Weakness in Legs: 10 Causes & What to Do

Leg weakness is generally not a sign of a serious problem, however it can occur for many reasons, like intense physical activity or poor circulation. 

In some cases, weakness in the legs that persists and does not resolve on its own may be a sign of a more serious condition, like peripheral neuropathy or even a stroke. More serious conditions, will often present with other symptoms in addition to the leg weakness, like dizziness, numbness or general malaise.  

These symptoms should be assessed by a doctor if the weakness persists for a long time, if it worsens over time, or if it interferes with activities of daily living. Once a cause is identified, appropriate treatment can be started. 

Causes of leg weakness

Some conditions that are associated with weakness in the legs include: 

1. Intense physical activity

One of the most common causes of leg weakness is exercise. It can especially be felt in people who do not exercise on a regular basis. Weakness is often experienced right after working out, but tends to improve within a few minutes. 

In the following days, it is possible to experience weakness again. You may notice muscle pain, which is a sign of muscle wear and tear. This usually resolves on its own after 2 to 3 days. 

What to do: In most cases, you are advised to rest and massage the affected leg muscles. This will help relieve discomfort and speed-up recovery. Intense weakness and pain should be assessed by a doctor, who may prescribe an anti-inflammatory. 

2. Poor circulation

Another relatively common condition that can cause leg weakness is poor circulation. This tends to occur in people over the age of 50, or in people who spend a lot of time standing. Read about what can cause poor circulation in the legs.

In addition to weakness in the legs, poor circulation can also lead to other symptoms like cold feet, leg and feet swelling, dry skin and varicose veins. 

What to do: One way to improve leg circulation is to use compression stockings during the day, especially if you know you will be standing for a long time. You should elevate your legs at the end of your day and engage in regular physical activity, like walks. Learn more about how to improve circulation.

3. Peripheral neuropathy

Peripheral neuropathy is characterized by serious damage in the peripheral nerves. These nerves are responsible for transmitting information between the brain and the rest of the body. Damage can cause symptoms like weakness in the arms and legs, tingling and persistent pain. 

Generally, this disease is a consequence of uncontrolled diabetes, leading to diabetic neuropathy, but it can also occur with toxic substance exposure or infections. 

What to do: Treatment consists of tackling the underlying cause of the nerve damage. In some cases, a strict medication routine may be necessary to manage symptoms and improve quality of life. 

4. Herniated disc

A herniated disc is characterized by an intervertebral disc that is bulging out of its space. It can cause symptoms like leg weakness, back pain that radiates to the glutes or legs, difficulty moving, numbness, burning or tingling in the back, glutes or legs. 

What to do: Treatment may involve the use of medication, physiotherapy or even surgery, depending on severity. 

5. Stroke

A stroke is characterized by a sudden interruption in blood flow to the brain. It can lead to weakness in the extremities, paralysis on one side of the body, fainting, dizziness and headache (depending on the part of the brain affected). 

Read more about the symptoms of a stroke and how to recognize one.

What to do: This condition is life-threatening and should be treated urgently. If left untreated, it can cause complications like difficulty talking or moving. To prevent a stroke, patients are encouraged to eat a healthy, balanced diet, exercise regularly and manage or prevent conditions like high blood pressure, cholesterol, high triglycerides and diabetes. 

6. Guillain-Barré syndrome

Guillain-Barré syndrome is a serious autoimmune disorder characterized by the immune system attacking the body’s own nerve cells. It can cause nerve inflammation that leads to extremity weakness and muscular paralysis, which can be life-threatening. 

What to do: Treatment is provided in a hospital setting and may involve a technique called plasmapheresis. This treatment consists of removal of blood from the body to filter out toxic substances that are causing the illness. The blood is then returned to the body. The second part of treatment consists of a high-dose injection of immunoglobulins to destroy antibodies that are causing nerve damage and inflammation.

7. Multiple sclerosis

Multiple sclerosis is a chronic auto-immune disease in which the immune system attacks the body, leading to breakdown of the myelin sheath. The myelin sheath lines each nerve cells, and interruptions in this lining can compromise proper nervous cell function.

Some symptoms associated with this condition are arm or leg weakness, difficulty walking, difficulty coordinating movements, incontinence, memory loss, difficulty concentrating and vision problems. 

What to do: Treatment for multiple sclerosis consists of the use of medication and physiotherapy to manage specific symptoms. Treatment approaches for multiple sclerosis may differ from person to person. 

Other conditions that can also cause leg weakness include Parkinson’s, myasthenia gravid or spine injuries. 

8. Cauda equina syndrome

Cauda equina syndrome is a condition that causes compression of the nerves in the spinal canal, specifically the nerves that control the function of the bladder, intestines, sexual organs and lower limbs. It is characterized by symptoms such as decreased sensitivity in the muscles, genitals and surrounding areas, as well as weakness. in the legs.

This syndrome can occur as a result of a herniated lumbar disc, infections, fractures or tumors.

What to do: Cauda equina syndrome should be treated with emergency surgery, as complications can emerge if left untreated.

9. Transverse myelitis

Transverse myelitis is an inflammation of the spinal cord caused by an autoimmune abnormality or a viral or bacterial infection. It can cause the appearance of symptoms like muscle paralysis, back pain, muscle weakness and decreased sensitivity, in addition to weakness and paralysis of the legs and/or arms.

What to do: treatment for transverse myelitis varies greatly depends on each case, but it usually involves the use of medication to prevent possible infections, reduce spinal cord swelling and relieve symptoms. Treatment is aimed at improving quality of life. 

10. Lyme disease

Lyme disease is a disease caused by tick bites. It is characterized by symptoms such as skin lesions and redness, tiredness, pain and muscle weakness, including in the legs, as well as joint pain, headache, fever and chills, for example.

What to do: Lyme disease is treated with antibiotics such as Doxycycline.