Knee swelling can arise from any part composing the joint, such as synovial membrane, ligaments, bursae. Besides, blood, pus and other fluid accumulating in the knee can lead to swollen knees. A swollen knee is usually painful, but that's not always the case, especially when the swelling is due to knee effusion. Therefore, you may not require any treatment for your swollen knee, but you have to see a doctor and figure out a treatment plan for conditions like septic arthritis. Consult your healthcare provider to identify the exact cause of swollen knees, if necessary.

What Causes Swollen Knee?

A swollen knee will probably cause deep, aching pain with stiffness. The joint may feel warm to touch. It is important to understand that there will always be an underlying cause of your swollen knee.

1. Strain or Injury

Strain or injury to the knee is the most common causes of swollen knee.

• If you've been involved in strenuous physical activity and put excessive pressure on your knee joint, you make strain and make your knee swollen. Besides, doing an exercise without stretching or warming up may lead to straining.
• Any injury to cartilage surrounding the bones of your knee joint may produce swelling in the knee. For example, the menisci which are rubbery pads of tissues located at the knee joint may wear out due to age and cause severe pain in elderly people. Sudden twist of the knee joint may also tear these shock absorbers and result in swelling.

2. Osteoarthritis

Osteoarthritis is one of the leading causes of knee pain. It damages the articular cartilage and causes mild swelling of the tissues that cover the joints. Sometimes, it leads to fluid-filled swelling that can be quite painful – the condition is known as a Baker's cyst.

3. Torn Tendon

An injury of the tendon that connects your shinbone and kneecap together can lead to inflammation. The condition is sometimes referred to as "jumper's knee" because it is usually the outcome of being involved in jumping activities, such as volleyball or basketball. A torn tendon will cause swelling and the affected area will be red and warm to touch.

4. Gout or Pseudogout

Gout or pseudogout are types of arthritis and may be the reason behind your knee swelling. If you have any of these conditions, you may notice your knee joint to be a bit red and hot to touch. Gout is caused by the excessive production of uric acid, a waste product your body produces during the process of metabolism. Sometimes, your kidneys cannot excrete uric acid properly and it turns into crystals that pile up in the joints, causing pain, inflammation and swelling. If it is pseudogout, the crystals deposited in your joints are usually made up of calcium, not uric acid.

5. Septic Arthritis

This serious condition develops when bacteria or other microorganisms enter the blood stream and affect a joint. Sometimes, a joint gets infected with a microorganism during a surgery. It usually affects the knee and hip, and causes pain, swelling and fever.

6. Other Causes

There can be some other less common causes of swollen knee. For instance:

• Osgood-Schlatter's Disease: The disease causes tenderness and swelling over the bony bump near your kneecap. It usually affects teenagers who overuse their hamstrings or thigh muscles when playing certain sports.
• Housemaid's Knee: If you kneel for an extended period, you may experience fluid buildup over the knee joint, which is called bursitis or "housemaid's knee". The condition usually affects sports players or people who are in jobs that require kneeling.
• Anterior Knee Pain Syndrome: When you experience pain at the front of your knee, around the kneecap, this may be due to a condition called 'anterior knee pain syndrome'. What causes this condition is not clear, but climbing stairs or sitting for prolonged periods may lead to this syndrome.

How to Deal With Swollen Knee

You can try a number of remedies and treatment options to reduce swelling and alleviate pain in the knee.

1. Get Enough Rest

Taking a break from your regular activities will reduce repetitive stress on your knee, alleviate pain and prevent further damage. Taking a couple of days off is usually enough to recover from a minor injury. You may need more rest to recover from severe damage.

2. Try Cold Compress

Ice can work wonders to reduce pain and swelling. You can use a bag of frozen peas and place it over your knee for 15 minutes or so. You can also wrap ice cubes in a thin, small towel for your ice therapy. Don't let your icepack sit on your knee for more than 20 minutes or it may damage your nerves and skin.

3. Use Compression

Using compression will help prevent fluid accumulation in damaged knee tissues. You can even use a lightweight, self-adhesive and breathable compression bandage, which helps maintain stability. Make sure it's tight enough to support proper knee alignment yet loose enough to allow for good blood circulation.

4. Elevate the Swollen Knee

Elevating the knee by placing a pillow under your leg will help reduce swelling. You may also consider sitting in a recliner to make your swollen knee feel better. Just be sure to elevate it higher than the level of your heart.

5. Take OTC Medications

Using over-the-counter medications such as ibuprofen, naproxen and acetaminophen may help ease your knee pain and eliminate swelling. Some creams that contain a numbing agent may provide instant pain relief. Capsaicin and lidocaine are 2 common numbing agents found in some creams.

When to See the Doctor

It is important to see your general physician if:

• You find it hard to put weight on your swollen knee;
• You have severe pain even when your leg is at rest;
• Your knee clicks painfully or locks while walking;
• Your swollen knee keeps giving away and looks deformed;
• You have redness, fever or warmth around the swollen knee;
• You feel swelling, pain, tingling or numbness in your calf area;
• You feel pain even after 3 days of treatments at home.