6 Causes of Knee Pain From Running—and How To Prevent and Treat It

Whether you're lacing up for your first 5k, training for your next half-marathon, or enjoying a way to get active, running can be a rewarding way to stay fit, get competitive, and escape the stresses of daily life for a little while.

And while pounding the pavement (or the tread!) offers plenty of incredible benefits for your mind and body, it can also often come with less-than-desirable aches and pains. One particularly common complaint is knee pain.

It's no new concept that running is a high-impact exercise, which means your joints have to absorb and react to high levels of force—and repeatedly, explained Thanu Jey, DC, CSCS, Clinic Director at Yorkville Sports Medicine Clinic.

Because your knees bear the brunt of this stress, they're a joint many runners have had some trouble with at one point or another. If you're experiencing knee pain while running, you've got to figure out what is causing it so that you can show your joints the TLC they need to get back out there comfortably and keep logging those miles for years to come.

Reasons You Have Knee Pain While Running

Here are six of the most common causes of knee pain while running—and what you'll need to do to remedy each so that you can run pain-free.

1. Runner's Knee

What causes it: Known amongst doctors as "patellofemoral pain syndrome," runner's knee is usually caused by repetitive motions, poor knee-cap alignment from weak and/or tight leg muscles, and occasionally from poor running form, according to Jey.

Where (and how) it hurts: In cases of a runner's knee, you'll experience pain under your knee cap or at the front of your knee while running, said Sabrina Strickland, MD, a sports medicine doctor at Hospital for Special Surgery. Another dead giveaway: The pain worsens when you're on hills or stairs. Jey described it as a "deep, sharp pain."

How to treat it: Often, a runner's knee is a sign of overuse, which means you'll want to rest it for at least two weeks, said Jey. Once you've done that, run on softer surfaces like grass or sand, and ice after every run as you get back in the game. If it's a persistent issue, you might want to consider working with a physical therapist to address any muscle weaknesses—particularly in your hips, added Dr. Strickland.

How to prevent it: First and foremost, increase your mileage slowly and strategically to minimize your risk of overuse injury, suggested Jey. Otherwise, Dr. Strickland recommended pairing your running with plenty of cross-training, stretching, and resistance training to support balanced muscles.

2. IT Band Syndrome

What causes it: If you have weak hip muscles, your iliotibial band (IT band), a long strip of connective tissue that runs from the outside of your hip to the outside of your knee, deals with extra strain when you run. As a result, it can rub against your thigh bone or knee enough to cause irritation, swelling, and pain, known as IT band syndrome or ITBS. Jumping right into a run without warming up enough can also spell trouble.

Where (and how) it hurts: You'll feel pain on the outside of your knee—and may even notice some popping or clicking sensations there, per HSS.

How to treat it: As with a runner's knee, your best bet for easing ITBS pain is to rest it for at least a week to allow irritation to die down, suggested Jey. Otherwise, foam rolling and stretching regularly is important, added Dr. Strickland. Commit to stretching and foam rolling the outer sides of your thighs at least five minutes per day.

How to prevent it: "A good routine of stretching tight muscles and strengthening hip muscles will do wonders for keeping ITBS from affecting your workout routine," said Jey. Spend a few minutes stretching a few times each day and add hip-strengthening exercises like side-lying abductions and clamshells to your workout and warmup routines.

3. Patellar Tendinitis

What causes it: Also referred to as "jumper's knee," patellar tendinitis is an overuse injury that typically crops up because of the impact of jumping and similar movements, explained Jey. In this case, the patellar tendon, which connects your knee cap to your shin bone) becomes inflamed—and even torn. According to Dr. Strickland, running in worn-out shoes that no longer offer proper support can also contribute.

Where (and how) it hurts: Do you feel pain just below your kneecap? It's probably patellar tendinitis since that's exactly where your patellar tendon attaches to your shin bone, said Jey. People with this issue might also notice pain when they first start running, get up from sitting down, or stretch, added Dr. Strickland.

How to treat it: As always, ice and rest are your first step when dealing with a jumper's knee, said Jey. From there, Dr. Strickland recommended checking whether you need new running shoes, while Jey recommended considering wearing a knee brace that can lessen some of the force put on your patellar tendon.

How to prevent it: For good measure, Dr. Strickland recommended changing your running shoes every 250 to 300 miles. In your actual training, adding quad-strengthening exercises to your routine (think squats and leg extensions) can help protect your patellar tendon from future trouble.

4. Arthritis

What causes it: In arthritis, the articular cartilage—a smooth, shiny covering on the bones of our joints—wears down, explained Dr. Strickland. For many people, this occurs due to years of wear-and-tear on the body or traumatic injury that leads to joint pain, added Jey.

Where (and how) it hurts: Arthritis can affect any part of your knee—but it's most commonly seen on the inside of the knee, according to Jey.

How to treat it: Healthcare providers typically use anti-inflammatory medications and steroid injections to treat arthritic knees. However, as Jey said: "Motion is lotion. When you have arthritis in the knee, it is important to keep active. Swimming is a great way to keep moving while putting less stress on your joints."

How to prevent it: While there's no guaranteed way to prevent arthritis, limiting the stress put on your knees is your biggest bet in avoiding the pain. One way to do this is to maintain a healthy weight, as being overweight means more impact on your knees every time you move, let alone run.

5. Poor Form

What causes it: If you have imbalances in the muscles involved in running—whether strength imbalances or uneven levels of tightness—they can throw off your form and ultimately put extra stress on your knees, said Jey. Of course, exactly what these imbalances look like—and how they mess with your form and knee health—varies from runner to runner.

Where (and how) it hurts: Since there are so many flavors of poor form, knee pain caused by them is equally variable. "It can hurt anywhere in the knee joint," said Jey. "However, you'll usually feel it on the inside of the knees or within the knee cap."

How to treat it: Good form is crucial if you want to run pain-free for life, so see a physical therapist who works with many runners, suggested Dr. Strickland. They'll analyze your gait to identify exactly what's going on and prescribe strengthening exercises to help you regain balance.

How to prevent it: If you're just getting started with running or are planning to up your mileage, get ahead of the game by seeing a PT or running coach who can check your form and give you any necessary tips or corrective exercise suggestions before you ramp up, our experts recommend.

6. The Wrong Shoes

What causes it: Though there's plenty of variation here, knee pain resulting from wearing the wrong shoes often stems from a lack of arch support. In this case, your feet tend to overpronate or fall inward, which then causes your knees to bow inward, putting more stress not only on your knees but on your ankles and hips, too, explained Jey.

Where (and how) it hurts: Pain anywhere in your knee could indicate you need different shoes—but in the case of overpronation due to shoes that aren't supportive enough, you'll likely feel pain on the insides of your knees, said Jey.

How to treat it: Head to your local running store or even a podiatrist for recommendations of running shoes that deliver on arch support. If you're struggling, consider custom orthotics, which will offer support exactly where you need it most, suggested Jey.

How to prevent it: Sometimes finding the right running shoes for your feet takes trial and error, said Dr. Strickland. However, spending the time (and money) at a reputable running shoe store can help eliminate some of that.

When Should You Stop Running Because of Knee Pain?

As tempting as it may be to push through discomfort, "any level of knee pain can be an indicator that you should stop and further examine the cause," said Jey. Otherwise, you put yourself at risk for more issues down the line. Plus, if your cranky knees are the result of taking your running from zero to 100 too quickly, rest (and a healthy reevaluation of your routine) might be just what you need to kick your pain to the curb.

"If you are sore for a day or two as you ramp up your running program, that is fine, but joint pain is not normal," said Dr. Strickland. So go ahead and drop that "no pain, no gain" mentality.

When Should You See a Healthcare Provider?

If running is a significant part of your life (or you'd at least like it to be!), safe is better than sorry when it comes to taking knee pain seriously. "If your pain does not go away after exercise or is persistent every time you perform an activity, it is worth getting the knee evaluated," said Jey. "This will also help prevent further damage, which could keep you out for extended periods of time."

Another key indicator that it's time to see a pro, according to Dr. Strickland, is swelling. Unexplained knee swelling can indicate a serious health concern, so don't let it go unchecked.