Weakness in the legs may happen for a variety of reasons. It may affect one leg or both and may come on suddenly or days or weeks.
Sometimes, weakness in the legs may signal an underlying medical condition that requires treatment.
This article outlines the various causes of weakness in the legs and their associated treatment options. We also provide information on when to see a doctor.
Delayed onset muscle soreness (DOMS) is muscle pain that occurs around 1–2 days after physical activity. The condition usually occurs after one of the following:
- starting a new exercise routine
- changing an existing exercise routine
- increasing the duration or intensity of a regular workout
People who develop DOMS after a leg workout may also experience temporary weakness in the legs.
The following home treatments may help to alleviate the symptoms of DOMS:
- resting and avoiding any activities that lead to DOMS
- applying ice to the affected muscles to reduce pain and swelling
- massaging the affected muscles
- taking over-the-counter (OTC) painkillers
A herniated disk is where a disk in the spine becomes damaged and puts pressure on the spinal cord and nearby nerves. This can cause nerve irritation that leads to:
- weakness in one or both legs
- numbness or tingling in the legs or feet
- shooting pain down one leg
A herniated disk is a common cause of lower back and leg pain. Mild cases are not usually a medical emergency. However, a person should see a doctor to find out the cause and to receive any necessary treatments.
A person should go to the emergency room if they lose bladder or bowel control, or experience other severe symptoms of a herniated disk.
A person who has a herniated disk may find relief with the following home treatments:
- avoiding the activity that causes pain
- applying heat pads or cold packs to the affected area
- taking OTC nonsteroidal anti-inflammatory drugs (NSAIDs)
Research states that about 90% of people will get relief from a herniated disk within 6 weeks. If a person experiences persistent symptoms, their doctor may offer other treatments, such as:
In some cases, tissues may pinch or compress a nerve in the spine. This may cause weakness in the legs.
Causes of spinal compression include:
- scoliosis, which is an abnormal curvature of the spine
- bone growths or bone spurs on the spine
- a broken vertebra
- a tumor on the spine
Besides weakness in the legs, hands, or arms, other potential symptoms of spinal compression include:
- shooting pain in the neck, back, or legs
- pain that spreads from the spine to other parts of the body, such as the arms or legs
- numbness in the feet
- weakness in one foot, resulting in a limp
The treatment for spinal compression depends on the cause and any associated symptoms. Some potential treatment options include:
- steroid injections to reduce swelling
- physical therapy to strengthen the back
- wearing a back brace or cervical collar to support the back
Peripheral neuropathy happens when nerves outside of the brain and spinal cord become damaged. This damage may occur for a variety of reasons, including injury, infection, and disease.
The symptoms of peripheral neuropathy tend to come on slowly over time and may vary between people. Possible signs and symptoms of peripheral neuropathy include:
- muscle weakness in the legs or other parts of the body
- gradual numbness or tingling in the hands, feet, arms, and legs
- sharp, prickling or burning pain in parts of the body
- sensitivity or inability to sense touch
- inability to feel heat or cold
- excessive sweating, or inability to sweat
- changes in blood pressure that cause lightheadedness or fainting
- difficulty controlling the bladder or bowel
- difficulty with walking or coordination
Without treatment, peripheral neuropathy can cause long-term nerve damage. The treatment depends on its underlying cause.
People may also benefit from medications to alleviate nerve pain.
Guillain-Barré syndrome (GBS) is a rare nerve condition that occurs when the immune system attacks part of the body’s nervous system.
The major symptom of GBS is weakness on both sides of the body, such as in both legs or arms. Other symptoms may include:
- sensations of pain or tingling in the feet, legs, back, or hands
- abnormal blood pressure or heart rate
- difficulty walking, or climbing stairs
- difficulty speaking or chewing
- changes in vision or eye muscle control
The symptoms of GBS may appear over several hours, days, or weeks. In rare cases, the condition can be life-threatening. However, up to 70% of people will recover fully with proper medical care, according to the National Institute of Neurological Disorders and Stroke (NINDS).
A person should see a doctor right away if they experience symptoms of GBS.
There is currently no cure for GBS. However, certain treatments are available that may help to:
- reduce the severity of symptoms
- decrease recovery time
- treat complications of GBS
Two key treatments for GBS are:
- Plasma exchange: Plasma exchange removes harmful antibodies from the blood that might attack the nerves, and returns healthy blood to the person.
- Immunoglobulin therapy (IVIg): A person receives intravenous injections of proteins that attack harmful pathogens in the blood, preventing damage to the nerves.
Myasthenia gravis is an autoimmune condition in which a person’s antibodies mistakenly attack and destroy receptors in muscles that receive nerve impulses. This leads to gradual muscle weakness and fatigue.
People who have myasthenia gravis may experience muscle weakness in the following parts of the body:
Usually, a person feels weaker after using their muscles but feels better after periods of rest. The symptoms of weakness tend to come on gradually rather than suddenly. Other symptoms may include:
- drooping of one or both eyelids
- blurred vision, or double vision
- difficulty with swallowing or speaking
- difficulty walking
- difficulty lifting objects
Myasthenia gravis requires medical treatment. A person who experiences symptoms of this condition should see their doctor.
Some potential treatment options for myasthenia gravis include:
- medications that increase muscle strength by preventing the breakdown of the neurotransmitter acetylcholine
- medications that help to reduce the activity of the immune system
The Centers for Disease Control and Prevention (CDC) estimate that ALS affects fewer than 20,000 people in the U.S. However, the exact prevalence is unclear.
The symptoms of ALS appear gradually and can be very different for each person. Some possible symptoms include:
- muscle weakness in the arms or legs
- muscle stiffness
- muscle twitches
- difficulty with speech or swallowing
- tripping, or dropping things
There is currently no cure for ALS and no treatment that will stop the disease from progressing.
However, treatments are available to help manage the symptoms and prevent unnecessary complications. These include drugs, breathing support, and forms of therapy.
A stroke happens when a blood vessel that carries oxygenated blood to the brain becomes blocked or bursts. The brain then starts to lose oxygen and nutrients, leading to a loss of brain cells and brain function.
According to the CDC, stroke affects more than 795,000 people in the U.S. each year. It is the leading cause of long-term disability and the fifth leading cause of death.
Symptoms of a stroke come on suddenly and may differ depending on the part of the brain involved. Some potential signs and symptoms of stroke include:
- weakness in one or both legs
- numbness or weakness in an arm or the face
- slurred speech, or other speech difficulties
- visual disturbances, or loss of vision in one or both eyes
- sudden confusion
- dizziness or loss of balance
- difficulty standing or walking
- severe headache
A stroke is a medical emergency. People who experience stroke should call 911 immediately or have someone take them to the nearest emergency room. Prompt treatment can be life-saving.
The treatment for a stroke depends on whether a person has an ischemic stroke or a hemorrhagic stroke. An ischemic stroke involves a blockage in a blood vessel, whereas a hemorrhagic stroke involves a burst blood vessel.
Some potential treatment options for an ischemic stroke include:
- medications to break up the blood clot
- an emergency surgical procedure to remove the blood clot and restore blood flow to the brain
- medications that help to prevent the formation of further blood clots
People who experience a hemorrhagic stroke may require medications to prevent further strokes. In rare cases, a person may need surgery to repair damaged blood vessels in the brain.
A person who experiences any symptoms of a stroke should call 911 or go to the emergency room right away. Immediate treatment will help to reduce the risk of complications or death.
A person should see a doctor if weakness in the legs is mild and gradually develops over days, weeks, or months. Such symptoms could indicate an underlying health issue that requires treatment.
Weakness in the legs often occurs as a result of overactivity. However, it can sometimes be a sign of an underlying medical condition.
A person who experiences sudden weakness in the legs or some other part of their body should seek emergency medical attention. Such symptoms could signal a stroke or other life-threatening illnesses.
People who experience severe, persistent, or worsening weakness in the legs should book an appointment with their doctor. The doctor will work to determine the cause and provide appropriate treatments.