Hyperreflexia: Causes, Types, Symptoms, Prevention, Treatment and Recovery

Definition: is defined as hyperactive or over-sensitive reflexes.

Some examples may include spasmodic or spastic tendons, which are indicative of the disease in the upper motor neuron, as well as the decrease or loss of control normally exerted by the higher brain centers on the lower nerves (disinhibition).


The most common cause of Hyperreflexia is spinal cord injury. A standard stimulus such as filling the bladder can cause excessive reactions of the nervous system. The reasons for these causes are still unknown.

However, hyperreflexia can develop through many other causes, including medication and stimulant side effects, hyperthyroidism , electrolyte imbalance, serotonin syndrome, severe brain trauma, multiple sclerosis, and Reye’s syndrome.

Before knowing the causes and pathophysiology of hyperreflexia, it is important to understand the autonomic nervous system (ANS). The autonomic nervous system is an involuntary part of the nervous system. This means that you have no control over that.

The autonomic nervous system participates in the maintenance of blood pressure, heart rate, respiration, digestion, metabolism and even sexual response. The autonomic nervous system is divided into two, the sympathetic nervous system and the parasympathetic nervous system.

Both act in opposite directions and, therefore, balance the functions of others.

However, in the case of hyperreflexia where there is a lesion above the thoracic vertebra 6, communication between the two autonomous systems is interrupted. Therefore, the stimulation of one is not counteracted by the other, but the condition worsens.

Communication from below the injury can not reach the brain. This lack of coincidence in short can lead to hyperreflexia.

Most of the triggers that cause hyperreflexia originate below the level of spinal cord injury.

This includes; bladder irritation, distended bladder, urinary tract infection, urine retention, pressure pain, ingrown toenails, constipation, hemorrhoids, tight clothing, menstrual cramps, ovarian cysts, bone fractures, etc.


Patellar hyperreflexia . It is the patellar reflex or patellar when a person is in a state of alteration. The same, can be unilateral or bilateral and affect both knees.

Achilleal hyperreflexia . In this case, the reflex here is exalted, and is examined by percussing the Achilles tendon, which causes a contraction of the muscle.


The symptoms of hyperreflexia are the following:

  • High blood pressure
  • Rapid heartbeat
  • Intense and throbbing headache.
  • Blushes on the face.
  • Goosebumps.
  • Daze.
  • Abundant sweating.
  • Nasal congestion.
  • Anxiety and apprehension.
  • Blurry vision.
  • Dilated pupils.
  • Dizziness.
  • Confusion.
  • Spasms of the muscles of the jaw.
  • Fever.


Sometimes, the use of long-term medications and the lack of proper treatment will lead to the serious stage. In these cases it is recommended:

  • Change in the treatment.
  • Control of blood pressure.
  • Control of the nervous system.
  • Control in the leakage of urine.


The treatment depends on the diagnosis of the specific pathology that causes this symptom. If the same, is caused by the use of stimulants or other substances, then the elimination of them, could alleviate these symptoms.

The diagnosis of autonomic hyperreflexia is made by the doctor. This condition, since it is serious and endangers life, needs immediate medical attention. The symptoms of autonomic hyperreflexia are not subtle and may be evident during the time of examination.

This may include pulse and blood pressure. Both are abnormal. Blood pressure is extremely high with rapid pulse.

The doctor initially takes immediate measures to stabilize the patient. Once the blood pressure is controlled, he will look for the underlying cause and try to take all the corrective measures to treat it.

Since there is a risk of stroke, cardiac arrest and retinal hemorrhage, all measures are taken to control blood pressure. At the same time, the doctor tries to eliminate the stimuli. Some quick measures are:

  • The patient is given an antihypertensive medication.
  • They force him to sit down so that the blood flows at his feet.
  • The elimination of tight clothing.
  • If the bladder is distended, it is drained with the help of the catheter. In case the patient is catheterized, the doctor can check the urinary catheter to see if it is blocked. If it is blocked, a new catheter is replaced or the blockage is removed.
  • Treat constipation


The recovery of hyperreflexia can occur between several hours and several months after a spinal cord injury .

Individuals with a severe spinal cord injury usually present a later phase of recovery due to spinal cord shock during the early stages.