What Causes Knee Pain: Causes, Symptoms, & Treatments | PT Effect

What Causes Knee Pain and How Can I Treat It?

Knowing the cause of knee pain can help guide you to the right treatment
Read Time: 5 minutes
Jul 12, 2021

Millions of Americans deal with knee pain daily. For some, it’s bad enough to impair their ability to function and perform daily activities. Some people even need knee replacement surgery. For others, the pain is mild but prevents them from being as active as they want to be. The severity and type of knee pain depends on the cause of the knee pain.

But what causes knee pain and how can it be fixed?

What Causes Knee Pain?

There are a variety of different injuries and conditions that can cause knee pain. Some of the most common causes of knee pain include:

  • Meniscus tears
  • Injury to the knee ligament
  • Arthritis in the knee:
    • Rheumatoid arthritis
    • Osteoarthritis
    • Post-traumatic arthritis

Meniscus Tears

Woman holding knee in pain

The menisci are cartilage in the knee. There is the medial meniscus, which is located on the inside of the knee. The other type is the lateral meniscus, which is on the outside of the knee. Meniscus tears are common injuries that can cause knee pain.

Symptoms of a Meniscus Tear

The symptoms of a meniscus tear include:

  • A popping noise
  • Pain in the knee
  • Knee locking up
  • Knee giving out
  • Knee stiffness

Often after a meniscus tear, you experience initial pain but are able to walk. In the days following the injury, however, the pain can get worse and the knee may stiffen up.

Treatment for Meniscus Tears

To treat a meniscus tear, you should rest, avoiding any activities or movements that make the pain worse. You can help reduce swelling by icing the injured knee. If the knee pain is severe, you can take over-the-counter pain medication and use crutches to avoid using the knee while walking

Physical therapy is also a good treatment for a torn meniscus. Physical therapy exercises can help to support the injured knee by strengthening the muscles around it as well as in your legs. Surgery is usually a last-resort treatment if the injury isn’t healing.

Injury to the Knee Ligament

Your knee is connected to the thigh and shin bones with the ACL, LCL, PCL, and MCL. The ACL is the largest of these ligaments and is in the middle of the knee joint. It’s also the most commonly injured of the knee ligaments. ACL sprains and tears can occur when exercising or playing sports.

The following motions can result in ligament injuries

  • Quickly changing directions
  • Landing incorrectly after a jump
  • Starting suddenly
  • Stopping suddenly
  • A collision with another person

Symptoms of a Knee Ligament Injury

The symptoms of an injury to the ligaments in the knee, especially the ACL, include:

  • A popping sound
  • Sudden pain in the knee
  • Severe pain in the knee
  • Knee giving out
  • Pain while walking
  • Swelling in the knee

Treatment for Knee Ligament Injuries

The first step in treating an injury to a knee ligament is to rest the knee. Avoid any movements or activities that cause pain. This may mean using crutches to avoid putting your weight on the injured knee. You can ice the knee to help bring down swelling and wear a knee brace to help stabilize. Over-the-counter anti-inflammatory medication can also be used to help with the pain and swelling.

Physical therapy can help treat a knee ligament injury as well. There are stretches and strengthening exercises that a physical therapist can guide you through to help support the knee joint. These stretches and exercises can then be repeated at home.


Arthritis is a chronic health condition that causes inflammation in joints throughout the body. It’s most common in the knees. Many people develop arthritis in their knees as they age because the cartilage in the knees wears down over time.

Knee illustration with and without arthritis

There are three types of arthritis that commonly affect the knees

  • Rheumatoid arthritis
  • Osteoarthritis
  • Post-traumatic arthritis

Symptoms of Arthritis

The symptoms of arthritis are similar across all three common types:

  • Stiffness
  • Swelling
  • Pain
  • Difficulty fully bending the knee

Treatment for Arthritis

Arthritis, whether it’s caused by an injury, age, or other stresses on the knee, is typically treated with a combination of anti-inflammatory medication and physical therapy. If those treatments don’t work, surgical replacement of the knee may be considered as a last resort.

Get Relief for Your Knee Pain

If knee pain is interfering with your daily life it may be time to seek out professional help. Our doctors of physical therapy can help you achieve lasting relief. With focused, one-on-one physical therapy we get to the root cause of your pain and eliminate it at the source. Contact us to schedule your first appointment.

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Mark Shulman

Dr. Mark Shulman

Doctor of Physical Therapy (DPT), FAAOMPT, COMT, CSCS


Fellow of the American Academy of Orthopaedic Manual Physical Therapists.

Mark Shulman

Dr. Allison McKay

Doctor of Physical Therapy (DPT), PRPC


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