A “FND flare up” usually means a temporary period where symptoms of Functional Neurological Disorder suddenly get worse or more intense than usual.

Quick Scoop: What FND Flare Up Means

In FND, symptoms can wax and wane – they may improve for a while, then suddenly return or get stronger again.

A “flare up” is that spike or bad patch where things feel more severe or harder to manage than your recent baseline.

Common examples people describe include:

  • Stronger limb weakness or difficulty walking.
  • More frequent or intense tremors, jerks, or spasms.
  • Increase in non-epileptic seizures or blackout-type episodes.
  • Worsening fatigue, brain fog, or sensory overload (lights, sounds, crowds feel unbearable).

These episodes can last from minutes to days (sometimes longer), and then often settle back toward your usual level.

What Can Trigger a Flare Up?

People with FND often notice patterns or triggers, even if flare ups can feel random.

Typical triggers include:

  • Stress (emotional stress, conflict, major life changes).
  • Physical overdoing it (too much activity, not pacing, lack of rest).
  • Fatigue or poor sleep.
  • Sensory overload (noise, bright lights, busy places).
  • Illness, pain, or other health issues.
  • Changes in routine or unexpected events.

Sometimes there’s no clear trigger, and that doesn’t mean you did anything wrong.

How People Talk About It Online

On FND forums and Reddit, you’ll see people say things like:

“I’m in a bad FND flare up – my seizures and weakness have gone through the roof.”

They often swap tips about:

  • Pacing and rest days.
  • Grounding/breathing techniques.
  • Reducing sensory overload (quiet room, dim lights).
  • Having a “flare plan” (who to contact, meds as advised by doctor, safe space).

When to Worry / See a Doctor

Even if you know you have FND, new or very different symptoms should be checked out, because not everything is automatically “just FND.”

You should seek medical advice urgently if:

  • You have new symptoms you’ve never had before.
  • Symptoms change suddenly in a worrying way (for example, chest pain, new severe headache, trouble speaking, or signs of stroke).
  • You feel unsafe because of seizures, falls, or confusion.

Bottom line: “FND flare up” = a temporary worsening of functional neurological symptoms, often linked to stress, fatigue, or overload, that eventually settles back toward your usual level.

Information gathered from public forums or data available on the internet and portrayed here.