Certain neuromuscular diseases can cause leg weakness. Toxins such as botulinum toxin (Botox) and certain medications can also cause weakness in the legs.
This article will focus on conditions that cause loss of strength in the leg muscles. It will also discuss treatment options and when to seek medical care for leg weakness.
Sudden leg weakness can be a sign of stroke, a potentially life threatening condition.
Warning signs of stroke
Seek immediate medical care (call 911) for leg weakness that occurs suddenly, particularly if it is felt on one side of the body or occurs with serious symptoms such as:
- arm weakness
- paralysis or inability to move any body part
- loss of balance or coordination
- numbness
- facial drooping
- difficulty speaking or understanding speech
- loss of bladder or bowel control
- blurred vision or double vision
- fainting or change in consciousness
- severe headache
- fever higher than 101°F (38°C)
Transient ischemic attack (TIA)
A TIA may also be referred to as a “mini stroke.” It can have symptoms similar to a stroke but only last for a short time. Symptoms of a TIA
Even though a TIA might appear to go away on its own, it could be an early sign of a larger stroke. Call 911 for any symptoms of a TIA.
Sciatica is a
Other symptoms
In addition to leg weakness, symptoms of sciatica may include:
- lower back pain, typically on one side
- pain or burning sensation in the buttocks
- pricking or pins-and-needles sensation
- leg that feels “heavy”
- reduced range of motion
Learn more about sciatica causes, risk factors, and treatments.
Other conditions affecting the spinal cord, backbone (vertebrae), or nerves exiting the spinal cord can all cause leg weakness. These conditions include:
- spinal stenosis
- herniated disc
- arthritis affecting the spine
- spinal cord abscess or tumor
- trauma or injury to the spinal column
- degenerative disc disease
Other symptoms
Along with weakness in the legs, other symptoms that may indicate a spine condition include:
- pain in the back that may radiate to other areas
- burning sensation
- numbness
- tingling or pins-and-needles sensation
- back pain that occurs with a fever higher than 100.4°F (38°C)
- back pain that occurs during sleep
- stiffness upon waking
- pain that gets worse when lying down
If you experience leg weakness along with any of these symptoms, contact your doctor right away for an evaluation. It
Neuromuscular diseases can decrease function in muscles and nerves, including those in the legs.
Neuromuscular conditions that can have leg weakness as a symptom include:
- amyotrophic lateral sclerosis (ALS)
- multiple sclerosis (MS)
- muscular dystrophy
- myasthenia gravis
- cerebral palsy
- fibromyalgia
- Guillain-Barré syndrome
- spinal muscular atrophy (SMA)
SMA primarily affects infants and young children. According to the Muscular Dystrophy Association (MDA), an early symptom of SMA type 2 is muscle weakness in the legs. This typically presents in children ages 3 to 15 months. If your child shows any signs of muscle weakness, contact your pediatrician right away.
Other symptoms
Neuromuscular diseases can cause other symptoms along with leg weakness, including:
- muscle weakness in the:
- neck
- arms
- hands
- fingers
- muscle twitches and cramps
- muscle stiffness
- vision changes
- lack of facial muscle control
- shortness of breath
- difficulty swallowing
- trouble with speech
- paralysis
Certain treatments and medications may cause muscle weakness, including:
- botulinum toxin (Botox)
- statins
- corticosteroids
Other symptoms
Other symptoms and side effects due to medications or exposure to toxins include:
Treatment for leg weakness will focus on addressing the underlying cause of the condition.
Stroke
Stroke requires emergency treatment as soon as symptoms appear. Remember to think F.A.S.T.:
- facial drooping
- arm weakness
- slurred speech
- time to call 911
Recovery after a stroke may involve a team of care professionals to help address a variety of needs.
Learn what to expect during recovery after a stroke.
Sciatica
Many cases of sciatica
If symptoms of sciatica persist or worsen, your doctor may recommend medical therapies including:
- muscle relaxants
- prescription pain relievers
- oral corticosteroids
- corticosteroid injections to the affected area
- physical therapy
If a structural issue in the spine is causing your sciatica, your doctor may discuss surgical treatment options.
Spine conditions
Similar to sciatica, initial treatment for many spine conditions focuses on non-invasive measures, including:
- physical therapy
- OTC pain relievers, such as nonsteroidal anti-inflammatory drugs (NSAIDs)
- prescription pain relievers
- muscle relaxants
Other treatments for spine conditions may include:
- steroid injections to reduce inflammation
- antibiotics to treat an infection or abscess on the spine
- chemotherapy or radiation to treat tumors on the spine
In severe cases, surgery may be necessary to treat the underlying cause of a spine condition. This may include laminectomy or discectomy to address compression of the nerves.
Neuromuscular disease
Treatment for neuromuscular disease can vary widely depending on the type. Your doctor will assess your specific condition and suggest treatment options that may be best for you.
According to the MDA, possible treatments for neuromuscular disease can include:
- medications, including corticosteroids
- speech therapy
- physical therapy
- breathing assistance
- assistive devices such as standing frames, braces, and wheelchairs
You may also be able to access new treatment options by participating in clinical trials. Talk with your doctor about your eligibility for clinical trials near you.
Medications
Leg weakness may be a side effect of certain medications. If you suspect medication may be causing your leg weakness, contact your doctor. They can suggest alternative treatments that may have less challenging side effects.
The following frequently asked questions have been reviewed by Meredith Goodwin, M.D.
Does COVID-19 cause weakness in the legs?
COVID-19 can cause weakness in the legs. An early 2022 analysis found that musculoskeletal symptoms occurred in people with mild to moderate COVID-19. Symptoms of muscle weakness can also persist in cases of long COVID, making it difficult for some to maintain daily activities.
Can a deficiency cause weakness in the legs?
A thiamine (vitamin B1) deficiency can cause a condition known as dry beriberi, which affects the central nervous system. Symptoms
Can heart problems cause weakness in the legs?
Yes. Heart failure makes it more difficult for blood to reach your legs and feet. This
Leg weakness can result from sciatica, spine conditions, neuromuscular disease, and certain medications. Sudden leg weakness may be a sign of stroke. Call 911 for any sudden muscle weakness, particularly if it occurs with facial drooping, severe headache, or slurred speech.
Treatment for leg weakness varies depending on the underlying cause. Your doctor can provide you with an accurate diagnosis and discuss treatment options that are right for you.
