In McLoughlin v. O'Brian, Justice Wilberforce
"... recognisable and severe physical damage to the human body and system may be caused by the impact, through the senses, of external events on the mind."
Nervous shock is often pleaded in a personal injury case for where the plaintiff says that she or he was exposed to horrible carnage or the death of a loved one such that they suffered nervous shock and they seek to recover damages for that from the tort-feasor.
At ¶12 of Rhodes v C.N.R., Justice Maczko wrote:
"Historically a plaintiff could only recover for nervous shock where he or she actually witnessed an event in which a loved one was killed or injured and, as a result of that observation, suffered a medically diagnosed mental illness. This illness came to be known as nervous shock. Later the law expanded to permit recovery in situations where the plaintiff merely apprehended an injury to him or herself or a loved one and, still later, recovery was available where the illness resulted from seeing the aftermath of an accident, i.e., coming upon the scene shortly after a close relative was injured or killed and seeing the results."
In Hinz, Lord Denning wrote:
"In English law no damages are awarded for grief or sorrow caused by a person's death. No damages are to be given for the worry about the children, or for the financial strain or stress, or the difficulties of adjusting to a new life.
"Damages are, however, recoverable for nervous shock or, to put it in medical terms, for any recognisable psychiatric illness caused by the breach of duty by the defendant."
Traditionally, the courts have been reluctant to grant damages for nervous shock in negligence cases. As Justice Wilberforce had mused in McLoughlin, op. cit., this could "lead to a proliferation of claims, and possibly fraudulent claims".
In Dixon v Nova Scotia, Justice Chipman of the Nova Scotia Court of Appeal remarked:
"Nervous shock is not so much a medical diagnosis, but rather a diagnosis at law or a legal label that has been hung on types of mental injury which courts have been prepared to recognize as worthy of recovery of damages.
"While the limits of liability have, from time to time varied, mere grief and sorrow have been universely excluded."
Similarly, this, from Justice Morden in Duwyn v. Kaprielian:
"The law is relatively clear that the kind of nervous shock for which recovery may be had involves something more than general emotional upset."
- Duwyn v. Kaprielian, 94 D.L.R. (3d) 424 (Ontario Supreme Court, Court of Appeal, 1978)
- Hinz v. Berry  2 Q.B. 40
- McLoughlin v. O'Brian, (1982), 2 All E.R. 298
- Rhodes v Canadian National Railway, 49 C.C.L.T. 64 (1989)