Leg weakness can be caused by a variety of medical conditions, some of which are serious. Here are some of the possible causes of leg weakness:

1. Stroke: Sudden leg weakness could be a sign of a stroke, which is a medical emergency that requires immediate attention.

2. Guillain-Barré syndrome: This is a rare autoimmune disorder that can cause sudden leg weakness and other symptoms.

3. Multiple sclerosis: This is a chronic autoimmune disorder that can cause sudden leg weakness and other symptoms.

4. Pinched nerve: A pinched nerve in the back can cause leg weakness and other symptoms.

5. Slipped disc: A slipped disc in the back can cause leg weakness and other symptoms.

6. Cauda equina syndrome: This is a rare but serious condition that can cause sudden leg weakness and other symptoms. It requires immediate medical attention.

7. Amyotrophic lateral sclerosis (ALS): This is a progressive neurodegenerative disease that can cause leg weakness and other symptoms.

8. Inflammatory conditions: Inflammatory conditions such as myositis or vasculitis can cause leg weakness and other symptoms.

9. Bacterial or viral infections: Certain bacterial or viral infections can cause leg weakness and other symptoms.

10. Muscle disorders: Muscle disorders such as muscular dystrophy or myasthenia gravis can cause leg weakness and other symptoms.

11. Medication side effects: Some medications can cause leg weakness as a side effect.

12. Spinal conditions and injuries: Spinal conditions and injuries such as spinal stenosis or herniated disc can cause leg weakness and other symptoms.

13. Autoimmune diseases: Autoimmune diseases such as lupus or rheumatoid arthritis can cause leg weakness and other symptoms.

14. Systemic diseases: Systemic diseases such as diabetes or kidney disease can cause leg weakness and other symptoms.

15. Metastatic tumor: A metastatic tumor in the spine can cause leg weakness and other symptoms.

It is important to seek medical attention to determine the underlying cause and receive appropriate treatment. Sudden leg weakness could be a sign of a medical emergency and requires immediate attention[[1]](https://www.h...