Knee swelling can be frustrating and painful. This fluid buildup, also known as edema or knee effusion, is often a result of an injury, surgery, or chronic condition like lymphedema.

Knee pain and swelling are sometimes normal.

For example, if you’re recovering from a knee replacement surgery, the swelling in the knee should gradually go down. But for some people, it can linger on for months or even turn into a chronic condition like lymphedema.

So, how do we get rid of knee swelling? I’m a physical therapist and a certified lymphedema therapist (CLT-LANA), and here are my 5 most effective exercises to reduce fluid in the knee, plus other treatments!

Why Is My Knee Swelling?

Your knee is probably swelling because there’s excess fluid that has accumulated in your knee joint. This can happen for many reasons:

• Knee replacement surgery
• Other knee surgeries
• Accidents
• Arthritis
• Leg lymphedema
• Soft tissue injuries
• Other medical conditions

Typically, swollen knees are temporary, and the discomfort and joint pain should reduce as your injury heals. But in some cases, knee swelling can be chronic. For example, rheumatoid arthritis and lymphedema are conditions that may cause chronic knee swelling.

Knee Swelling After Surgery

According to the American College of Rheumatology, approximately 790,000 knee replacement surgeries happen in the US every year. This number is projected to grow to 3.5 million procedures per year by 2030 as our population ages.

Pain and swelling are the most common complaints after a knee replacement. 

During surgery, the doctor cuts the skin, soft tissues, and bones. After knee surgery, your body needs time for the healing process, so it’s common to have more blood flow to the area for a little while.

This is called surgical swelling, and it should last for about 4-6 weeks.

You may notice swelling around the knee, above, below, or even into the lower leg and around the ankle area. It may get worse at the end of the day, especially if you’ve been active.

Learn more about when to worry about swelling after surgery.

Signs That You Have Fluid Buildup in the Knee

How can you tell if you have fluid buildup in your knee? Look out for these signs:

• Visible swelling or puffiness around the knee
• Difficulty bending or straightening your knee fully
• A feeling of tightness or a stiff knee
• Warmth in the knee area
• Pain or discomfort, especially when moving or touching the knee
• A squishy or “water balloon” sensation when pressing on the knee

If you notice these symptoms, it’s a good idea to check in with your medical provider. Even though knee swelling often goes away once the underlying cause (such as an injury) has healed, sometimes it’s a sign that there’s something else going on.

For example, if it’s only your right or left leg that’s swelling, it might be a symptom of a chronic condition called lymphedema.

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5 Physical Therapy Exercises to Reduce Fluid in the Knee

Exercise is one of the best ways to get rid of most knee pain and swelling.

Your muscles act as a natural pump for your circulatory and lymphatic systems. When you’re active, your muscles help push fluid up and out of the affected knee.

After surgery or injury, many people rest and recover (which is important, of course!). But too much inactivity can cause more fluid to pool around the knee. Doing gentle exercises like ankle pumps and leg raises can relieve knee swelling.

Here are the 5 exercises to reduce fluid in the knee that I recommend as a physical therapist:

1. Ankle Pumps

Ankle pumps are a simple but effective exercise to get fluid moving out of your leg and knee.

How to do ankle pumps:

1. Lie down or sit with your leg elevated on a pillow or wedge.
2. Point your toes towards your nose, then push them away from you.
3. Repeat this motion 20-30 times, a few times a day.

This exercise activates the calf muscles, which help pump fluid out of the swollen area.

2. Knee Bends

Knee bends help improve circulation and reduce swelling by gently compressing and releasing the knee joint.

How to do knee bends:

1. Lie on your back with your leg straight.
2. Slowly bend your affected knee, sliding your heel up.
3. Hold for a few seconds, then slowly straighten your leg.
4. Repeat 10-15 times, 2-3 times a day.

If you feel discomfort or pain, stop the exercise (especially when recovering from a knee injury).

3. Leg Raises

Leg raises strengthen the muscles around your knee and help pump fluid out of the area.

How to do leg raises:

1. Lie on your back with your unaffected leg bent and your foot flat on the floor.
2. Keep your affected leg straight and slowly raise it to the height of your other knee.
3. Hold for 5 seconds, then slowly lower your leg.
4. Repeat 10-15 times, 2-3 times a day.

4. Hamstring Stretch

Hamstring stretches help reduce stiffness in the back of your leg and improve circulation around the knee.

How to do a hamstring stretch:

1. Lie on your back with both legs straight.
2. Lift your affected leg up and hold it behind your thigh or calf (whichever feels comfortable).
3. Gently pull your leg toward your chest until you feel a mild stretch in the back of your thigh.
4. Hold for 20-30 seconds, then slowly lower your leg.
5. Repeat 2-3 times, a few times a day.

You should feel a gentle stretch. If you can’t reach your leg comfortably, you can use a towel or strap around your calf to help pull it toward you.

5. Prone Extension Stretch

Prone extension stretches help restore the full range of motion in your knee, which is especially helpful after surgery or injury.

How to do a prone extension stretch:

1. Lie on your stomach with both legs straight.
2. Place a small rolled towel under your ankle on the affected side.
3. Relax your leg and let gravity gently straighten your knee.
4. Hold this position for 5-10 minutes.
5. Repeat 2-3 times a day.

This exercise helps your knee straighten, which can be difficult after swelling or surgery. If you feel too much discomfort, remove the towel and just let your leg rest flat.

👉 Looking for more exercises to help with leg or knee swelling? Start with these step-by-step guides:

Other Ways to Manage Knee Swelling

Vibration Plates

Vibration plates are exercise platforms that create fast vibrations while you stand or sit on them. These vibrations cause your muscles to contract and relax, which helps pump fluid through your lymphatic system.

As a physical therapist, I often recommend vibration plates for knee swelling because they activate the muscles in your legs without putting much stress on your knee joint. If regular exercises feel uncomfortable, you might feel better doing vibration plate exercises.

You can stand on a vibration plate for a few minutes at a time or do gentle exercises like squats or calf raises, if that feels comfortable.

Here are my favorite vibration plate brands + exercise routine:

Compression Therapy

As a certified lymphedema therapist, I often see people with swelling in the knee that develops as a result of chronic conditions like lymphedema or venous insufficiency. Especially in combination with knee surgery or an injured knee, there can be severe swelling in these cases.

Compression therapy is a great way to manage persistent swelling.

Different types of compression garments can be used:

• Compression stockings: Available in knee-high or thigh-high options
• Velcro wraps: These are adjustable and easy to use
• Custom compression garments: For severe cases or unique anatomical needs

With compression garments, it’s very important to buy the correct size that fits properly.

If you get a garment that’s too small or too tight, you’re at risk of getting a tourniquet. This is when the compression stocking digs into the skin too much and can actually make the swelling worse or cause some skin breakdown.

Lymphatic Drainage

Manual lymphatic drainage is a gentle massage technique that helps move fluid out of swollen areas and back into circulation. It uses very light pressure and hand movements that follow the direction of lymph flow.

For knee swelling, a therapist (or you, after learning the technique) would use slow, gentle strokes to encourage fluid to drain from your knee toward your lymph nodes. This helps reduce swelling and can improve how your knee feels and moves.

Take a look at this before and after of a lymphatic drainage massage.

You can learn how to do lymphatic drainage massage at home, but it’s important to learn the right technique. Even though lymphatic drainage massage is rarely dangerous, using too much pressure or massaging in the wrong direction could make swelling worse.

Get started with these guides:

Kinesiology Tape

Kinesiology tape can be a useful tool for managing mild swelling and pain in the knee. It lifts the skin slightly to create a space between the skin and the underlying tissues. This encourages fluid movement and can help reduce swelling.

You can wear kinesiology tape for 3-5 days if there’s no skin irritation.

Icing and Elevation

Elevating your leg and applying ice are two effective ways to reduce swelling. Elevation uses gravity to help drain excess fluid. In turn, icing narrows your blood vessels and reduces blood flow and swelling in the area.

Follow these steps:

1. Lie down and prop your leg up on pillows so that your knee is above your heart.
2. Apply an ice pack to your knee for 15-20 minutes.
3. Repeat this process 3-4 times a day.

You should start seeing your swollen knee improve shortly after.

Walking

Walking is a great low-impact exercise to reduce knee swelling and improve your range of motion.

Start with short distances and gradually go on longer walks as you feel comfortable. Wear supportive shoes with good cushioning and avoid surfaces that put extra stress on your knees. If walking feels uncomfortable, ask your healthcare professional if it’s ok for you to do it.

Could Your Knee Swelling Be Lymphedema?

Lymphedema is a chronic condition that causes fluid to build up in your body. It often affects legs, so you can sometimes mistake it for persistent knee swelling.

If your knee swelling keeps coming back and doesn’t improve with rest, ice, elevation, and time, it might be lymphedema.

Here are some signs that your knee swelling could be lymphedema:

• The swelling is only in one leg or one foot
• It’s been going on for weeks or months without getting better
• Your leg feels heavy or tight
• The swelling is painful
• You’ve had cancer treatment, surgery, or radiation in the past
• Pressing on the swollen area leaves an indent that slowly fills back in

If you think you might have lymphedema, it’s important to see a healthcare provider who can evaluate you and refer you to a certified lymphedema therapist if needed.

Complete Decongestive Therapy (CDT)

If you have lymphedema, you’ll need to do Complete Decongestive Therapy (CDT).

CDT is an intensive treatment program to reduce swelling and improve circulation. You typically work with a certified lymphedema therapist, and there are two phases: an intensive treatment phase and a maintenance phase.

Complete Decongestive Therapy usually involves:

• Manual lymphatic drainage: A massage technique that helps the lymphatic system move extra fluid.
• Compression therapy: Using bandaging or compression garments to prevent fluid from accumulating in the knee.
• Exercise: Physical therapy exercises to activate muscles and knee joints.
• Skin care: Cleaning and moisturizing your skin to prevent infections.

After the initial intensive phase, you typically transition to a maintenance phase, where you continue the treatment at home. 

Learn more about lymphedema self-care.

Signs of Infection and Blood Clots

Some knee swelling is normal, especially after surgery or injury. But certain signs require immediate medical attention:

• Rapid, severe swelling in the knee
• Redness
• Knee pain
• Flu-like symptoms
• Fever or chills

These symptoms could be a sign of an infection or a blood clot, which are serious conditions that need urgent care. If something feels off, it’s better to get in touch with your medical provider as soon as possible instead of waiting it out.

FAQs

Why is the fluid in my knee not going away?

If the fluid in your knee isn’t going away, it usually means that the underlying cause hasn’t been resolved yet. This could mean an injury that’s still healing or a chronic condition like lymphedema or venous insufficiency. Sometimes after knee surgery, swelling can last longer than expected if you’re not moving enough or if there’s scar tissue forming. If your knee swelling has lasted more than a few weeks without improvement, check in with your healthcare provider to figure out what’s causing it.

When should you worry about a swollen knee?

You should worry about a swollen knee if you notice sudden, severe swelling, especially if it’s accompanied by redness, warmth, intense pain, fever, or flu-like symptoms. These could be signs of infection or a blood clot, both of which need immediate medical attention.

You should also be concerned if the swelling is only in one leg and doesn’t improve with rest and elevation, as this could mean that you have a chronic condition called lymphedema.

Is walking good for fluid in the knee?

Yes, walking is generally good for fluid in the knee because it activates your leg muscles, which help pump fluid out of the swollen area. Short and gentle walks can be a great way to keep persistent swelling under control. But if walking causes pain or makes your swelling worse, stop and check with your healthcare provider before continuing.

What is the fastest way to get rid of fluid in the knee?

Some of the fastest ways to reduce fluid in the knee are usually elevating your leg above your heart, applying ice for 15-20 minutes at a time, and doing gentle exercises like ankle pumps and leg raises to activate your muscles. But the swelling will likely come back until you address the underlying cause, such as healing from an injury or going through surgery recovery.

Dealing with Chronic Knee Swelling?

If you’re dealing with chronic knee swelling, it could be a sign of lymphedema. Lymphedema is very common and affects up to 250 million people worldwide.

If you have leg lymphedema, you can find physical therapy exercises and techniques that’ll help you manage swelling in my program, Lower Body Lymphedema Rehab.