Stress injury, meaning emotional concerns such as anxiety, annoyance, disappointment, distress, fear, frustration, loss of peace of mind, upset, among other things, are genuine sufferings despite the difficulty of precise measurement. Additionally troublesome in measuring stress injury is that susceptibility to stress injury can vary. There are people with 'thin skin' who may be more emotionally effected by wrongdoing than other people.
Traditionally, judges were hesitant to provide awards for stress injury arising from tortious conduct or breach of contract, especially where medical evidence in the form of a psychological diagnosis was lacking. This hestitation further upset litigants already upset by the issues that brought the litigation about. Litigants who were wronged often feel twice shorted - first by the wrongful conduct that caused the litigation and then by the justice system for failing to compensate for the stress injury resulting from the wrongful conduct.
Especially in Small Claims Court matters, it appears that judges prefer to provide awards strictly for actual damages as precisely measurable sums and to avoid wading into the guessing game of how severe was the stress and how much is compensation for that stress worth. Small Claims Court judges are often unwilling to permit advocates, whether lawyers or paralegals, with the opportunity to argue for general damages due to stress injury. The exception it seems is where Small Claims Court judges are willing to provide awards in matters of intentional wrongdoing, especially those wrongs where the Defendant intended to cause upset; however, for unintentional matters of negligence, especially negligent contractual performance, rarely - or at least inconsistently, are general damages awarded for stress injury.
The Law, tort
Recently, the Supreme Court addressed the issues of stress injury by clarifying that general damages for mental distress do not need medical support via psychiatric evidence and that general damages for mental distress are appropriate where the distress is, "serious and prolonged" and rises above "the ordinary annoyances, anxieties and fears that people living in society routinely" experience. The following paragraphs from the two cited cases when referenced together should demonstrate that where stress occurs as a result of tortious conduct, and where the stress is beyond that which is regular and routine to ordinary life, the lower courts are bound to consider awards for general damages:
Saadati v. Moorhead,  1 S.C.R. 543
 This Court has, however, never required claimants to show a recognizable psychiatric illness as a precondition to recovery for mental injury. Nor, in my view, would it be desirable for it to do so now. Just as recovery for physical injury is not, as a matter of law, conditioned upon a claimant adducing expert diagnostic evidence in support, recovery for mental injury does not require proof of a recognizable psychiatric illness. This and other mechanisms by which some courts have historically sought to control recovery for mental injury are, in my respectful view, premised upon dubious perceptions of psychiatry and of mental illness in general, which Canadian tort law should repudiate. Further, the elements of the cause of action of negligence, together with the threshold stated by this Court in Mustapha v. Culligan of Canada Ltd., 2008 SCC 27 (CanLII),  2 S.C.R. 114, at para. 9, for proving mental injury, furnish a sufficiently robust array of protections against unworthy claims. I therefore conclude that a finding of legally compensable mental injury need not rest, in whole or in part, on the claimant proving a recognized psychiatric illness. ...
Mustapha v. Culligan of Canada Ltd.,  2 S.C.R. 114
 This said, psychological disturbance that rises to the level of personal injury must be distinguished from psychological upset. Personal injury at law connotes serious trauma or illness: see Hinz v. Berry,  2 Q.B. 40 (C.A.), at p. 42; Page v. Smith, at p. 189; Linden and Feldthusen, at pp. 425-27. The law does not recognize upset, disgust, anxiety, agitation or other mental states that fall short of injury. I would not purport to define compensable injury exhaustively, except to say that it must be serious and prolonged and rise above the ordinary annoyances, anxieties and fears that people living in society routinely, if sometimes reluctantly, accept. The need to accept such upsets rather than seek redress in tort is what I take the Court of Appeal to be expressing in its quote from Vanek v. Great Atlantic & Pacific Co. of Canada (1999), 1999 CanLII 2863 (ON CA), 48 O.R. (3d) 228 (C.A.): “Life goes on” (para. 60). Quite simply, minor and transient upsets do not constitute personal injury, and hence do not amount to damage.
The Law, contracts
The issue of general damages resulting from stress injury occurring from a breach of contract was also addressed by the Supreme Court and it was deemed that, in following the Hadley v. Baxendale principle, where the contract bargain contained an emotional benefit element, which was reasonably contemplated by the parties to the contract at the time of contract formation, the loss of the emotional benefit should result in compensation as a general damage.
Fidler v. Sun Life Assurance Co. of Canada,  2 S.C.R. 3
 We conclude that damages for mental distress for breach of contract may, in appropriate cases, be awarded as an application of the principle in Hadley v. Baxendale: see Vorvis. The court should ask “what did the contract promise?” and provide compensation for those promises. The aim of compensatory damages is to restore the wronged party to the position he or she would have been in had the contract not been broken. As the Privy Council stated in Wertheim v. Chicoutimi Pulp Co.,  A.C. 301, at p. 307: “the party complaining should, so far as it can be done by money, be placed in the same position as he would have been in if the contract had been performed”. The measure of these damages is, of course, subject to remoteness principles. There is no reason why this should not include damages for mental distress, where such damages were in the reasonable contemplation of the parties at the time the contract was made. This conclusion follows from the basic principle of compensatory contractual damages: that the parties are to be restored to the position they contracted for, whether tangible or intangible. The law’s task is simply to provide the benefits contracted for, whatever their nature, if they were in the reasonable contemplation of the parties.
 It does not follow, however, that all mental distress associated with a breach of contract is compensable. In normal commercial contracts, the likelihood of a breach of contract causing mental distress is not ordinarily within the reasonable contemplation of the parties. It is not unusual that a breach of contract will leave the wronged party feeling frustrated or angry. The law does not award damages for such incidental frustration. The matter is otherwise, however, when the parties enter into a contract, an object of which is to secure a particular psychological benefit. In such a case, damages arising from such mental distress should in principle be recoverable where they are established on the evidence and shown to have been within the reasonable contemplation of the parties at the time the contract was made. The basic principles of contract damages do not cease to operate merely because what is promised is an intangible, like mental security.
Guessing at Quantum
Where general damages for stress injury, among other things, are appropriate, the difficulty in determining an award is an improper reason to avoid attempt to provide an award. In such cases where calculation becomes impossible or difficult, such as the reasonable compensation as a 'value for stress', courts will often simply need to guess.
TMS Lighting Ltd. v. KJS Transport Inc., 2014 ONCA 1
 The quantification of damages occasioned by a proven loss is often a difficult task. In many cases, while loss is established, the evidence affords little support for a precise or reliable assessment of damages arising from the loss. For this reason, as Finlayson J.A. noted in Goldfarb, at para. 75, a trial judge confronted with a meagre evidentiary record on damages may be required to resort to educated “guess work”.
Wood v. Grand Valley Railway Co., 51 S.C.R. 283, 1915 CanLII 4 (S.C.C.)
It was clearly impossible under the facts of that case to estimate with anything approaching to mathematical accuracy the damages sustained by the plaintiffs, but it seems to me to be clearly laid down there by the learned judges that such an impossibility cannot “relieve the wrongdoer of the necessity of paying damages for his breach of contract” and that on the other hand the tribunal to estimate them whether jury or judge must under such circumstances do “the best it can” and its conclusion will not be set aside even if the amount of the verdict is a matter of guess work.
With the above principles establishing guidance for the lower courts, it is hoped that general damage awards for stress injury will occur more regularly so to provide wronged litigants with a judicial result that duly attempts to 'make victims truly whole'.