Read below about swelling in one lower leg, including causes, treatment options and remedies. Or get a personalized analysis of your swelling in one lower leg from our A.I. health assistant. At Buoy, we build tools that help you know what’s wrong right now and how to get the right care.

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Swelling in One Lower Leg Symptoms

Swelling, also called edema, is the result of fluid buildup that gets trapped in your body's tissues. Buildup can occur when there is obstruction and fluid cannot properly flow and/or drain. However, fluid buildup can also occur when an area of the body becomes inflamed, injured or damaged. The small blood vessels in the body begin to leak fluid. Moreover, the body can bring in white blood cells to repair the damage, and more fluid follows. Depending on the cause, the swelling can be generalized and occur throughout the body, or localized and only affect a specific part of the body.

The legs are gravity-dependent. Swelling localized to one leg is often obvious and easy to identify. One leg will appear larger than the other and may be accompanied by the following symptoms as well:

Swelling in only one leg and not the other can be a sign of a serious underlying condition that requires prompt attention. If you notice any of these symptoms, make an appointment with your physician as soon as possible in order to receive appropriate care.

Swelling in One Lower Leg Causes Overview

Causes of swelling in one lower leg can vary, all related in some way to obstruction. Other causes include those that are systemic, inflammatory, and environmental.


As stated above, fluid buildup can occur in the case of obstruction. Obstructive causes of swelling in one lower leg are often related to clotting of the blood. When a blood clot forms in the deep veins of the lower leg (deep vein thrombosis or DVT), it obstructs blood flow and can result in leg swelling and pain [4]. There are different categories of how blood clots can form including:

  • Hematologic: Bleeding disorders and medical conditions such as cancer that affect the way different components of the blood function can result in blood clots.
  • Immobility: When the leg is immobile for long periods of time, such as after surgery or traumatic injury that requires casting, the muscles do not contract normally to help blood circulate; thus, blood flow is disrupted and blood clots can form.

In the case of fluid leakage, there are three general mechanisms that can occur that result in fluid buildup in the surrounding tissues of the leg:

  • Excessive force or pressure inside the blood vessels
  • A force external to the blood vessel that can cause fluid to be drawn out
  • Damage or destruction to the blood vessel wall leading to fluid loss

The exact causes behind these mechanisms can be broad, ranging from benign to life-threatening, so it is important to make an appointment with your physician in order to get appropriate care.


Systemic-related causes of lower leg swelling may include those listed below.

  • Circulatory: Problems with the heart and its ability to pump effectively will cause blood to back up in the lower body. This causes excessive pressure in the blood vessels and leads to damage and further leakage of fluid into the body's tissue.Furthermore, if the veins of the circulatory system are weakened or damaged, the swelling will occur in a similar manner. This more commonly causes swelling in both legs (bilateral).
  • Lymphatic: The lymphatic system is the body's natural way of clearing excess fluid from tissues.It is composed of multiple nodes and vessels, that when damaged, can cause swelling all over the body, especially in the lower leg.
  • Kidney: The kidney is a potent regulator of bodily fluid because it is responsible for filtering and clearing the blood. Without the kidney, filtrate such as proteins, electrolytes, and toxins can remain in the blood and act as forces that draw fluid out. In most cases, kidney problems result in swelling of both legs and usually does not affect only one leg.


Inflammatory causes for swelling in one lower leg may include:

  • Arthritis: Arthritis is a general term for multiple conditions that cause painful inflammation and stiffness of the bones and joints. Arthritic processes that affect the knees and ankles can cause irritation that often leads to injury. Furthermore, arthritis in the joints of the lower extremitiespredisposes people to inactivity, making swelling even more likely.
  • Infection: Both superficial infections of the skin and deep tissueinfections of the lower leg can result in swelling. One type of deep tissue infection, called necrotizing fasciitis, can spread quickly and destroy tissue, resulting in a life-threatening illness that requires immediate care [5].


Environmental causes can range from lifestyle habits to certain exposures listed below.

  • Smoking: Smoking can affect blood clotting and circulation, increasing the risk of deep vein thrombosis [4].
  • Medication: Swelling in one lower leg can be a side effect of many medications that treat common conditions such as high blood pressure, diabetes, and menopause. However, this usually causes swelling in both legs rather than just one.
  • Diet: Diets high in sodium can cause an overload of the body's filtering mechanisms. The extra salt in the blood will cause fluid to be drawn out from the vessels, causing swelling. Furthermore, obesity can increase the pressure in the veins of the lower leg causing leakage and fluid buildup.

A.I. Health Assistant Causes for Swelling in One Lower Leg

The list below shows results from the use of our A.I. Health Assistant by Buoy users who experienced swelling in one lower leg. This list does not constitute medical advice.

  1. 1.Deep Vein Thrombosis

    Deep vein thrombosis (DVT) is a blood clot that forms in a vein deep in the body. Most deep vein clots occur in the lower leg or thigh.

    Curable with medication or surgery but may recur.

    Top Symptoms:
    fever, thigh pain, upper leg swelling, calf pain, butt pain
    Hospital emergency room
  2. 2.Ankle Sprain

    Ankle ligaments, which connect bones to one another, stabilize the ankle joint. A sprain is an injury to the ligaments caused by a twisting motion of the joint.

    An uncomplicated ankle sprain should improve in 3-6 weeks.

    Top Symptoms:
    pain in one ankle, ankle pain from an injury, swollen ankle, bruised ankle, ankle twisting
    Symptoms that always occur with ankle sprain:
    pain in one ankle, ankle pain from an injury
    Phone call or in-person visit
  3. 3.Shin Bruise

    A bruise is the damage of the blood vessels that return blood to the heart (the capillaries and veins), which causes pooling of the blood. This explains the blue/purple color of most bruises. Bruises of the shin are common given the location of the shin.

    Bruises will begin to heal over the course of a week

    Top Symptoms:
    shin pain from an injury, shin injury, pain in one shin, shin swelling, shin bruise
    Symptoms that always occur with shin bruise:
    shin injury, shin pain from an injury
  4. 4.Compartment Syndrome

    Compartment syndrome is a serious condition that involves increased pressure in a muscle compartment. It can lead to muscle and nerve damage and problems with blood flow.

    Prognosis is highly variable after surgery and depends on how rapidly you are treated.

    Top Symptoms:
    arm numbness, hand numbness, foot numbness, pain in one leg, thigh numbness
    Hospital emergency room
  5. 5.Jones Fracture (Broken Foot)

    A Jones Fracture is a fracture of a bone on the outside of the foot (called the fifth metatarsal). A Jones fracture can be either a stress fracture (a tiny hairline break that develops with time), or a sudden break due to trauma. This can result in pain, swelling, and tenderness on the outside of the foot.

    6-8 weeks healing time with cast or splint.

    Top Symptoms:
    difficulty walking, constant foot pain, pain in one foot, foot bruise, foot injury
    Symptoms that always occur with jones fracture (broken foot):
    foot pain from an injury, pain when touching the foot, constant foot pain, pain in the front half of the foot, pain in the outside of the foot
    In-person visit

    Swelling in One Lower Leg Checker

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  6. 6.Calcaneus Fracture

    The calcaneus (heel bone) can be fractured during high-energy collision, such as a fall from height or a motor vehicle crash. Heel bone fractures are often severe, and may result in long-term problems.

    6-8 weeks for the bone to completely heal (for an uncomplicated fracture).

    Top Symptoms:
    swollen ankle, swelling of both feet, severe foot pain, pain in both feet, swelling of one foot
    Symptoms that always occur with calcaneus fracture:
    inability to bear weight immediately after injury, foot pain from an injury, severe foot pain
    Hospital emergency room
  7. 7.Fracture of the Talus

    A talus fracture is a break in one of the bones in the ankle called the "talus." This type of injury oftens occurs during a high-energy event, such as a car accident or fall.

    Recovery may take up to 3 months.

    Ultra rare
    Top Symptoms:
    pain in one foot, swollen ankle, severe foot pain, pain in one ankle, ankle pain from an injury
    Symptoms that always occur with fracture of the talus:
    pain in one ankle, ankle pain from an injury
    Hospital emergency room
  8. 8.Stress Fracture of the Foot (Marching Fracture)

    A "March" stress fracture of the foot is named because it's sometimes linked to soldiers marching for a long time. This foot fracture happens because of prolonged stress or weight-bearing.

    6-12 weeks with treatment

    Top Symptoms:
    constant foot pain, foot pain from overuse, pain in one foot, pain when touching the foot, pain in the top of the foot
    Symptoms that always occur with stress fracture of the foot (marching fracture):
    foot pain from overuse, constant foot pain
    Primary care doctor
  9. 9.Repetitive Strain Injury of the Calf

    Repetitive strain injury of the calf is caused by consistent repetitive use.

    Duplicate: Resolves with rest

    Top Symptoms:
    lower leg numbness, calf pain from overuse
    Symptoms that always occur with repetitive strain injury of the calf:
    calf pain from overuse
    Symptoms that never occur with repetitive strain injury of the calf:
    recent calf injury, severe calf pain
  10. 10.Calf Strain

    A strain, commonly called a "pulled muscle," is when a muscle becomes overstretched, and microscopic tears occur. A calf strain happens when one of the muscles on the back of the lower leg is pulled.

    With proper medical attention, this condition should completely resolve.

    Top Symptoms:
    pain in one calf, moderate calf pain, calf pain, sports injury, soccer injury
    Symptoms that always occur with calf strain:
    pain in one calf

Swelling in One Lower Leg Treatments and Relief

Treatment for obstructive causes of swelling in one lower leg involves prevention of the formation of blood clots. There are several medications that work to thin the blood, break up clots, and filter clots that can break off and travel — keeping them away from the lungs.

Medical treatments

Systemic causes of calf swelling are often treated with medication. Your physician may suggest:

  • Diuretics: These medications,also known as "water pills," increase the water and salt your body excretes in the urine. This strategy helps reduce the fluid trapped in the body and your calves.
  • Anti-inflammatory medications: Your physician may prescribe this type of medication to combat arthritic processes that are causing swelling.

At-home treatments

Fortunately, swelling in the calves can be mitigated by many strategies and remedies you can perform at home:

  • Activity: Moving your legs and staying active can help pump any excess fluid pooling in the legs back toward your heart. Talk to your physician about exercises you can do at home in order to keep moving.
  • Elevation: Place your legs above the level of your heart as much as possible. Elevating the legs during sleep can help significantly with calf swelling.
  • Compression: Your physician may prescribe compression stockings for your legs. These garments keep pressure on your limbs to prevent fluid from collecting in the tissue. See this photo for an example of compression stockings and how they work.
  • Protection: Keep your swollen calves clean and free from injury. Dry, cracked skin is more prone to scrapes, cuts, and infection.
  • Dietary changes: Reducing salt intake, losing weight and quitting smoking can be an important step in reducing your swelling.

Seek immediate medical attention in the emergency room or call 911 for the following

If you experience the items below, this can signify that a clot causing a deep vein thrombosis that has traveled to the lungs in a condition called a pulmonary embolism (PE) [4]:

A pulmonary embolism is a life-threatening emergency that requires immediate attention.

FAQs About Swelling in One Lower Leg

Here are some frequently asked questions about swelling in one lower leg.

Why is the swelling in only one leg?

The swelling is localized to one leg due to obstruction of a deep vein in the leg or because of an infection or other inflammatory condition specifically affecting that extremity.

What tests are usually performed for swelling in one lower leg?

One test your physician may perform is an ultrasound of the affected leg. An ultrasound is a device that sends sound waves through the tissues of the leg and converts the sound waves into an image on a screen. Your physician will be able to visualize a blood clot if it is present.

Can a clotting disorder be inherited?

Yes, clotting disorders can be inherited. Be suspicious of an inherited clotting disorder if you and other members of your immediate family have experienced blood clots or complications of blood clots such as pulmonary embolism or multiple miscarriages.

Can I travel with swelling in one lower leg?

It is not advisable to travel with swelling in one lower leg. Traveling, especially for a long flight or drive, can cause increased disruption of blood flow in the lower leg. The muscles contract less and can further exacerbate a possible clot in the leg that is causing the swelling.

What can I do to prevent immobility in my lower leg on long flights or drives?

Moving as much as possible during a flight can help reduce periods of prolonged immobility. For example, getting up to go to the bathroom or walk up and down every two hours can go a long way in keeping the body active. If you cannot get up, perform seated exercises such as ankle circles, leg raises or foot/calf pumps in order to prevent immobility. Avoid placing hand luggage in places that restrict movement of the legs and wear loose, comfortable clothing.

Questions Your Doctor May Ask About Swelling in One Lower Leg

  • Q.Have you ever been diagnosed with diabetes?
  • Q.Are you having any difficulty walking?
  • Q.What is your body mass?
  • Q.Do you have high blood pressure?

If you've answered yes to one or more of these questions, try our swelling in one lower leg symptom checker to find out more.

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Swelling in One Lower Leg Symptom Checker Statistics

  • People who have experienced swelling in one lower leg have also experienced:

    • 19% Shin Pain
    • 7% Pain in One Shin
    • 5% Moderate Shin Pain
  • People who have experienced swelling in one lower leg had symptoms persist for:

    • 29% Over a Month
    • 28% Less Than a Week
    • 22% Less Than a Day
  • People who have experienced swelling in one lower leg were most often matched with:

    • 66% Deep Vein Thrombosis
    • 22% Ankle Sprain
    • 11% Shin Bruise
  • Source: Aggregated and anonymized results from visits to the Buoy AI health assistant (check it out by clicking on “Take Quiz”).

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  1. Sloane PD, Baldwin R, Montgomery R, Hargett F, Hartzema A. Left-Sided Leg Edema of the Elderly: A Common Variant of the Iliac Compression Syndrome. Journal of the American Board of Family Medicine. 1993;6(1):1-4. JABFP Link
  2. What You Should Know About Swelling in Your Legs. Cleveland Clinic. Published July 13, 2015. Cleveland Clinic Link
  3. Leg Swelling. Mayo Clinic. Published January 11, 2018. Mayo Clinic Link
  4. Deep Vein Thrombosis (DVT). Mayo Clinic. Published March 6, 2018. Mayo Clinic Link
  5. Group A Streptococcal (GAS) Disease. Centers for Disease Control and Prevention. Updated October 18, 2018. CDC Link
  6. Immobility, Circulatory Problems and Deep Vein Thrombosis (DVT). World Health Organization. WHO Link