medical Officer

Knee pain affects people of all age groups. You may have knee pain when walking, running, or jogging, and it can sometimes result in weakness, numbness, or a tingling sensation.

When it comes to knee pain, the severity and location of the pain may vary, but there are some general signs and symptoms that characterize the pain. They include:

  • Knee pain and weakness
  • Swelling and stiffness
  • Popping or crunching noises
  • Inability to fully straighten the knee
  • Instability

Research shows that most knee pain can usually be remedied at home, except in extreme cases when surgery is required to fix the issue. While some knee pain may not respond to treatment, there may be several potential remedies for relief.

5 Common causes of knee pain

Knee pain can result from different things. Below are five of the most common knee pain causes:

  • Strain and overuse: When there is strain around the knee, it is usually due to overuse. This may come from stressing the muscle around the knees, heavy lifting, or a sudden injury.
  • Tendinitis: Tendinitis is irritation and inflammation of the thick fibers that connect muscles to bones (tendons). This soreness can result from an injury to the patellar tendon, which joins the patella to the shinbone and allows you to run, jump, and kick. Running, skiing, biking, and jumping-related sports and hobbies can all result in patellar tendonitis.
A man having knee pain after running
  • Torn ligament: The knee has four ligaments around it. Knee pain can arise when there is a tear in any of them, the most commonly injured ligament being the anterior cruciate ligament. This type of injury is most common in people who play sports that require them to turn suddenly such as basketball, soccer, etc.
  • Bursitis: A bursa is a sac under the skin above your joint that contains a small amount of fluid. As the joint moves, it lessens friction. The bursa on top of your kneecap might become irritated by overuse, accident, or frequent bending and kneeling. This can cause discomfort and swelling. Prepatellar bursitis is the term used by physicians to describe this type of condition. It’s also known as “preacher’s knee.”
  • Arthritis: Inflammation and pain are symptoms of arthritis. Chronic arthritis might get worse over time and finally necessitate surgery. Rheumatoid arthritis, post-traumatic arthritis, and osteoarthritis are the three most prevalent kinds of arthritis.

What causes knee pain at night?

Knee pain at night may have various causes, such as injury, runner’s knee, bursitis, etc. Most knee pain experienced at night is temporary and can easily be treated or relieved by a doctor. But in the case of osteoarthritis, it is usually permanent and persistent, as there is no cure for the condition.

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Osteoarthritis has also been known to cause an increase in pain when the affected leg is in a state of rest. This is one major reason why it occurs at night. Although it may have no cure, it can be managed, and the pain can be relieved by a doctor.

Symptoms of common knee problems

The symptoms of knee problems differ for each person, and often, the cause of the knee pain determines the kind of pain each individual feels. There are some general symptoms that indicate the presence of knee pain, sometimes called a knee pain symptom checker, and they are as follows:

  • Burning discomfort
  • Constant aches in the area
  • Sharp and intense pain when the knee is in use
  • Chronic swelling and redness if touched
  • Knee pain and cracking
  • Knee pain and clicking

Knee pain after running: Injury or arthritis?

Running does not cause arthritis, although you may be experiencing knee pain when running. This kind of pain can be due to injury, runner’s knee, or arthritis. So what is the difference between the last two conditions?

Runner’s knee, which is also known as patellofemoral syndrome, is usually experienced as pain at the front of the kneecap. It can be caused by intense exercise such as squatting or jogging. Sometimes, there is a combination of knee pain and numbness occurring at the same time.

It is more common for people who do not participate in sports. The kneecap goes out of place, causing pain.

This pain is evident when you move, climb the stairs, or try to play some sports.

Arthritis, on the other hand, can happen in different parts of the body. It is common in people older than 50, and due to its wear-and-tear nature, it can be extremely painful. Arthritis causes the bones to rub on each other, which can be painful.

Doctors can easily tell the difference between these two conditions by conducting a physical examination. Ultimately, runner’s knee can be treated through rest, compression, or putting ice on it. On the other hand, arthritis cannot be cured, but steps can be taken to reduce the pain.

A woman applying an ice pack to her knee to relieve knee pain and numbness

How is knee pain diagnosed?

People often wonder how knee pain diagnosis is conducted. Aside from a physical examination of the knee and your medical history, the doctor may use a knee pain chart. This chart shows the causes of knee pain and possible diagnoses, depending on the pain location and its severity. Other methods are:

  • X-rays: These are frequently used to diagnose certain illnesses and aches in the body. X-rays create images of tissues, bones, and organs using invisible electromagnetic energy beams and display them on film.
  • A radionuclide bone scan: This is a nuclear imaging technique that uses a small amount of radioactive material. This radioactive material is injected into the bloodstream and then shown on a scanner. It shows blood flow to the bone and the activities of the cells within the bone.

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  • Computed tomography scan (CT or CAT scan): This test takes various images of the body using a combination of X-ray and computer technologies. A CT scan allows for detailed viewing of every part of the body, including the bones, muscles, fat, and internal organs. CT scans are more thorough than standard X-rays.
  • Magnetic resonance imaging (MRI): As the name implies, this diagnostic method utilizes large magnets, radio frequencies, and a computer to make detailed images of the organs inside the body. The test can also be used to determine the damage or disease in the surrounding areas.
  • Arthroscopy: Of all the ways knee pain can be diagnosed, this method is one of the most invasive. It is a combination of diagnostic and treatment methods. A small incision is made in the joint, and a small lighted camera, called an arthroscope, is inserted into the incision. The arthroscope can evaluate the degenerative or arthritis-related condition and detect cancer, inflammation, and other causes of pain.

Knee pain can be annoying and affect your quality of life, so it’s best not to take matters into your own hands by self-diagnosing. So, when do you need to see a doctor?

When to see a doctor

Whenever you have knee pain that doesn’t resolve on its own, you should see a doctor. You may be referred to a medical rehabilitation specialist or physiotherapist. If you’re having knee pain, it’s particularly important to see a doctor when:

  • There is severe pain or when knee pain is serious.
  • The painful knee is swollen.
  • You can’t move your knee.
  • The knee doesn’t get better after a few days.
  • You can’t put any weight on the knee.
  • The knee locks, clicks painfully, and gives way.
  • There is persistent knee pain and tingling in the foot.

Wrapping up

Due to the different types and causes of knee pain, you may need to consult your doctor to determine the kind of knee pain you are dealing with and the possible solutions. Diagnosis may be possible simply by examining the knee and symptoms. In some cases, further tests are carried out to confirm the diagnosis. Your doctor will recommend the best tests and treatment for you. With this information, you now know what to expect from such a visit.

January 19, 2023