Common Causes of Leg Swelling

Medically Reviewed by Jennifer Robinson, MD on January 11, 2023
8 min read

Have you noticed lately that your socks are tight and your pants feel snug? Your legs swell for two main reasons:

  • Fluid buildup (edema): It happens when the tissues or blood vessels in your legs hold more fluid than they should. This can happen if you simply spend a long day on your feet or sit for too long. But it may also be a sign that you’re overweight or don’t get enough exercise, or of more serious medical conditions.
  • Inflammation: It happens when the tissues in your legs get irritated and swollen. It’s a natural response if you break a bone or tear a tendon or ligament, but it also may be a sign of a more serious inflammatory illness, like arthritis.

Several things can lead to extra fluid, or edema, in one leg or both:

Congestive heart failure

This happens when your heart is too weak to pump all the blood your body needs. It leads to fluid buildup, especially in your legs. Other symptoms of congestive heart failure:

  • Shortness of breath or trouble breathing when active or lying down
  • Tiredness

Learn more about heart failure symptoms.

Vein issues

Deep vein thrombosis (DVT) and thrombophlebitis: If you have DVT, it means there's a blood clot in a vein in your leg. It could break off and travel to your lung. When that happens, it's called a pulmonary embolism, and it can be life-threatening.

In thrombophlebitis, also called superficial thrombophlebitis, clots form closer to the surface of the skin and aren't likely to break off.

One of the first symptoms of DVT or thrombophlebitis is one swollen leg (especially the calf), as blood pools in the area. Check with your doctor right away if you have swelling in one leg or any of these other symptoms:

  • Leg pain, tenderness, or cramping
  • Skin that's tinged red or blue
  • Skin that feels warm

Varicose veins and chronic venous insufficiency: You get these conditions when the valves inside your leg veins don't keep the blood flowing up toward your heart. Instead, blood backs up and collects in pools, causing bluish clusters of varicose veins on your skin. Sometimes, they can make your legs swell.

Some other symptoms might include:

  • Pain after sitting or standing for a long time
  • Changes in skin color-- you might see clumps of red or purple veins, or the skin on your lower legs might look brown
  • Dry, irritated, cracked skin
  • Sores
  • Achy legs

Kidney problems

Long-term kidney disease happens when your kidneys don't work the way they should. Instead of filtering water and waste material from your blood, fluid gathers in your body, which causes swelling in your arms and legs.

You may also notice symptoms like these:

  • Fatigue
  • Shortness of breath
  • Nausea
  • Too much thirst
  • Bruising and bleeding

Acute kidney failure -- when your kidneys suddenly stop working -- can also cause swollen legs, ankles, and feet. But it usually happens when you’re hospitalized with other problems. Learn more about acute kidney failure symptoms and causes.


Sometimes, swelling can be an unwelcome side effect of prescription drugs. The medications most likely to cause swollen legs include:

  • Heart medicines called calcium channel blockers:
    • Amlodipine (Norvasc)
    • Nifedipine (Adalat CC, Afeditab CR, Nifediac CC, Nifedical XL, Procardia)
  • Nonsteroidal anti-inflammatory drugs (NSAIDs), like:
    • Aspirin
    • Celecoxib (Celebrex)
    • Ibuprofen
    • Naproxen
  • Certain diabetes drugs, including Actos and Avandia
  • Hormone medications containing estrogen or progesterone
  • Some antidepressants

Call your doctor if you take any of these drugs and get swollen lower limbs. Learn more about common medication side effects.


By the third trimester, your growing baby puts pressure on the veins in your legs. This slows the circulation of your blood and causes fluid to build up. The result: mild swelling.

If you notice these other symptoms as well, let your doctor know because it might mean you have a serious condition called preeclampsia:

  • Severe swelling, especially around your eyes
  • Bad headache
  • Vision changes like blurriness or sensitivity to light

If you have swollen legs and shortness of breath during the last trimester or soon after delivery, talk to your doctor about a condition called peripartum cardiomyopathy, a type of heart failure related to pregnancy. 

Learn more about swelling and other discomforts during pregnancy.

If fluid buildup isn’t to blame for your swollen legs, it could be inflammation. Common causes include:

Arthritis and other joint problems

Several diseases and conditions can make your legs swell:

  • Gout: A sudden, painful attack caused by uric acid crystals in your joints that usually follows drinking heavily or eating rich foods. Learn more about the symptoms of gout.
  • Knee bursitis: Inflammation in a bursa, a fluid-filled sac that acts as a cushion between bone and muscle, skin, or tendon. Learn how to treat knee bursitis.
  • Osteoarthritis: The wear and tear type of arthritis that erodes cartilage. Learn more about osteoarthritis symptoms.
  • Rheumatoid arthritis: A disease where your immune system attacks tissues in your joints. Learn more about rheumatoid arthritis.

Infections, strains, sprains, and broken bones

If you twist your ankle or break a bone, you'll likely get some swelling. It's your body's natural reaction to the injury. It moves fluid and white blood cells into the area and releases chemicals that help you heal.

Some of the most common injuries are:

Achilles tendon rupture: This is your body’s largest tendon. It connects your calf muscles to your heel bone. It’s what helps you walk, run, and jump. If it tears, you might hear a pop then feel a sharp pain in the back of your ankle and lower leg. You probably won’t be able to walk. Learn more about Achilles tendon injuries.

Anterior cruciate ligament (ACL) tear: Your ACL runs diagonally across the front of your knee and holds the bones of your lower leg in place. When it tears, you’ll hear a pop and your knee may give out. It’ll also be painful and swollen. Learn more about ACL injuries.

Cellulitis: This serious infection happens when bacteria like streptococcus and staphylococcus get in through a crack in your skin. It’s most common in your lower leg. Other symptoms include:

  • A red area of skin that gets bigger
  • Tenderness
  • Pain
  • Warmth
  • Fever
  • Red spots
  • Blisters
  • Dimpled skin

Cellulitis can spread through your body quickly. Go to the ER if you have:

  • A fever
  • A red, swollen, tender rash that changes rapidly

See your doctor as soon as you can (the same day is best) if you have:

  • A swollen, red, tender, expanding rash but no fever.

Infection or wound: Anytime you get a cut, scrape, or more serious wound, your body rushes fluid and white blood cells to the area. That causes swelling. If it lasts longer than 2-3 weeks, see a doctor.

If the wound gets infected, you could have more swelling. Swelling is normal for a few days. It should peak around the second day and start to improve. If you have diabetes or another condition that affects your immune system, see your doctor. 

Learn more about the signs of a skin infection.

You can try these home remedies to ease the swelling:

  • Cut back on salty foods.
  • Get exercise every day.
  • On long car rides, switch positions and stop for breaks as often as you can.
  • When you fly, get up from your seat and move around as much as possible.
  • Raise your legs above your heart level for half an hour, several times a day.

But leg swelling can be a sign of something serious. If you also notice other symptoms, especially leg pain, shortness of breath, or extreme fatigue, call your doctor right away.

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Use the R.I.C.E. method

R.I.C.E. is an acronym for a common routine to treat many physical problems, especially painful inflammation in your arms or legs. It’s short for rest, ice, compression, and elevation.

  • Rest. If movement is painful at first, rest your legs and stay off them as much as you can until you’re able to move without pain.
  • Ice. Keep an ice pack on your legs for about 20 minutes every hour over the first 3 days after symptoms start. Avoid using heat, as it may make swelling worse.
  • Compression. Wrap an elastic bandage around your legs or wear compression stockings, which use pressure to keep swelling down.
  • Elevation. Keep your legs raised above the level of your heart for 30 minutes, three or four times per day, so that gravity can help move fluids out and toward the rest of your body.

You might also add a “P” at the beginning of the acronym, for protection (making it P.R.I.C.E.). This is important if infection, injury, or surgery is the cause of your painful swelling. In this case, the first goal is to protect against further damage by staying off your feet as much as possible until your symptoms get better. It might also mean using a brace or wrap to keep your legs from moving as much.

Take over-the-counter medicines 

You can find several kinds of medications at your local pharmacy or grocery store that can help your legs get some relief. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen may help ease swelling and pain from inflammation. Acetaminophen might also fight pain.

Some doctors say magnesium is a good mineral to add to your diet to help with painful swelling. Always check with your doctor before taking any new supplements since some could interfere with medications.

Stay hydrated

It might not seem logical, but drinking more water will actually help get rid of the excess water that causes swelling in your body. On the other hand, when you’re not getting enough water on a regular basis, your body will want to hold more to make up for it. Aim for 8 ounces every 2 hours. Also try to limit the amount of salt and carbohydrates you eat during the day.

Take a salt bath

Soak your legs for 15 to 20 minutes in lukewarm water with Epsom salts, which helps relax muscles and ease swelling. If you don’t have a bathtub, try to find a bucket big enough to fit at least one leg at a time, with the water covering your legs up to your knees.

Try massage

If you can’t visit a massage therapist and don’t have any tools, you can still do massage on your own at home. Rub or stroke your legs upward, in the direction of your heart. Make sure the pressure is firm but not painful. This can help move excess fluid out of that area.

Get moving

Sitting or standing in one place for too long can make painful swelling worse. Get up and stretch as often you can during the day. Focus on extending your knees as well as flexing your ankles to help with blood circulation. This may help pump extra fluid away from your legs and back toward your heart. If you have joint problems, try swimming; this exercise lets your body move without having to bear weight and can also soothe your skin.

These tips will help with leg pain and swelling whenever you have to lie down or stay seated for long periods of time, such as when you’re sleeping, traveling, or working at a desk:

  • Don’t wear tight clothing, especially around your thighs.
  • Wear compression stockings that are approved by your doctor.
  • Take a break to walk around at least once every hour.
  • When you’re sitting or lying down, try to keep your feet up off the floor.
  • Put phone books or bricks under the feet of your bed to lift it, or put a pillow beneath your legs to keep them raised above your heart at night.