7 Signs That Your Knee Injury is Serious | What to Look For

One of the most common injuries is a knee injury, but not every knee injury is serious. On the other hand, if you do have a knee injury, it's important that you get it treated right away. Serious knee injuries can lead to more problems for your legs.

But, how do you know if your knee injury is serious? It can be hard to tell which injuries are serious and which ones can severely harm your body long-term. That's why we're going to take a look at 7 signs that tell you your knee injury is serious.

Are you ready? Let's go!

Common Knee Injuries

Common knee injuries can vary depending on many factors, such as your activity level, age, weight, and gender. You can also consider the location of your knee injury, such as the lateral (outer) side, medial (inner) side, posterior (behind) side, or anterior (front) side.

Considering each of these variables can help determine if your knee pain is serious and your injury involves any tendons, ligaments, or bone. While knee sprains and strains may have excruciating pain in the moment, they are often not considered serious and can be treated over time with certain interventions.

Here are some common knee injuries you might run into:

• Bruising
• Fractures
• Dislocations
• ACL Issues
• PCL Issues

These are some of the most common knee injuries that one might encounter. However, just because they're common doesn't mean they're not serious. Most of these common knee injuries are pretty serious and can lead to long-term issues if not treated properly. 

How Do I Know If My Knee Pain is Serious? 

In order to rid yourself of annoying knee pain that may be hampering your exercise routine or your ability to do your job effectively, you must first identify the root source of your pain.

There are plenty of signs that you can identify to know if your knee pain is serious. Here are 7 signs that your knee injury is serious. If you have any of these signs, you should seek treatment as soon as possible. 

7. Knee Swelling After Fall or Hit

A fall or hit qualifies as an acute injury, or a sudden onset injury. With acute injuries, one of the first symptoms to check for is knee swelling.

Knee swelling may not be instantaneous after a fall or hit, but it’s important to continually check on your knee swelling from onset to 48 hours after you sustain the injury.

The swelling occurs because of excess fluid accumulating at the site of the injury, and your knee may also have discoloration as a result of the swelling.

While knee swelling after a fall or hit is a definite sign or injury, it does not tell the full story yet if your knee pain is serious.

6. You Felt or Heard a Pop in Your Knee

If you felt or heard a pop in your knee, it could be both moderate or serious. The symptoms that appear afterward will indicate your subsequent steps.

If you felt or heard a pop in your knee and it’s painful and/or appeared in the moment of acute trauma/injury, you should seek a doctor’s diagnosis to make sure there is no ligament tear.

Ligament tears, such as the ACL, often require surgery and a lengthy recovery process. On the other hand, if there is no associated pain or instability in the moment of the pop, it could indicate the rubbing of structures inside your knee, known as crepitus.

Or it could be gas bubbles producing a popping phenomena, similar to cracking your knuckles. So if you felt or heard a pop in your knee, assess the circumstances of the pop, and you will have more information if your knee injury is serious.

5. It Feels Impossible to Bear Weight on Your Knee

Inability to bear weight on your knee or feeling as if your knee will give out is a sign of instability in your knee. This symptom can be a sign that you have a moderate to severe knee injury.

If any of your knee structures, such as your patella tendon, ACL, MCL, meniscus get injured, the body will restrict movement at the injury site in order to protect the body from further injury and pain.

This results in feeling impossible to bear weight on your knee, as your body is essentially sounding the alarm that you need to avoid putting pressure on the injured knee.

4. You Can’t Walk Correctly

Being unable to work correctly is also suggestive of a lower body injury. When suffering a knee injury, you will have a tendency to lean towards the uninjured side in order to avoid putting pressure on the injured knee.

This compensation technique will cause you to limp, and walk in an abnormal gait. The mere fact that you are able to bear weight on your knee (even with a limp) is a good signal that your knee injury is minor to moderate.

And since you are able to walk, albeit inefficiently, keeping your injured knee moving in pain-free zones, will help you recover faster.

3. You Can’t Fully Extend Your Knee

If you can’t fully extend your knee, it’s important to recognize whether that is the result of an acute injury or a chronic injury. If there was an acute injury, the inability to fully extend your knee can be a result of inflammation, which inhibits your ability to recruit your quadriceps or hamstring muscles to perform the knee extension.

If you have a chronic injury and you can’t fully extend your knee, you may be dealing with osteoarthritis, which is the wearing and tearing of knee cartilage, or a meniscus tear. Your meniscus is cartilage that acts as a shock absorber for your knee, and if damaged, it can affect your knee health long-term. 

2. Your Knee Feels Locked

A locked knee is characterized by the inability to bend or straighten your knee, like having a “stuck” feeling. If your knee feels locked, there is often a biomechanical issue to blame.

One of your knee structures is physically getting stuck, and impeding movement. For example, your knee is in between your upper leg femur bone and your lower leg tibia bone.

When you move your body, if your upper leg femur bone is moving efficiently, but your lower leg tibia bone is moving slower, the knee gets caught in the middle and may “lock” to discourage extraneous motion that may cause injury.

A locked knee is essentially a defense mechanism intended to inhibit movement of the knee so that no further harm can be done.

1. Long-Term Knee Pain or Discomfort

Long-term knee pain or discomfort normally indicates a severe injury or the need for diagnostic imaging. Since there was no sudden onset of symptoms from a fall or a sports injury, long-term knee pain or discomfort means your knee is not functioning properly.

However, not functioning properly can encompass many variables. For example, if you injured your other side awhile ago, and were limping onto your “good” side, that may have caused a ripple effect and caused an injury to your good side by putting too much weight on that knee.

That’s why it’s important to seek diagnostic imaging and/or a doctor’s opinion, so they can determine steps to resolve your long-term knee pain or discomfort.

Final Thoughts

There are endless ways in which the knees can be damaged and injured. Yet in nearly all cases of knee pain, symptom identification is the first step towards understanding if your knee pain is serious. While recognizing whether you are positive or negative for certain symptoms can be beneficial, a physical examination, along with tests such as x-rays or MRI, can help your doctor or physical therapist discover the foundation of your knee pain and recommend the best treatment for your individual injury.