How does a spinal cord injury affect sweating?

The sympathetic nerves that control sweating leave the spinal cord and are normally coordinated by the brain. A spinal cord injury interrupts that control, so sweating can be reduced or absent in some areas below the injury and excessive in others. The pattern depends on the level and completeness of the injury.

What is autonomic dysreflexia?

It is a sudden, dangerous rise in blood pressure seen in people with spinal cord injury, typically at or above the T6 level. It is triggered by a stimulus below the level of injury, most often a full or blocked bladder, that sets off a strong sympathetic reflex the brain can no longer control.

Why does autonomic dysreflexia cause sweating?

During an episode, the body reacts to the surge in blood pressure with sweating and flushing above the level of injury, while the skin below the injury can turn pale and cool. The sweating above the level is one of the recognizable warning signs alongside a pounding headache.

Which spinal cord injuries can cause autonomic dysreflexia?

It is most associated with injuries at or above the T6 level. Reported rates in this group range widely, roughly 48% to 90%, depending on how complete the injury is, how the event is defined, and the population studied.

What are the warning signs of autonomic dysreflexia?

Common features include a sudden spike in blood pressure, a pounding headache, sweating and flushing above the injury, pale and cool skin with goosebumps below it, nasal congestion, a slow heart rate, and anxiety. It is a medical emergency, and people with SCI are usually taught a specific action plan for it.

Is this page medical advice?

No. It is an educational summary of how spinal cord injury affects sweating and what autonomic dysreflexia is, drawn from published sources. It is not a diagnosis or a management plan, and anyone living with SCI should follow the individualized guidance of their care team.

Research

Spinal Cord Injury, Sweating, and Autonomic Dysreflexia

Sweating is controlled by sympathetic nerves that leave the spinal cord, so a spinal cord injury (SCI) can disrupt it. Depending on the level and completeness of the injury, sweating may be reduced in some areas and increased in others. In higher injuries, sweating can also be one of the visible signs of autonomic dysreflexia, a sudden and dangerous rise in blood pressure triggered by something the body cannot feel below the level of injury. This page explains how SCI affects sweating and what autonomic dysreflexia is. It is educational and is not medical advice; autonomic dysreflexia is a medical emergency.

By the Sweat Explained Editorial Team · Published 2026-07-20 · Last reviewed 2026-07-20 · Educational information, not medical advice.

Key statistics at a glance

At or above T6
the injury level at or above which autonomic dysreflexia typically occurs
Krassioukov 2009 (Arch Phys Med Rehabil)
48% to 90%
reported range of people with spinal cord injury at or above T6 who experience autonomic dysreflexia
Krassioukov 2009 (Arch Phys Med Rehabil)
Bladder
a full or blocked bladder is the most common trigger for autonomic dysreflexia; bowel issues are the next most common
Cragg & Krassioukov 2012 (CMAJ)
20 mmHg
a rise in systolic blood pressure of about this much above baseline is used to define autonomic dysreflexia in adults
Krassioukov 2012 (J Spinal Cord Med)
Above the level
in autonomic dysreflexia, sweating and flushing appear above the injury, with pale, cool skin below it
Eldahan & Rabchevsky 2018 (Auton Neurosci)

How spinal cord injury disrupts sweat control

The sympathetic nerves that switch sweat glands on originate in the thoracic and upper lumbar spinal cord and travel outward to reach the skin. The brain normally coordinates these nerves from above. A spinal cord injury interrupts that communication, so the brain can lose reliable control over sympathetic outflow below the level of the injury (Karlsson 2006).

The consequences for sweating depend on where the injury is and how complete it is. Signals from the brain may no longer reach some sweat nerves, while spinal reflexes below the injury can fire without the brain's usual moderation. This is why sweating after SCI can be patchy and unpredictable rather than simply reduced or increased everywhere.

Patterns of sweating after injury

Several patterns are described after spinal cord injury. Some people have reduced or absent sweating in regions below the level of injury, because those sweat nerves have lost their normal signals, which can make temperature control harder in hot conditions. Others experience excessive sweating, sometimes above the level of injury as a form of compensation, and sometimes as episodic sweating tied to reflex activity below the injury (Karlsson 2006).

Sweating can also appear as part of specific reflexes. It may accompany bladder or bowel activity, and, most importantly, it is one of the recognizable features of autonomic dysreflexia. Because sweating after SCI can be a clue to what the nervous system is doing below the level of injury, clinicians pay attention to when and where it occurs.

What autonomic dysreflexia is

Autonomic dysreflexia is a sudden, potentially dangerous rise in blood pressure that occurs in people with spinal cord injury, typically at or above the T6 level (Krassioukov 2009). It is set off by a stimulus below the level of injury that the person often cannot feel, most commonly a full or blocked bladder, but also bowel distension, skin irritation, or other causes (Cragg & Krassioukov 2012).

The mechanism is a reflex the brain can no longer control. The stimulus triggers a strong sympathetic response below the injury, causing blood vessels there to constrict and blood pressure to climb. Normally the brain would counteract this, but its signals cannot pass the injury, so the blood pressure keeps rising. Above the level of injury the body reacts to the high pressure with flushing and sweating, while below it the skin can turn pale and cool. A rise in systolic blood pressure of roughly 20 mmHg above the person's baseline is used to define the event in adults (Krassioukov 2012).

Signs and common triggers of autonomic dysreflexia

Recognizing autonomic dysreflexia quickly matters. Reviews describe the following features and triggers (Krassioukov 2009; Cragg & Krassioukov 2012; Eldahan & Rabchevsky 2018):

Sudden high blood pressure. A sharp rise above the person's usual (often low) baseline is the central feature.
Pounding headache. A severe, throbbing headache is a classic warning sign.
Sweating and flushing above the injury. Profuse sweating and reddening of the face, neck, and shoulders are common.
Pale, cool skin and goosebumps below the injury. The opposite response occurs below the level of injury.
Slow heart rate, nasal congestion, blurred vision, or anxiety. Other frequently reported features.
Common triggers. A full or blocked bladder is the most common, followed by bowel distension, then skin problems such as pressure areas, tight clothing, or ingrown nails, and other painful stimuli below the injury.

Why autonomic dysreflexia is an emergency

Autonomic dysreflexia is a medical emergency because the blood pressure can rise high enough to cause serious harm, including stroke, seizures, or other complications if it is not addressed (Krassioukov 2009; Eldahan & Rabchevsky 2018). The severity comes from how quickly and how high the pressure can climb, particularly against a baseline that is often unusually low in people with high spinal cord injuries.

Established clinical guidance emphasizes recognizing the episode, sitting the person upright, loosening tight clothing, and urgently looking for and removing the trigger, most often relieving the bladder. Many people with SCI and their caregivers are taught a specific plan for this, and specialist guidance should be followed. This page explains what autonomic dysreflexia is so it can be recognized; it is educational and is not a substitute for the individualized medical guidance a person with SCI should have.

What this means in plain terms

Sweating changes after a spinal cord injury because the injury interferes with the sympathetic nerves that control the sweat glands. That can mean less sweating in some areas and more in others, and it can make sudden sweating a meaningful signal. In injuries at or above T6, sweating and flushing above the level of injury, together with a pounding headache and a spike in blood pressure, can be signs of autonomic dysreflexia, which needs urgent action.

For a general reader, the key point is that in the context of spinal cord injury, sweating is not just about temperature; it can be a window onto the autonomic nervous system and, at times, an early warning. This page describes recognized associations and physiology; it is educational, not a diagnosis, and anyone living with SCI should rely on the specific guidance of their care team.

Methodology and limitations

This page draws on peer-reviewed sources: a systematic review of the management of autonomic dysreflexia after spinal cord injury (Krassioukov et al., Arch Phys Med Rehabil 2009), an open-access clinical summary of autonomic dysreflexia (Cragg & Krassioukov, CMAJ 2012), a review of the pathophysiology and management of autonomic dysreflexia (Eldahan & Rabchevsky, Auton Neurosci 2018), a review of autonomic dysfunction and its clinical signs after SCI including sweating (Karlsson, Prog Brain Res 2006), and international standards documenting autonomic function after SCI (Krassioukov et al., J Spinal Cord Med 2012). The injury level, prevalence range, common triggers, and blood-pressure definition were traced to those sources.

Limitations: the reported prevalence of autonomic dysreflexia varies widely (roughly 48% to 90%) depending on injury level and completeness, how it is defined, and the population studied, so a single figure would be misleading. Sweating patterns after SCI are individual and depend on the level and completeness of injury. This page describes recognized associations and is not a diagnosis or a management plan; autonomic dysreflexia is a medical emergency, and people with SCI should follow the individualized guidance of their care team.

Frequently asked questions

How does a spinal cord injury affect sweating?: The sympathetic nerves that control sweating leave the spinal cord and are normally coordinated by the brain. A spinal cord injury interrupts that control, so sweating can be reduced or absent in some areas below the injury and excessive in others. The pattern depends on the level and completeness of the injury.
What is autonomic dysreflexia?: It is a sudden, dangerous rise in blood pressure seen in people with spinal cord injury, typically at or above the T6 level. It is triggered by a stimulus below the level of injury, most often a full or blocked bladder, that sets off a strong sympathetic reflex the brain can no longer control.
Why does autonomic dysreflexia cause sweating?: During an episode, the body reacts to the surge in blood pressure with sweating and flushing above the level of injury, while the skin below the injury can turn pale and cool. The sweating above the level is one of the recognizable warning signs alongside a pounding headache.
Which spinal cord injuries can cause autonomic dysreflexia?: It is most associated with injuries at or above the T6 level. Reported rates in this group range widely, roughly 48% to 90%, depending on how complete the injury is, how the event is defined, and the population studied.
What are the warning signs of autonomic dysreflexia?: Common features include a sudden spike in blood pressure, a pounding headache, sweating and flushing above the injury, pale and cool skin with goosebumps below it, nasal congestion, a slow heart rate, and anxiety. It is a medical emergency, and people with SCI are usually taught a specific action plan for it.
Is this page medical advice?: No. It is an educational summary of how spinal cord injury affects sweating and what autonomic dysreflexia is, drawn from published sources. It is not a diagnosis or a management plan, and anyone living with SCI should follow the individualized guidance of their care team.

Sources

Primary peer-reviewed studies and official sources first, then reviews and institutional framing (secondary).

Krassioukov A, Warburton DE, Teasell R, Eng JJ; SCIRE Research Team. A systematic review of the management of autonomic dysreflexia after spinal cord injury. Arch Phys Med Rehabil. 2009;90(4):682-695. Injury level, prevalence range, and management of autonomic dysreflexia. Journal
Cragg J, Krassioukov A. Autonomic dysreflexia. CMAJ. 2012;184(1):66. Open-access clinical summary of triggers and the blood-pressure definition. Full text
Eldahan KC, Rabchevsky AG. Autonomic dysreflexia after spinal cord injury: systemic pathophysiology and methods of management. Auton Neurosci. 2018;209:59-70. Mechanism, signs (including sweating), and complications. (secondary) Journal
Karlsson AK. Autonomic dysfunction in spinal cord injury: clinical presentation of symptoms and signs. Prog Brain Res. 2006;152:1-8. Autonomic control after SCI, including sweating changes. (secondary) Journal
Krassioukov A, Biering-Sorensen F, Donovan W, et al. International standards to document remaining autonomic function after spinal cord injury. J Spinal Cord Med. 2012;35(4):201-210. Defines autonomic dysreflexia and related autonomic assessment. (secondary) Journal

How to cite this page

Sweat Explained. Spinal Cord Injury, Sweating, and Autonomic Dysreflexia. Published 2026-07-20; last reviewed 2026-07-20. Available at: https://sweatexplained.com/research/spinal-cord-injury-and-sweating

Please cite the original studies for the underlying figures. Journalists are welcome to link to this page; the charts are original renderings of the cited data.