Exaggerated Startle Response: Why You Startle Easily

What the startle response is

The startle reflex is a fast, automatic reaction to a sudden, unexpected stimulus such as a loud bang. It involves blinking, a facial grimace, hunching the shoulders and tensing the body within a fraction of a second. It is controlled by the brainstem and protects you from harm.

The size of the reflex is turned up or down by the brain's threat system, especially the amygdala. When you feel unsafe, anxious or exhausted, the threshold drops and you startle more. A heightened response is often paired with hypervigilance, constantly scanning for danger.

An exaggerated startle response includes:

• jumping or flinching at ordinary noises such as a door closing or a phone ringing
• startling when someone approaches from behind or touches you
• a racing heart, sweating, shaking or anger after being startled
• taking minutes rather than seconds to settle

Causes of an exaggerated startle response

Post-traumatic stress disorder

Exaggerated startle is one of the arousal symptoms used to diagnose PTSD, along with irritability, poor concentration, sleep problems and hypervigilance. Other PTSD symptoms include intrusive memories, nightmares, flashbacks, avoiding reminders, and negative changes in mood and beliefs, lasting more than a month after a traumatic event. Veterans, survivors of assault or abuse, and people who have been in serious accidents are at higher risk.

Acute stress disorder causes similar symptoms in the first month after trauma. Complex PTSD follows prolonged or repeated trauma, often in childhood.

Anxiety disorders

Generalized anxiety disorder, panic disorder and social anxiety raise baseline arousal, making people jumpy and easily startled.

Sleep deprivation and stimulants

Lack of sleep, caffeine, energy drinks, nicotine, decongestants, and stimulant medicines or drugs increase startle and jitteriness. Alcohol and benzodiazepine withdrawal can cause marked jumpiness.

Neurodevelopmental conditions

People with autism often have heightened sensitivity to sound and touch and stronger startle responses. ADHD and Tourette syndrome are also linked to stronger startle.

Neurological and medical causes

• Hyperekplexia (startle disease): a rare inherited condition. Newborns stiffen rigidly when handled or startled, and later in life people have exaggerated startles that can cause falls because the body stiffens and they cannot put out their hands.
• Startle epilepsy: seizures triggered by sudden stimuli.
• Brain injury and some strokes affecting the brainstem.
• Creutzfeldt-Jakob disease and other rare conditions cause startle-induced jerks (myoclonus) with rapidly progressive memory loss.
• Overactive thyroid increases nervousness and jumpiness.

Culture-bound startle syndromes

Some cultures describe startle-related conditions such as "Jumping Frenchmen of Maine" and latah, in which startle triggers jumping, shouting or imitation.

How doctors assess it

A doctor or mental health professional will ask when the startle began, about traumatic events, nightmares, flashbacks, mood, anxiety, sleep, caffeine, alcohol and drug use, and any falls or stiffening. They may use screening questionnaires for PTSD and anxiety. Blood tests for thyroid function are sometimes useful. Neurological symptoms such as stiffening, falls, jerks or memory loss call for a neurologist and tests such as EEG, MRI or genetic testing.

Treatment

PTSD and trauma

• Trauma-focused psychotherapy: cognitive processing therapy, prolonged exposure therapy and EMDR are first-line treatments recommended by the VA and APA. They reduce hyperarousal including startle.
• Medicines: sertraline, paroxetine, fluoxetine and venlafaxine are used for PTSD. Prazosin is sometimes used for trauma nightmares.

Anxiety

Cognitive behavioral therapy and SSRIs or SNRIs.

Neurological causes

Clonazepam is the main treatment for hyperekplexia. Other neurological causes are treated by a specialist.

Self-help

• Prioritize 7 to 9 hours of sleep with a regular schedule.
• Cut back on caffeine, energy drinks and nicotine, and avoid alcohol as a way to cope.
• Practice slow breathing (in for 4 seconds, out for 6) and grounding techniques: name 5 things you see, 4 you hear, 3 you can touch.
• Regular exercise lowers baseline arousal.
• Arrange your environment so you can see who approaches, and ask others to announce themselves.
• Learn about trauma reactions; understanding that startle is a protective reflex can reduce shame.

Frequently asked questions

Why do I startle so easily?

Common reasons are anxiety, chronic stress, poor sleep, caffeine and, especially, past trauma. After a frightening event, the brain's alarm system can stay on high alert. If jumpiness lasts more than a month with nightmares, flashbacks or avoidance, ask a doctor about PTSD.

Is an exaggerated startle response a sign of PTSD?

It is one of the typical symptoms of PTSD, but it is not enough on its own to diagnose it. PTSD also involves intrusive memories, avoidance, negative mood changes and other arousal symptoms lasting more than a month after trauma. Anxiety and sleep loss can cause jumpiness too.

Can an exaggerated startle response go away?

Yes. When the cause is treated, startle usually lessens. Trauma-focused therapy reduces hyperarousal in PTSD, and better sleep, less caffeine and anxiety treatment help others. Some people remain a little more jumpy than before, but it becomes much less disruptive.

What is hyperekplexia?

Hyperekplexia, or startle disease, is a rare inherited condition. Babies become very stiff when handled or startled, and older children and adults have exaggerated startles that can cause stiff, unprotected falls. It is caused by gene changes affecting glycine receptors and is treated with clonazepam.