What is Leg Weakness?
Leg weakness is a feeling of weakness in either one or both the legs. The weakness can occur in the whole body along with the legs or can be felt in the legs only. A person develops true weakness when there is loss of strength in the muscles. However, many individuals think that they have muscle weakness when they are feeling tired or weak, but this is not a case of true loss of muscle function. If a person experiences sudden onset of muscle weakness, then it can be an indication of a stroke, which can be a potentially fatal condition where a part of the brain gets deprived of oxygen. So, in such cases, it is imperative that prompt medical attention is sought, especially if the weakness is also felt along one side of the body or if other symptoms accompany the leg weakness, such as double vision or blurred vision, changes in vision or loss of vision, numbness; inability to move a body part or paralysis; high fever; severe headache; loss of bowel or bladder control; change in level of consciousness or fainting; or lethargy.
There are many causes or conditions, which cause leg weakness with true loss of strength in the muscles of the legs. Sciatica is the most common cause for leg weakness. Sciatica then again has many causes. Other than weakness in leg or arm, other sciatica symptoms include burning, tingling and pain. Other than this, spinal cord diseases which cause compression or pinching of the nerves can also cause leg weakness.
Treatment of the leg weakness depends on the cause of leg weakness. So, it is important to diagnose the cause of the leg weakness and start appropriate treatment immediately.
Causes of Leg Weakness
There are many causes for leg weakness which include injury, toxins, neuromuscular diseases or life-threatening conditions, such as stroke. Some of the causes are given below and are grouped according to the part of the body affected and they comprise of:
Leg Weakness Caused By Spinal Problems
Medical conditions, which affect the spinal cord, vertebrae and the nerves can cause leg weakness along with other symptoms, such as burning, pain, tingling or numbness sensation along the path of the affected nerve. Some of the spinal problems that can cause leg weakness include:
- Arthritis of the spine.
- Injury to the spinal cord.
- Abscess or tumor in the spinal cord.
- Herniated disc.
- Degenerative disc disease of the spine (spondylosis).
- Spinal stenosis (narrowing of the spinal canal, creating pressure on the spinal cord or nerves).
Leg Weakness Caused By Trauma
Injury or trauma to the muscles, bones or joints can also cause leg weakness and some of these injuries include:
- Bone fractures.
- Sprains and strains of the muscles and ligaments.
Leg Weakness Caused By Neuromuscular Conditions
Different types of conditions, which affect the nerves or muscles can also cause leg weakness and these conditions are:
- Sciatica, which is a nerve pain caused from irritation to the sciatic nerve. This causes pain from the low back to the leg as well as leg weakness.
- Cerebral palsy where there is disturbance in the brain function leading to various neuromuscular symptoms.
- Amyotrophic lateral sclerosis (ALS), which is also known as Lou Gehrig’s disease, is a severe neuromuscular disease that causes weakness of the muscles and disability.
- Leg weakness can also be caused by Guillain-Barre syndrome, which is an autoimmune nerve disease.
- Fibromyalgia, which is a chronic condition that causes pain, tenderness and stiffness of the muscles and is known to cause leg weakness.
- Rhabdomyolysis is a disease where there is breakdown or damage to the muscle fibers causing leg weakness.
- Multiple sclerosis is a disease, which affects the spinal cord and brain; and causes weakness, impaired balance and coordination along with other problems.
- Muscular dystrophy is an inherited disorder where there is progressive muscle weakness and loss of muscle tissue.
- Polymyositis is a condition where the patient has muscle weakness along with widespread inflammation.
- Myasthenia gravis is an autoimmune neuromuscular disorder, which causes weakness of the muscles.
Leg Weakness Caused By Drugs & Toxins
Certain medications and toxins can also cause leg and muscle weakness and these include:
- Medications, such as corticosteroids and statins can cause leg weakness.
- Botulinum toxin.
- Organophosphate poisoning.
Leg Weakness Caused By Serious/Life-Threatening Conditions
Leg weakness can occur as a result of serious medical conditions, especially if there is a sudden onset of the weakness and if it is localized to one area of the body. This could be an indication of stroke, which is a life-threatening condition and needs immediate medical attention.
If the patient has a Transient Ischemic Attack (TIA), which is also referred to as mini-stroke and causes stroke-like symptoms, then it can be an indication of an impending stroke. For this reason, TIAs should be taken seriously.
Accompanying Symptoms of Leg Weakness
Patient may experience other symptoms also with weakness in the legs, which depend on the underlying medical condition. Conditions which cause leg weakness can also involve other systems of the body.
Leg Weakness Can Also Accompany Other Leg Symptoms Which Include:
- Muscle spasms in the leg(s).
- Burning feeling in the leg(s).
- Paralysis in the leg(s).
- Numbness in the leg(s).
- Feeling of pins-and-needles in the leg(s).
- Redness, swelling or warmth in the leg(s).
- Twitching in the leg(s).
Leg Weakness Which Accompanies Symptoms that are Related to Other Systems of the Body Includes:
- General feeling of illness or tiredness.
- Pain in the hand, finger or arm.
- Impaired coordination and balance.
- Loss of muscle coordination.
- Tingling sensation in the hands or feet.
- Patient can also have symptoms of multiple sclerosis (MS), which include: weakness, tingling or numbness, problems with vision, fatigue, unsteady walk and depression
Serious Symptoms Accompanying Leg Weakness
In some patients, leg weakness can be a symptom of a fatal or life-threatening medical condition and it is important to seek medical attention in such cases. Life-threatening symptoms, which can accompany leg weakness, are:
- Confusion or changes in mental alertness.
- Changes in taste, hearing or smell.
- Change in level of consciousness.
- High fever, which is more than 101 degrees Fahrenheit.
- Impaired balance and coordination.
- Changes in vision or loss of vision.
- Persistent numbness and weakness in the legs.
- Severe headache.
- Loss of bowel or bladder control.
Diagnosis of the Cause of Leg Weakness
To diagnose the cause of the leg weakness, the patient will be asked a lot of questions by the doctor regarding the leg weakness such as:
- The duration of the leg weakness.
- The part of the leg where the weakness occurs.
- If there has been any recent injury to the leg.
- Other associated symptoms.
- Medications which the patient is taking.
Treatment for Leg Weakness
Leg weakness is often a symptom of some underlying medical condition. The causes of leg weakness are many, so treatment depends on the cause of underlying medical condition, which is causing the leg weakness. When the cause of the leg weakness is treated then patient also finds relief from leg weakness. For example: if the leg weakness is due to a bone fracture in the leg, then treating the fracture by surgery, splinting, braces, physiotherapy etc. will help in relieving the leg weakness along with gradually regaining the strength and flexibility of the leg.
If the cause of the leg weakness is some neurological disorder, then a consultation with the neurologist and appropriate treatment recommended by him/her will alleviate the leg weakness.
Treatment for stroke should be immediately sought, as it is a serious condition, which can cause leg weakness along with other symptoms and also cause serious complications if ignored.
Complications of Leg Weakness
If the cause of leg weakness is some serious condition and the patient does not seek treatment on time, then it can lead to some potential complications and even permanent damage. After the diagnosis of the underlying cause of the leg weakness is made then patient needs to meticulously follow their doctor’s treatment plan to reduce the risk of complications which include: brain damage, disability, paralysis, nerve problems which include pain, tingling or numbness; and chronic or permanent pain.