Appellants' claims against appellees are health care liability claims sounding in negligence. The elements of such claims are (1) a legal duty, (2) a breach of that duty, and (3) damages proximately caused by the breach. Columbia Med. Ctr. Subsidiary, L.P. v. Meier, 198 S.W.3d 408, 414 (Tex. App.--Dallas 2006, pet. denied). The standard of care for a health care provider is what an ordinarily prudent health care provider would do under the same or similar circumstances. Proximate cause encompasses foreseeability and cause in fact. Meier, 198 S.W.3d at 414. Cause in fact is established if the negligent conduct was a substantial factor in bringing about the injuries and, without it, the harm would not have occurred. Id. In a medical-malpractice case, the plaintiff ordinarily must produce expert testimony to establish both the applicable standard of care and proximate causation if those matters are not within the experience of a layperson.