FND Symptoms

The following article is an excerpt from Chapter 9 of my book, FND Recovery: Seven Evidence-Based Steps to Heal Functional Neurological Disorder (Volume 1)

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9.6 Common Symptoms – A Comprehensive Overview of FND’s Impact on Body and Mind

Complete List of FND Symptoms

While my experience with Functional Neurological Disorder (FND) was severe, I recognize that FND manifests in many different ways. Some individuals experience symptoms I didn’t face, such as chronic pain. To create a comprehensive list of FND symptoms, I reached out to the broader FND community. In January 2025, I polled my Facebook support group, “Facing FND – It’s real! (functional neurological disorder support group),” which at the time had just over 600 members. I encouraged people to share their symptoms without worrying about perfect wording. I used ChatGPT to reword their responses and eliminate duplicates, making it easier for those already dealing with cognitive difficulties.

For the most complete list possible, I also added in my own symptoms as well as symptoms shown in other research. Here is the compiled list of symptoms, formatted for ease of reading. You can also visit our group, where the raw data from this poll is available, and feel free to add your own symptoms there as well.

Fluctuating Symptom Severity:

While not a specific “symptom,” the unpredictable nature of FND is a hallmark of the condition. Symptoms can fluctuate in intensity or change from day to day. This variability is important for setting patient expectations and helping clarify the clinical picture.

Additionally, there are a few key patterns to note:

• Symptoms are often localized to one side of the body.

• Almost all symptoms occur intermittently, meaning they come and go rather than being constant.

• Many symptoms are interconnected and can occur in a specific order or progression.

Now let’s dive in to the specifics.

Seizures and Tremors

Seizures are a common symptom in Functional Neurological Disorder (FND), but understanding them can be confusing due to the variety of terms and types. To make things easier to grasp, let’s break it down into three simple concepts:

1. Shaking vs. No Shaking: Some seizures involve shaking or tremors, while others don’t. You might see someone physically tremble or jerk, but in other cases, the seizure could look like a loss of awareness without any visible shaking.

2. Awareness of the Seizure: In some types of seizures, the person experiencing them may be fully aware of what’s happening, while in others, they may have no memory of the event at all.

3. Non-Epileptic: The most important thing to know is that all of these seizures in FND are non-epileptic. That means, unlike epileptic seizures, they don’t involve abnormal electrical activity in the brain. They still affect the body in similar ways, but they stem from a different cause.

Once you understand these three points, the many different types of FND seizures start to make more sense. Now, let’s dive into the specific types, though you don’t need to memorize every term—just keep in mind that they all share these core features.

Here are the various types of seizures commonly experienced by people with FND:

Non-Epileptic Seizures (NES)

These seizures are often mistaken for epileptic seizures due to symptoms like shaking or jerking. However, they are not triggered by the electrical disturbances typically found in epilepsy. Instead, they reflect a breakdown in how the body and brain interact, without the abnormal brain activity seen in epileptic seizures (Devinsky, 2011).

Dissociative Seizures

A dissociative seizure can be particularly disorienting. During these episodes, an individual may experience a profound sense of detachment from their own body or the world around them. There’s no shaking involved, but the person may lose touch with reality, as though they’re watching themselves from a distance. These moments can be confusing, frightening, and deeply isolating for both the person experiencing them and their loved ones (Pick et al., 2016; Eaves, 2024; Schmutz, 2013).

Functional Seizures

This umbrella term covers a range of non-epileptic seizures. Symptoms can include shaking, jerking, or even a complete loss of motor control. They are often triggered by emotional stress, traumatic experiences, or physical exertion. The unpredictability of these seizures can make daily life feel like an emotional roller coaster, and they are frequently misunderstood by those unfamiliar with FND (Duque et al., 2023; Asadi-Pooya et al., 2020; Asadi-Pooya et al., 2023).

Functional Impaired Awareness Seizures (FIAD)

During FIAD, a person may lose awareness of their surroundings and even have no memory of the episode once it’s over. The person may continue moving around during the seizure, but their actions are automatic, as if on autopilot. For those of you who experience this, the lack of memory afterward can be unsettling, leaving us feeling disconnected from our own bodies. I have never experienced such an episode — at least I don’t think I have. 😂

Functional Tremors

One of the more visible symptoms of FND, functional tremors often appear as involuntary shaking, but without the abnormal brain activity seen in conditions like Parkinson’s disease. For me, it was my right forearm and hand that would uncontrollably flap like a fish—what some would call a “princess wave.” This tremor, though localized, can be deeply disorienting and, for many with FND, it’s often confined to one side of the body. I’ve found several others who share the same experience, and it’s a symptom that warrants more research.

Myoclonic Seizures

Myoclonic seizures involve sudden, involuntary jerks or twitches of a muscle or group of muscles. These can happen without warning and are not caused by the electrical activity typically seen in epileptic myoclonus. Though brief, they can be deeply unsettling, especially when they occur in rapid succession (Striano & Belcastro, 2012; Nijsen et al., 2010).

Panic-like Seizures

While panic attacks are often thought of as psychological events, in FND, panic-like seizures are neurological in origin. These seizures can involve shortness of breath, dizziness, heart palpitations, and a sense of impending doom, much like a panic attack. However, these symptoms are not triggered by psychological stress, but by an underlying neurological dysfunction that mimics the signs of a panic attack without the typical emotional triggers (Hallett et al., 2022). This could explain why I often felt like I was having a panic attack when I had nothing to panic about. My body was just overloaded.

Conclusion

Living with FND seizures is like being trapped in a body that betrays you, where each seizure feels like a new wave of confusion and fear. And yet, through understanding and awareness, there is hope. The more we talk about these symptoms—whether tremors, dissociation, or myoclonic jerks—the more we can shine a light on a disorder that has long been misunderstood. I can say from personal experience that healing is possible. It’s not easy, and it’s not quick, but it is possible.

Motor Symptoms in FND (Movement & Coordination)

Impaired Mobility and Coordination

• Difficulty walking or standing without assistance.

• Neck, shoulders, and legs feel heavy and painful when walking.

• Heaviness or paralysis in limbs (can cause one leg to drag while walking).

• Balance problems and dizziness.

Functional Cognitive-Motor Slowing

• Reduced speed and coordination of both physical movements and thought processes.

Sudden Falls and Instability

• Unexpected falls or a sudden inability to maintain posture, including:

• Sudden neck falls (unable to support the head).

• Frequent trips and falls due to lack of balance.

Movement Abnormalities

• Myoclonus: Sudden, involuntary jerking or twitching of a muscle or muscle group.

• Tics: Involuntary, repetitive movements or sounds.

• Facial Spasms: Spasms in the left side of the face, starting around the eye.

• Body Spasms: Left-sided body spasms starting with the eye.

Dystonia (Involuntary Muscle Contractions)

• General intermittent dystonia: Repetitive or twisting movements, or abnormal postures.

• Left-sided posturing dystonia: Specific muscle contractions on the left side of the body.

• Uncontrollable movement: Can feel like a ratchet screwdriver or a flopping fish, causing sudden, jerky motion.

Paralysis

• Partial Paralysis: Can involve either the left or right side of the body, sometimes both.

• Temporary paralysis from the waist down, often following a seizure.

• Paralysis from the neck or ribs down after seizures.

• Full paralysis from the neck down at times.

• Paralyzed leg stays behind during walking.

Weakness

• Right-sided weakness: Reduced strength or coordination on the right side of the body.

• Left-sided weakness: Reduced strength or coordination on the left side.

• Muscle weakness in arms and legs, making it difficult to perform daily tasks.

• Shoulder and arm weakness: Difficulty with arm movements, often leading to a sensation of heaviness.

Cognitive Symptoms in FND

Cognitive Fog

• Difficulty thinking clearly, feeling as though you’re in a haze or fog.

• Everything that isn’t routine or habitual can become overwhelming and trigger panic symptoms.

Thinking and Processing Delays

• Slowness in thinking or processing information, making it hard to keep up with normal tasks.

• Trouble switching between tasks or multitasking, leading to a sense of being “stuck.”

Confusion and Disorientation

• A sense of confusion or inability to think straight, which can interfere with basic decision-making.

• Periods of disorientation where the mind feels trapped inside the body.

• Difficulty with memory

Blackouts and Loss of Consciousness

• Blackouts: Periods of time where memory is completely blank, or the person is unaware of what happened.

• Hallucinations: Experiencing things that aren’t there, including auditory, visual, or sensory distortions.

• Loss of consciousness: Episodes of fainting or passing out, often without warning.

Feeling “Drunk” or Disconnected

• Cognitive impairment can feel like being “drunk” 24/7, even without drinking, leading to an overwhelming sense of disconnection from reality.

• This symptom is mixed with balance issues, and it can feel quite embarrassing to be out in public with your family when FND makes you literally look and act drunk — and you haven’t swallowed a drop.

Overall Cognitive Impairment

• General difficulty with thinking, making decisions, and concentrating.

• Unable to think clearly, which may interfere with daily activities, work, or social interactions.

Speech Symptoms in FND

Speech Impairment

• Individuals may experience difficulty with verbal communication, including slowness, hesitation, or difficulty articulating words. This can affect the clarity and fluidity of speech.

Loss of Words

• A common symptom is the inability to recall or find the right words during conversation. This can lead to interruptions in speech or long pauses while the speaker tries to remember the word he is searching for.

Slurred Speech

• Slurred speech, where words become mumbled or unclear, is often experienced, particularly during times of fatigue or distress. This can make communication more challenging and may be mistaken for intoxication.

Stuttering

• Some individuals may develop stuttering or speech disruptions where they get stuck on certain words or sounds. This can result in difficulty completing sentences or a sense of frustration when trying to communicate.

Vocal Paresis

• Vocal paresis refers to partial paralysis of the vocal cords, causing a hoarse or weak voice. Individuals might find it hard to project their voice or speak loudly enough for others to hear clearly.

Voice Loss After Swallowing

• After swallowing, some individuals may experience temporary voice loss or difficulty speaking. This can be linked to disruptions in the neurological pathways responsible for both swallowing and speech.

Trouble Speaking

• General difficulty with speaking can occur, ranging from mild struggles with clarity to complete inability to form coherent sentences. This may be episodic or persistent, depending on the individual’s condition.

Inability to Speak at Times

• During certain episodes, individuals may completely lose the ability to speak. This could be due to muscle dysfunction or neurological issues affecting the speech centers of the brain.

Pain Symptoms in FND

Migraines / Headaches

• Intense headaches or migraines that can vary in severity and duration.

Neuropathy

• Nerve damage leading to pain, weakness, numbness, or tingling, typically in the hands and feet (peripheral neuropathy).

Joint Pain

• General pain in the joints, which may be persistent or episodic.

Muscle Pain

• Ongoing or sharp pain in the muscles, often described as achy or throbbing.

Excruciating Limb Pain

• Sudden, intense pain in the arms or legs, sometimes linked to nerve irritation or inflammation.

Sudden Pain

• Sharp, unanticipated pain that may appear suddenly and can affect various parts of the body.

Whole Body Pain

• A widespread pain sensation that can feel like it’s affecting the entire body, often exacerbating other symptoms.

Tendon & Ligament Pain (Groin)

• Pain in specific areas, such as the groin, due to tendon or ligament issues.

Temperature Regulation Symptoms in FND

Temperature Sensitivity (Hot & Cold)

• Individuals with FND may experience extreme sensitivity to temperature changes, feeling too hot or too cold in situations where others feel comfortable.

Chills in Warm Environments

• Even in warm or hot environments, some may experience chills, a sensation of coldness, or shivering.

Overheating & Flushed Face

• Some individuals may struggle with overheating, leading to a flushed or reddened face, often accompanied by discomfort or sweating.

Hearing Regulation Symptoms in FND

Noise Sensitivity (Hyperacusis)

• People with FND may experience an exaggerated sensitivity to sounds, finding normal or everyday noises painfully loud or overwhelming.

Super Hearing

• Some individuals may develop heightened hearing abilities, where sounds seem louder or more distinct than usual, often contributing to sensory overload.

Gradual Hearing Loss

• Over time, individuals with FND might notice a gradual decrease in hearing, which may affect one or both ears and can be distressing.

Vision Regulation Symptoms in FND

Visual Overstimulation

• Individuals with FND may become easily overwhelmed by visual stimuli, such as bright lights, fast-moving objects, or crowded environments, leading to discomfort or disorientation.

Vision Problems

• People with FND can experience a range of visual disturbances that affect their ability to see clearly, including blurriness or distortion.

Double Vision (Diplopia)

• Double vision, or seeing two images of a single object, can occur, making it difficult for individuals to focus and navigate.

Light Sensitivity (Photophobia)

• Intense sensitivity to light, particularly bright lights or sunlight, can cause significant discomfort, headaches, or even nausea.

Loss of Vision in One Eye

• Some individuals may experience a sudden or gradual loss of vision in one eye, leading to partial or total blindness in that eye.

Tunnel Vision

• Tunnel vision, or the narrowing of the visual field, often occurs in one eye, making it harder to see objects outside of the central focus.

Haze or Halo in Vision

• A haze or halo effect around objects can distort the clarity of vision, making it appear as if everything is surrounded by a blurry glow or fog.

Inability to See Hands

• Some individuals may experience moments when they cannot see their hands clearly, as if they are temporarily invisible or obscured from their view.

Other Sensory Symptoms in FND

Muscle Discomfort (as part of the “Fight or Flight” response)

• Individuals may feel as though their muscles are constantly tensed and ready for conflict, even when no actual danger is present. This can cause chronic discomfort and a sensation of being physically “on edge.”

Pins & Needles / Numbness

• Sensations of tingling or numbness in various parts of the body, often affecting the hands, feet, or limbs, can occur. These sensations may be persistent or intermittent.

Muscle Spasms and Twitching and Drooping

• Involuntary muscle movements, including visible twitches under the skin, can be common. These spasms might be localized or affect larger muscle groups. One person even said the left side of the mouth sometimes drooped.

Connective Tissue or Smooth Muscle Spasms

• Beyond skeletal muscle spasms, connective tissue or smooth muscle spasms (in muscles that control internal organs) may also happen, contributing to a wide range of uncomfortable sensations.

Internal Tremors

• Some individuals experience the feeling of constant internal movement without any actual physical movement. These internal tremors can be unsettling and difficult to explain to others, as they are not visible.

Physical Dissociation

• Individuals may have episodes where they feel disconnected from their own body, such as an inability to feel their legs or feet. In some cases, it may even feel as though a part of the body (like a limb) is no longer attached.

Sleep and Fatigue Symptoms in FND

Chronic Fatigue

• Many individuals with FND experience persistent, overwhelming fatigue that doesn’t improve with rest. This type of fatigue can interfere with everyday activities and can feel like a constant drain on energy.

Trouble Sleeping

• Difficulty falling asleep, staying asleep, or experiencing restless sleep is common. Sleep disturbances can exacerbate other symptoms of FND, such as cognitive fog and increased sensitivity to pain.

Sleep Issues

• In addition to trouble falling asleep, some people may experience fragmented sleep, waking up frequently during the night, or feeling unrested upon waking up.

Fatigue

• Fatigue is often felt throughout the day and can be debilitating, leaving individuals feeling drained and unable to function optimally. It may not be alleviated by sleep, and the severity can vary throughout the day.

Emotional and Behavioral Symptoms in FND

Fight, Flight, Freeze, Fawn Response (FFFF)

• The body’s natural response to stress or perceived danger, which can be exaggerated in FND. Individuals may experience intense emotional reactions that feel out of proportion to the situation.

Startling Easily

• People with FND may have heightened sensitivity to sudden stimuli, causing them to startle easily or react strongly to noises, movements, or changes in their environment.

Screaming Episodes

• Some individuals may experience episodes of uncontrollable screaming or vocal outbursts, often as a reaction to stress or overwhelming emotions.

Struggle with Change

• Transitioning to new situations or changes in routine can be difficult, leading to feelings of anxiety, confusion, or emotional distress. This can make managing everyday life challenging.

Additional Research Backed Symptoms

Autonomic Dysregulation

Some people with FND experience autonomic dysfunction, which goes beyond temperature sensitivity. Symptoms of this may include:

• Orthostatic intolerance: Feeling lightheaded or having a rapid heart rate when standing.

• Gastrointestinal issues: Nausea or irregular bowel habits.

• Bladder dysfunction: Urinary retention or incontinence.

• While some of these symptoms overlap with other categories (e.g., dizziness), it’s important to note autonomic dysregulation, as it highlights the disruption in brain-body communication that is often seen in FND (Mayo Clinic, n.d.; FND Hope, n.d).

Broader Dissociative Symptoms:

In addition to physical dissociation (like not feeling your legs), many people with FND experience other dissociative symptoms, such as:

• Depersonalization: Feeling detached from your own thoughts or emotions.

• Derealization: Feeling disconnected from your surroundings or reality.

These experiences are well-documented in FND research (Campbell et al., 2023; Brown, 2016; Perez et al., 2018) and can offer a more complete understanding of the condition.

Other Symptoms & Conditions Mentioned by FND Patients

• Coexisting Connective Tissue Disorder (hEDS - Hypermobile Ehlers-Danlos Syndrome): A condition that affects the connective tissues, leading to hypermobility of the joints and potentially contributing to symptoms like joint pain, dislocations, and skin that bruises or scars easily.

• Coexisting Fibromyalgia: A chronic condition characterized by widespread muscle pain, tenderness, and other symptoms like fatigue, sleep disturbances, and difficulty concentrating.

• Coexisting Chronic Fatigue: Persistent and severe fatigue that doesn’t improve with rest and is often associated with other symptoms, affecting day-to-day functioning.

• Coexisting TMJ from Seizures: Temporomandibular joint (TMJ) dysfunction caused or worsened by the physical stress of seizures, leading to jaw pain, headaches, or difficulty chewing.

• Skin Peels Mostly on Hands and Eyelids: Dry, peeling, or flaking skin, particularly on the hands and eyelids, which may be related to the stress or physical symptoms of FND.

• Hair Loss: Hair thinning or loss, which can result from stress, chronic illness, or as a side effect of other FND-related factors.

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References:

Asadi-Pooya, A. A., Brigo, F., Mildon, B., & Nicholson, T. R. (2020). Terminology for psychogenic nonepileptic seizures: Making the case for “functional seizures”. Epilepsy & Behavior, 104, 106895. https://www.sciencedirect.com/science/article/abs/pii/S1525505019313381

Asadi-Pooya, A. A. (2023). Incidence and prevalence of psychogenic nonepileptic seizures (functional seizures): a systematic review and an analytical study. International Journal of Neuroscience, 133(6), 598-603.

Brown, R. J. (2016). Dissociation and functional neurologic disorders. Handbook of clinical neurology, 139, 85-94. https://www.sciencedirect.com/science/article/abs/pii/B9780128017722000084

Campbell, M. C., Smakowski, A., Rojas-Aguiluz, M., Goldstein, L. H., Cardeña, E., Nicholson, T. R., … & Pick, S. (2023). Dissociation and its biological and clinical associations in functional neurological disorder: systematic review and meta-analysis. BJPsych Open, 9(1), e2. https://www.cambridge.org/core/journals/bjpsych-open/article/dissociation-and-its-biological-and-clinical-associations-in-functional-neurological-disorder-systematic-review-and-metaanalysis/5434702F57E81BB6A85624AD07DC5C50

Eaves, L. (2024). An Interpretative Phenomenological Analysis of the Experience of Self-Disgust in people with Functional/dissociative Seizures. https://etheses.whiterose.ac.uk/id/eprint/35509/

Devinsky, O., Gazzola, D., & LaFrance Jr, W. C. (2011). Differentiating between nonepileptic and epileptic seizures. Nature Reviews Neurology, 7(4), 210-220. https://www.nature.com/articles/nrneurol.2011.24

Duque, L., Garza, I., Cascino, G. D., & Staab, J. P. (2023). Functional neurological seizures and migraine: a systematic review and case series. Epilepsy & Behavior, 147, 109437. https://www.sciencedirect.com/science/article/abs/pii/S1525505023003566

FND Hope. (n.d.). Sensory Changes – Symptoms. https://fndhope.org/fnd-guide/symptoms/sensory-changes/FND Hope International

Hallett, M., Aybek, S., Dworetzky, B. A., McWhirter, L., Staab, J. P., & Stone, J. (2022). Functional neurological disorder: New subtypes and shared mechanisms. The Lancet Neurology, 21(6), 537–550. https://pmc.ncbi.nlm.nih.gov/articles/PMC9107510/

Mayo Clinic. (n.d.). Autonomic neuropathy. Retrieved April 26, 2025, from https://www.mayoclinic.org/diseases-conditions/autonomic-neuropathy/symptoms-causes/syc-20369829

Nijsen, T. M., Aarts, R. M., Cluitmans, P. J., & Griep, P. A. (2010). Time-frequency analysis of accelerometry data for detection of myoclonic seizures. IEEE Transactions on Information Technology in Biomedicine, 14(5), 1197-1203. https://ieeexplore.ieee.org/abstract/document/5523946

Perez, D. L., Matin, N., Williams, B., Tanev, K., Makris, N., LaFrance Jr, W. C., & Dickerson, B. C. (2018). Cortical thickness alterations linked to somatoform and psychological dissociation in functional neurological disorders. Human brain mapping, 39(1), 428-439. https://onlinelibrary.wiley.com/doi/abs/10.1002/hbm.23853

Pick, S., Mellers, J. D., & Goldstein, L. H. (2016). Emotion and dissociative seizures: a phenomenological analysis of patients’ perspectives. Epilepsy & Behavior, 56, 5-14. https://www.sciencedirect.com/science/article/abs/pii/S1525505015006654

Schmutz, M. (2013). Dissociative seizures-A critical review and perspective. Epilepsy & Behavior, 29(3), 449-456. https://www.sciencedirect.com/science/article/abs/pii/S152550501300423X

Striano, P., & Belcastro, V. (2012). Treatment of myoclonic seizures. Expert Review of Neurotherapeutics, 12(12), 1411-1418. https://www.tandfonline.com/doi/full/10.1586/ern.12.90

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