Functional neurological disorder (conversion disorder)

For a lay person:

Functional neurological disorder is a condition in which the nervous system does not work properly even though its structure is not damaged, causing real and often disabling symptoms such as weakness, shaking, seizure-like attacks or trouble walking. The symptoms are genuine and not imagined or faked. It can follow stress, illness or injury, but often there is no clear trigger, and many people improve with the right treatment.

For a trained medical person:

A disorder of nervous system functioning, formerly termed conversion disorder or hysteria, producing motor, sensory or dissociative (non-epileptic) symptoms that are clinically incompatible with recognised structural disease; predisposing factors include prior trauma, other functional or psychiatric conditions and illness or injury. Diagnosis is made positively by a neurologist using clinical signs such as Hoover's sign or video-EEG for attacks, not merely by excluding other conditions. Management begins with a clear explanation of the diagnosis, followed by specialist physiotherapy, occupational therapy and psychological therapy such as CBT.

In Chinese medicine:

Liu and Tseng's textbook gives Chinese herbal formulas for this condition without a full pattern differentiation. Treatment still follows the pattern a patient presents with, not the Western diagnosis alone.

When to get help: Seek emergency care for new sudden weakness, numbness, speech problems or a first seizure, as these need assessment to rule out stroke or epilepsy. Seek help urgently if you have thoughts of self-harm, and do not stop prescribed medication without medical advice.