Any joint can become painful, but one of the toughest to deal with is the knee. Because they must support your body weight day in and day out, the knees gets a lot of use.

So, when knee pain strikes, it can be debilitating, affecting your day-to-day movement.

The complex structure of the knee joint can make it especially susceptible to injury and wear-and-tear.

“A knee joint consists of ligaments, cartilage and bone surrounded by muscles and tendons that can help the joint move. Knee pain can be a result of injury to any of these components,” notes Shelby York, a physical therapist with the Ohio State University Wexner Medical Center in Columbus.

Most people will experience knee pain at some point, and the reasons why may vary depending on your age.

Younger adults “commonly experience knee pain due to acute injuries or overuse from intense exercise,” says Dr. Daniel Diaz, a sports medicine specialist and medical director of sports medicine at AltaMed Health Services in Los Angeles. However, for older adults, those issues plus age-related causes, such as arthritis, are often the culprit.

The most common causes of knee pain include:

Knee tendonitis is a source of knee pain that’s “typically caused by overuse injuries, commonly found in runners or other athletes,” explains Dr. Taylor Dunphy, an orthopedic surgeon and sports medicine specialist with Hoag Orthopedic Institute in Southern California.

Tendonitis can affect the hamstrings (the back of the thigh), quadriceps (the front of the thigh) and patellar (knee cap) tendons. In particular, the iliotibial band – also referred to as the IT band, which runs from the hip to the outside of the knee – can become tight and inflamed from overuse, causing knee pain.

“This pain is usually achy in nature and is worsened with activity,” Dunphy says.

Tendonitis isn’t often debilitating, he adds, but it can lead to more chronic pain.

The three most common sites of knee pain from sports include:

Arthritis in the knee is considered a “wear-and-tear” problem in which the knee’s natural shock absorber – the cartilage – is compromised. This happens when the cartilage that lines the ends of the two bones making up the knee joint start to thin and bring the bones closer together, eventually causing them to rub against each other. The result is dull pain, swelling and reduced mobility of the joint.

“The thinning or wear can be very mild or severe,” Calabrese says.

Knee arthritis is common, typically has a slow onset and is progressive in nature.

Less frequently, knee pain can also stem from medical conditions, including:

No matter what’s causing the knee pain, there are some strategies you can try to alleviate it. Targeted at-home exercises are some of the most effective means of strengthening the muscles and ligaments around the knee to help support improved function and healing.

Stand in front of a wall with your hands placed on it for support. Slowly, step backward until you feel a gentle stretch along the back of your calf. Making sure your heels are flat on the floor, hold that position for 30 to 45 seconds, then return to upright standing, Calabrese says. Perform this stretch three to five times.

Stand with support by placing your hands on a table. Then, raise up on your toes for a two-second count while keeping equal pressure on both legs. Lower slowly at a four-second count. Relax, and repeat the exercise 12 times, one to three times a day.

To strengthen the hip muscle, lie on your side with your knees bent at a 45-degree angle. Place a pillow between your knees, and rest your head on your lower arm.

“Be sure that your hip bones are stacked on top of one another, as there is a tendency for the top hip to roll or rock backward,” Calabrese advises.

Keep your feet touching while raising your upper knee as high as you can without shifting your hips or pelvis. Keep your lower leg on the floor, and slowly return to the starting position. Relax. Do 12 repetitions, three times a day.

While lying on the floor, bend your knees to a comfortable angle of about 90 degrees while keeping your feet flat on the floor. Lift both your hips up toward the ceiling. You can also do this exercise while putting a mini-band around the knees, Calabrese says. Do three sets of 10 repetitions.

This exercise can help strengthen your glutes, hamstrings, quadriceps and calves to battle general knee pain, says Madison Franek, a physical therapist with UNC Health in Chapel Hill, North Carolina.

Begin by standing with the affected leg on top of a 4- to 6-inch step and the unaffected leg on the ground, with the toes up so they aren’t touching the floor. If balance is an issue, stand next to a steady object, such as a handrail, that you can use for support.

In a controlled fashion, step up with the affected leg by imagining you’re driving your foot through the step to the ground. With your unaffected leg, reach back in a controlled manner toward the ground and repeat. After stepping up, reach back with your unaffected leg toward the ground in a controlled manner and repeat. Aim to do two or three sets of six to eight repetitions.

This exercise strengthens the hip muscles to maintain knee stability. While standing, place a small elastic band around your ankles. While keeping the other leg stationary, move one leg sideways until the band is fully stretched. Return the leg to the starting position. Repeat with the other leg. Hold on to a table or chair for balance if you need to. Repeat two sets of 10 per leg.

To do this quadriceps-strengthening exercise, lie or sit with your leg out straight. Tighten the muscle in the front of your thigh as much as you can, pushing the back of your knee flat against the floor. Tightening your muscle will pull your kneecap up toward your thigh and hip. Hold the muscle tight for five seconds. Do 12 repetitions of this exercise, three times a day.

This exercise strengthens the hip muscles in a functional movement pattern while mimicking stair-climbing. Stand on the stair that’s lowest to the ground. While standing sideways, gradually lower the foot that’s closest to the ground off the stair. (Because you are standing sideways on the stair, one foot is closer to the ground, and the other is closer to the next stair.) Bring it back to the stair. Do two sets of 10 for each leg.

York recommends single leg raises, which involve lying on the floor on your back. Your elbows should be directly under your shoulders to support your upper body, and your legs should be out straight. Bend the knee on the side that isn’t injured, so that your foot is flat on the floor. Tighten the thigh muscle of the other leg, and lift the leg straight up from the floor about 6 to 10 inches. Hold the position for five seconds, then release and bring the leg down. Complete three sets of 10 repetitions.

“Work to keep your leg straight while performing this exercise,” York says.

You can also perform this exercise in the supine position (on your stomach) to work the hamstrings and the gluteus along the back of your leg.

Stand with your feet shoulder width apart. Reach your arms straight out in front of you, or gently place them on the tops of your thighs, but don’t put pressure on them; doing so can create a greater challenge for the knees that would be best to avoid. You can also hold onto the back of a chair or the wall for balance.

Keeping your spine straight, slowly lower your hips about 10 inches as though you were going to sit in a chair. Keep your weight in your heels and hold that position for five seconds. Push up from the heels to come to a full standing position. Complete three sets of 10 repetitions.

Also called leg extensions, this exercise helps build up the quadriceps muscles along the front of the thigh. While sitting on a chair with your back straight, tighten your thigh muscles, and straighten at the knee to raise your leg. Squeeze your thigh muscles, and hold that position for five seconds. Relax the foot back to the floor. Be careful not to swing your leg. Complete three sets of 10 repetitions.

Using a recumbent bike is a great way to increase range of motion while minimizing the forces that are placed on the knee joint.

In addition to these specific knee exercises, there are a few other things you can do to prevent or alleviate knee pain, Diaz says. These include:

Generally, getting and staying more active can help support good joint health and keep knee pain at bay. Diaz recommends low-impact exercises, such as cycling, swimming and short walks, which reduce knee stress and can help alleviate pain. Regular stretching of the hip, knee and ankle muscles can also enhance flexibility for daily movement.

Keeping your body weight at an optimal level can help take some pressure off your knees. In fact, every pound of weight you lose is equivalent to taking 4 pounds of pressure off your knees, according to one study. That means, if you lose 5 pounds, you can remove 20 pounds of pressure from your knees.

If your pain is intense, flares up suddenly or lingers and becomes chronic, you should talk to your health care professional about what’s happening.

While physical therapy, rest, ice and over-the-counter pain relievers can all help alleviate pain, you may need surgery, depending on the source of the problem.

It’s common to experience knee pain at some point in your life, whether from injury or age-related conditions, but you don’t have to suffer. A doctor or physical therapist can help you get moving again by providing you with exercise and other ways to relieve the pain and prevent it from coming back.