Why Is My Leg Shaking?

Leg shaking is typically referred to as a tremor. This is an involuntary muscle contraction, meaning you are not in control of the leg movement.

Leg tremors and other types of shaking may happen for many reasons and are not always a cause for concern. However, there are some conditions that cause leg shaking that may warrant a visit with your healthcare provider. Read on to learn more about what may be causing your legs to shake.  

Restless Leg Syndrome

RLS looks the same as a tremor, however, it is different since it is a voluntary movement of the legs.

People with RLS have an urge to move their legs because of uncomfortable feelings such as tingling, burning, or pain. Itching and crawling sensations in the legs can also be present in people with RLS. These symptoms improve with movement and are typically worse at night.

RLS is commonly seen in people who are pregnant, have diabetes, or are deficient in certain nutrients. That being said, anyone can develop the syndrome.

Tardive Dyskinesia

In some cases, a person can develop shaking legs simply because of the medication they are taking. When that happens, it is referred to as tardive dyskinesia, which is categorized as an involuntary movement disorder.

The movements or shaking can occur throughout the entire body. Medications that can cause tardive dyskinesia include:

• Antipsychotics used to treat mental disorders such as schizophrenia
• Anticholinergic agents used to treat chronic obstructive pulmonary disease (COPD), which is a group of lung disorders, and Parkinson’s disease
• Antidepressants used to treat mental health disorders such as anxiety, depression, and ADHD
• Antiemetics used to treat severe nausea and acid reflux (stomach acid or bile goes back up the food pipe)
• Anticonvulsants used to treat seizures
• Antihistamines used to treat allergy symptoms
• Decongestants used to treat the symptoms of colds and flu
• Antimalarials which are used to prevent and treat malaria (a serious disease caused by a parasite)
• Medications used to treat Parkinson’s disease
• Anxiolytics used to treat anxiety
• Mood stabilizers used to treat bipolar disorder and other mental health disorders
  

Anxiety

Anxiety drives the body into a near-constant state of fight or flight. The fight-or-flight response is a reaction in the body that is designed to alert you to a threat and prepare you to survive. In people with anxiety, things that are not actually threats to one’s survival can set off that stress response in the body.

In people with anxiety, the hormone adrenaline is released at times when it is not needed. It affects the muscles by pumping more blood into them. This response can also cause the legs to shake, and it can generate tremors in other parts of the body.

Stimulant Drugs

Stimulants are substances designed to increase nervous system activity. They can be both prescription and recreational, such as caffeinated drinks.

These drugs can cause tremors to develop in all areas of the body, including the legs. While prescription stimulants can lead to tremors that go away after a person stops using the drug, recreational stimulants such as cocaine and ecstasy may cause a person to develop tremors that do not go away.

MS

Multiple sclerosis is an autoimmune disease, which means the immune system mistakenly attacks healthy cells.

In people with MS, the myelin sheath—the protective coating of nerve cells—becomes damaged by immune system cells. When that happens, the communication pathway between the brain and the body doesn’t function as it should, leading to symptoms.

If a person with MS experiences nerve damage in cells that are in control of their muscle movements, they can develop tremors and leg shaking.

Parkinson's

Parkinson’s disease is a condition that affects the nervous system. People who develop Parkinson’s disease experience uncontrollable movements that progressively worsen over time. Tremors are typically the first warning sign that a person has the disease. Other symptoms of Parkinson’s include:

• Muscle stiffness or rigidity in the arms and legs
• Slow movements
• The loss of reflexes and balance

Alcohol

Alcohol withdrawal can cause tremors that fall under the category of enhanced physiologic tremors. These shaking movements can develop because the use of alcohol can change how the nervous system functions.

Hyperthyroidism

Hyperthyroidism means that you have an overactive thyroid. The thyroid is a gland at the base of the neck. An overactive thyroid produces too many thyroid hormones, which are important hormones that control the way your body uses energy. These hormones play a role in key bodily functions, such as breathing and digestion.

Hyperthyroidism can make your body speed up, causing you to have symptoms such as nervousness and a rapid heartbeat. You may also experience leg tremors.

Dementia

Dementia is often associated with its worst symptom—memory loss. However, the condition does present with other symptoms as well.

One such symptom is leg shaking or tremors. Because the disease is progressive and causes brain damage, it can affect movement in the body over time.

ADHD

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that typically begins in childhood. Neurodevelopmental disorders are considered disabilities and affect how the brain and neurological system functions. The symptoms associated with ADHD include:

• Issues with paying attention
• Difficulties practicing impulse control
• Becoming overly active and having a hard time sitting still

Boredom

You might shake your leg when you're bored as a way to release tension. Boredom may also bring on tics, which are sudden repetitive movements.

Most of the time tics are harmless. If your leg shaking tic is extreme and isn't going away, however, it may be a tic disorder.

When to See a Healthcare Provider

Leg shaking may be worrisome, although it is not always indicative of a serious disease. If you are experiencing other symptoms, including difficulty with walking or standing, trouble controlling your bladder or bowels, cognitive changes, or vision loss, visit a healthcare provider. You may have an underlying health condition that requires treatment.

Summary

Uncontrolled leg movements can have a number of causes, from restless leg syndrome to hyperthyroidism to anxiety. Using certain substances such as alcohol or stimulant drugs can also cause leg shaking.

If you are worried about your leg shaking or if it interferes with your daily life, contact your healthcare provider.