The following list of symptoms for Sensory Processing Disorder (SPD) is preliminary and not exhaustive. The general rule for possible symptoms is that they all affect sensory information transmitted through the sensory nervous system. This involves somatic information from the senses, as well as visceral information from the inner organs. Every process can be affected in which an organ has to make an adjustment based on information transmitted through the sensory nervous system.

Patients with SPD likely experience other conditions with symptoms included in SPD, such as chronic fatigue syndrome, fibromyalgia, or ADHD. For SPD to be considered as the underlying cause, at least one symptom from each category must be present. These symptoms must be chronic, not recent, but can be both intermittent or permanently present.

Light neurological symptoms:

• Sensitivity to light, temperature or touch.
• Visual snow: Seeing static like in old tv screens especially when looking at unicolored surfaces.
• Pattern glare: Patterns with sharp contrasts can lead to visual discomfort.
• Palinopsia: Seeing afterimages of brief visual impressions that linger after the stimulus is gone.
• Paresthesia or formication: Tingling like ants or needles on the skin; usually in the legs, but can be everywhere.
• Migraines: Can be silent and only with aura.
• States of temporary confusion in relation to sensory sensitivity or migraine episodes.
• Tinnitus: Ringing, buzzing, hissing, or roaring sounds in the ears.
• Susceptibility to ASMR: Relaxing tingling sensation on specific sounds or touches.
• Buzzing in the head: Sometimes also trembling, vibration or fizzy feeling.
• Derelization: Mental disconnection from own body or mind.
• Depersonalization: Everything feeling unreal, distorted, or dreamlike.

Dysfunctions of the sleep state:

• Delayed sleep rhythm (usually falling asleep at 2-3am).
• Erratic sleep pattern (non-24).
• Waking up when going to bed too early.
• Inability to fall asleep despite fatigue.
• Inability to wake up in the morning.
• No refreshing sleep irrespective the duration.

Dysfunctions of the wake state:

• Post-exertional malaise (PEM).
• Postural orthostatic tachycardia syndrome (POTS).
• Daytime fatigue with no clear cause.
• Episodes with the strong urge to sleep during the day.
• Intolerance for steam sauna.
• Severity of symptoms varies in erratic cycles.

General health problems:

• Intolerance towards certain foods (often histamine).
• Inability to lose weight; prone to gain weight.
• Below average sex drive or libido.
• prone for infections; swollen lymph nodes

Weather sensitivity:

• Seasonal changes in the severety of the symptoms.
• Locational differences in the severety of the symtoms.
• Sensitivity towards humidity, air pressure or temperature.