[4][1] According to literature, the condition is caused by violent shaking with or without blunt impact that can lead to long-term health consequences for infants or children.

[1] If there are concerning findings on the CT scan, a full work-up for child abuse often occurs, including an eye exam and skeletal survey.

[26] The type of retinal bleeds are often believed to be particularly characteristic of this condition, making the finding useful in establishing the diagnosis,[27] although again such patterns are not found when shaking is independently witnessed,[28] and is almost certainly due to selection bias.

[30] Infants may display irritability, failure to thrive, alterations in eating patterns, lethargy, vomiting, seizures, bulging or tense fontanelles (the soft spots on a baby's head), increased size of the head, altered breathing, and dilated pupils, although all these clinical findings are generic and are known to have a range of causes, with shaking certainly not the most common cause of any of them.

[37][38][39][40] The incidence of shaken baby syndrome is unknown due to difficulty in diagnosis, which may be caused by lack of centralized reporting system, absent signs of maltreatment, unclear presentation, and acute head trauma being classified under chronic neglect.

[41] Common risk factors for shaken baby syndrome include perceived excessive crying, behavioral health problems, domestic violence history, frustration intolerance, lack of childcare experience, young infant age, young maternal age, multiple births, having a male infant, full-time working, postpartum depression, single parent families and economic adversity.

[36] Substance abuse and emotional stress, resulting for example from low socioeconomic status or family instability, are other risk factors for aggression and impulsiveness in caregivers.

[52] Evidence indicates early crying pattern as the common trigger for SBS, and it results from a failure in what is usually a normal interaction between infants and caregivers.

[56] The association between traumatic shaking, subdural hematoma and retinal hemorrhages was described in 1972 and referred to as whiplash shaken infant syndrome.

[72] While the findings of SBS are complex and many,[73] they are often incorrectly referred to as a "triad" for legal proceedings; distilled down to retinal hemorrhages, subdural hematomas, and encephalopathy.

[36] Examination by an experienced ophthalmologist is critical in diagnosing shaken baby syndrome, as particular forms of ocular bleeding are strongly associated with AHT.

[80] The US Centers for Disease Control and Prevention identifies SBS as "an injury to the skull or intracranial contents of an infant or young child (< 5 years of age) due to inflicted blunt impact and/or violent shaking".

[85][86][87] This contested hypothesis is based upon a speculated marginal, near scorbutic condition or lack of essential nutrient(s) repletion and a potential elevated histamine level.

"[88] The proponents of such hypotheses often question the adequacy of nutrient tissue levels, especially vitamin C,[89][90] for those children currently or recently ill, bacterial infections, those with higher individual requirements, those with environmental challenges (e.g. allergies), and perhaps transient vaccination-related stresses.

Infants that are vitamin D deficient during gestation or experience physical impact during delivery may present with a fracture commonly seen in SBS cases.

Educating expecting parents about how to soothe an inconsolable child, as well as the dangers of physical impact to an infant, may reduce rates of SBS.

[101] The association of diagnosed SBS with deliberate assault is a matter of legal and medical contention, with conflicting opinions as to whether one necessarily implies the other.

One of the main contentions is that many medical definitions create a biased picture of the defendants, marking them as the aggressor and implicitly providing a guilty verdict.

[13] A 2023 academic review by Squier states: "There is insufficient scientific evidence to assume that an infant with the triad of subdural haemorrhage (SDH), retinal haemorrhage, and encephalopathy must have been shaken", and that "research has shown the triad is not sufficient to infer shaking or abuse and the shaking hypothesis does not meet the standards of evidence based medicine.

This debate arises from the difficulty of diagnosing this condition as well as the possibility of non-abuse related causes, such as neglect, an unintentional accident, or even the trauma of birth.

This is problematic since in many states, such legal sentencing is typically rendered by multidisciplinary child-abuse-prevention teams (physicians, social workers, and law enforcement).

[108] The President's Council of Advisers on Science and Technology (PCAST) noted in its September 2016 report that there are concerns regarding the scientific validity of forensic evidence of abusive head trauma that "require urgent attention".

[112] The court found that the classic triad of retinal bleeding, subdural hematoma, and acute encephalopathy are not 100% diagnostic of SBS and that clinical history is also important.

"[113] The court did not believe the "unified hypothesis", proposed by British physician J. F. Geddes and colleagues, as an alternative mechanism for the subdural and retinal bleeding found in suspected cases of SBS.

[112] The court reported that "the unified hypothesis [could] no longer be regarded as a credible or alternative cause of the triad of injuries": subdural haemorrhage, retinal bleeding and encephalopathy due to hypoxemia (low blood oxygen) found in suspected SBS.

Specifically, the appeals court found that "Edmunds presented evidence that was not discovered until after her conviction, in the form of expert medical testimony, that a significant and legitimate debate in the medical community has developed in the past ten years over whether infants can be fatally injured through shaking alone, whether an infant may suffer head trauma and yet experience a significant lucid interval prior to death, and whether other causes may mimic the symptoms traditionally viewed as indicating shaken baby or shaken impact syndrome.

"[114][115] In 2012, Norman Guthkelch, the neurosurgeon often credited with "discovering" the diagnosis of SBS,[116] published an article "after 40 years of consideration," which is harshly critical of shaken baby prosecutions based solely on the triad of injuries.

[116] In March 2016, Waney Squier, a paediatric neuropathologist who has served as an expert witness in many shaken baby trials, was struck off the medical register.

[124] As her case was heard by the High Court of England and Wales in October 2016, an open letter to the British Medical Journal questioning the decision to strike off Squier, was signed by 350 doctors, scientists, and attorneys.

[125] On 3 November 2016, the court published a judgment which concluded that "the determination of the MPT [Medical Practitioners Tribunal] is in many significant respects flawed".