What causes muscle rigidity? 21 possible conditions

What Is Muscle Rigidity?

Muscle rigidity is a state of continuous firm, tense muscles with marked resistance to passive movement.

Alternative Names

Muscular rigidity, rigidity, rigor.


Muscle rigidity is an alteration of muscle tone in which the muscles are in an involuntary state of continual tension. Muscle rigidity can be a manifestation of neurological damage (basal ganglia diseases) or a side effect of certain medications. Muscle rigidity is the continuous, tonic contraction of the skeletal muscles, often more marked in the flexor muscles than extensors.

Associated Diagnoses

  • Calcium deficiency disease
  • Cerebral palsy
  • Epilepsy
  • Guillain-Barre syndrome
  • Huntington’s disease
  • Hypoparathyroidism
  • Lou Gehrig’s disease
  • Multiple sclerosis
  • Necrotizing vasculitis
  • Polio
  • Osteomalacia
  • Parkinson’s disease
  • Tetanus
  • Weils disease
  • Spinal cord injury
  • Seizures
  • Stiff-person syndrome
  • Neuroleptic malignant syndrome (NMS)
  • Serotonin syndrome
  • Contractures
  • Side effect of medications

Diagnosis and Treatment

A thorough evaluation by a physician is indicated for muscle rigidity. The evaluation will determine which muscles are affected. Reflexes, sensation and muscle tone will be assessed. If further investigation is needed, the doctor may order diagnostic studies such as a CT scan, MRI, nerve conduction studies or electromyography as well as laboratory tests (drawing blood). The treatment will depend on the underlying problem and the severity of the symptoms.

Call your provider:

Whenever there is muscle rigidity.

Call 911:

  • Whenever there is chest wall rigidity resulting in difficulty breathing
  • If muscle rigidity is resulting in changes in level of consciousness, including agitation and restlessness

Muscle Rigidity News

  • Rigorous Exercise May Boost Benefits of Weight-Loss Surgery
  • Rigors of Ballet Require Careful Training
Read More

See a list of possible causes in order from the most common to the least.



Tetanus is a serious bacterial infection that affects the nervous system and causes muscles to tighten. Commonly called lockjaw, it primarily causes muscle contractions in the jaw and neck. It can be life-threatening.

Read more »


Epilepsy Overview

Epilepsy is a neurological condition caused by malfunctioning brain cells that result in seizures. There is no cure for this disorder but episodes can become less frequent.

Read more »


Parkinson's Disease

Parkinson's disease (PD) is a progressive neurological disorder. It first presents with problems of movement. Smooth and coordinated muscle movements of the body are made possible by a substance in the brain calle...

Read more »


Partial Seizures

A surge in neuron activity causes seizure, resulting in a host of physical symptoms such as muscle contractions, visual disturbances, and blackouts. Partial (focal) seizures affect just one area of the brain.

Read more »


Cerebral Palsy

Cerebral palsy is a disorder of muscle movement and coordination caused by an injury to a child's brain that occurs before birth or during infancy. It affects the part of the brain that controls body movement. Othe...

Read more »



This condition is considered a medical emergency. Urgent care may be required.

Seizures are changes in the brain's electrical activity that cause violent shaking and loss of bodily control. Bruises can result from injuries sustained during a seizure.

Read more »


Spinal Cord Injury

This condition is considered a medical emergency. Urgent care may be required.

A spinal cord injury, or damage to the spinal cord, is an extremely serious type of physical trauma. It will likely have a lasting and significant impact on most aspects of daily life. According to the Nationa...

Read more »


Low Blood Sodium (Hyponatremia)

Low blood sodium, or hyponatremia, occurs when water and sodium are out of balance in your body. A quick drop in sodium levels can cause weakness, headache, nausea, and muscle cramps.

Read more »


Necrotizing Vasculitis

This condition is considered a medical emergency. Urgent care may be required.

Necrotizing vasculitis is the inflammation of blood vessel walls. It can interrupt blood flow, causing skin, muscle, and blood vessel damage, and death of tissues and organs. Its symptoms can affect the entire body.

Read more »


Multiple Sclerosis Overview

Multiple sclerosis (MS) is a chronic autoimmune disease that affects the central nervous system. MS can cause varying symptoms that appear with a wide range of severity, from mild discomfort to complete disability.

Read more »


Calcium Deficiency Disease (Hypocalcemia)

A lack of calcium can lead to diseases like osteoporosis and calcium deficiency disease (hypocalcemia). Severe deficiency can result in numbness and tingling in the mouth, lips, hands and feet, among other signs.

Read more »


Huntington's Disease

Huntington's disease is a hereditary condition in which the brain's nerve cells gradually break down. This affects physical movements, emotions, and cognitive abilities. There is no cure, but there are ways to cope wit...

Read more »


Guillain-Barre Syndrome

This condition is considered a medical emergency. Urgent care may be required.

Guillain-Barre syndrome is a rare but serious autoimmune disorder in which the immune system attacks healthy nerve cells of the peripheral nervous system. This leads to weakness, numbness, and tingling, and ca...

Read more »


Slipped (Herniated) Disk

The vertebrae in your spine are cushioned by disks composed of a hard outer ring with a gelatinous material inside. Injury or weakness can cause the inner portion of the disk to break through the outer portion.

Read more »



Hypoparathyroidism occurs when the parathyroid glands in the neck don't produce enough hormone (PTH). Too little PTH causes low calcium and high phosphorus levels in the body. Many of its symptoms concern low calciu...

Read more »


Arterial Embolism

This condition is considered a medical emergency. Urgent care may be required.

An arterial embolism is a blood clot that has become stuck in the arteries. This can block or restrict blood flow, causing tissue damage or death in the affected area. Clots generally affect the arms, legs, or feet.

Read more »


ALS (Lou Gehrig's Disease)

Amyotrophic Lateral Sclerosis (ALS) is not contagious. It is a degenerative disease that affects the brain and spinal cord. A chronic disorder, it causes a loss of control of voluntary muscles. The nerves controllin...

Read more »



Poliomyelitis, or polio, is a highly contagious disease that is caused by a virus that attacks the body's nervous system. It is most likely to be contracted by children under five years old.

Read more »



Osteomalacia is a weakening of the bones due to problems with bone formation or the bone building process. It is not the same as osteoporosis, which is a weakening of living bone that has already been formed and i...

Read more »


Weils Disease

Weil's disease is a severe form of the bacterial infection leptospirosis, which can lead to organ failure and bleeding. Symptoms include nausea, fever, headache, and jaundice.

Read more »

This feature is for informational purposes only and should not be used to diagnose.
Please consult a healthcare professional if you have health concerns.
Add another symptom to narrow down the possibilities

I'm experiencing:

Choose from list of symptoms: