Opinion by
Me. Justice Bell,Plaintiff brought an action in trespass for personal injuries resulting from two widely separated accidents. The serious injuries which he suffered on June 14,1952, he alleged, resulted from an accident on March 17, 1951. Plaintiff, on March 17, 1951, entered one of the defendant’s warehouses in order to purchase some siding. Plaintiff tried to pass around the supervisor of defendant’s warehouse, and, because of the inadequacy of light, stepped into a hole in the floor of the warehouse and fell, thereby injuring his left hand and wrist. Although he claims that he suffered constant pain, he lost no time from work and made no claim for any injuries resulting from this accident until January 23, 1953, over months later.
On June 14, 1952 — 15 months after the first accident — while painting the roof of a neighbor’s house, plaintiffs left wrist and hand suddenly gave way and he fell to a concrete floor on the ground level, breaking his right heel and suffering contusions. His leg was in a cast for six weeks. The accident occurred, according to plaintiff, as follows: “I started at nine o’clock in the morning, and by three o’clock in the afternoon X only had about two more square yards to do. To do that roof, I had to move the ladder about five or six times. And to do those two square yards, I had to make one more move. I put the ladder in position, g-ot my stain, and went up and finished the two square *422yards, tried to. I put my left hand against the roof, worked with the right hand, and before I know, my left hand just gave way* collapsed. I fell back to my elbow, and I thought I could stop it from going any further, but I didn’t succeed, and I kept on rolling towards the left.
“I did grab for the ladder with my right hand, and got hold of the ladder, and lifted the ladder from the roof. And through all that commotion, the ladder gave way on the bottom, and out she went, and the ladder and all fell down.”
It was not until seven months after this second accident and twenty-two months after the first accident, that the plaintiff sued the defendant for damages for the injuries which he allegedly sustained in both accidents. Plaintiff contends that the first accident was attributable to the defendant’s negligence and that the second accident resulted from the injury to his wrist which he sustained in the first accident.
Defendant denied that it was responsible for the first or second accident and further denied that the first accident caused the second accident or the injuries received therein. During the course of the trial considerable medical testimony was presented by both litigants and it is this testimony which raises the crucial point in this appeal.
The jury returned a verdict for plaintiff in the amount of $11,000., based almost entirely upon the injuries he suffered in the second accident. Defendant’s motions for judgment n.o.v. and for a new trial were denied by the lower Court.
Defendant is pressing, in this appeal, its motion for a new trial. Defendant contends (1) that legally competent medical testimony was required to establish a *423causal connection between the two accidents and (2) that such testimony was not produced by plaintiff and (3) consequently it is not liable for injuries suffered by plaintiff in the second accident and therefore a new trial should be granted. A review of the medical testimony and the pertinent authorities substantiate defendant’s position.
If plaintiff wished to recover for injuries resulting from the second accident it was incumbent on him— under the facts of this ease — to prove by competent and definite medical testimony that there was a causal relationship between the two accidents. Courts have found it difficult to lay down a precise standard which can fit every case on the question of whether medical testimony is necessary to prove a causal connection between the latest injury and a prior injury. The necessity of medical testimony will depend in each case upon the particular facts of that case including, inter alia, the kind of injury which occurred in each accident, the time interval between the accidents, the plaintiff’s activities between the accidents, and the exact manner in which the last accident occurred.
In Washko v. Ruckno, Inc., 180 Pa. Superior Ct. 608, 121 A. 2d 456, medical evidence was required to prove that a heart attack was produced by heavy work done thirty minutes before. The Court said (page 609) : “It was claimant’s duty to prove that her husband’s death resulted from the alleged over-exertion: Adamehick v. Wyoming Valley Colleries Co., 332 Pa. 401. Where there is no obvious causal relationship * unequivocal medical testimony is necessary to estab*424lish the causal connection: Rich v. Philadelphia Abbatoir Co., 160 Pa. Superior Ct. 200.”
In Fink v. Sheldon Axle & Spring Co., 270 Pa. 476, 113 A. 666, medical testimony was required to connect a paralytic stroke with being struck by a swinging door. Similarly, medical testimony was held necessary where plaintiff contended that pneumonia resulted from a cut in his arm two months previously: Anderson v. Baxter, 285 Pa. 443, 132 A. 358. Medical testimony was likewise held to be necessary where a plaintiff claimed that pneumonia was the result of an accident he had suffered seven weeks earlier: MeCrosson v. P. R. T. Co., 283 Pa. 492, 129 A. 568.
On the other hand, medical testimony was held to be unnecessary in Tabuteau v. London G. & H. Co. Ltd., 351 Pa. 183, 40 A. 2d 396, where plaintiff suffered pain in his groin and a hernia developed immediately after he misstepped on an uneven sidewalk. The Court said (page 186) : “. . . expert testimony is not necessary where death (or injury) is so immediately and directly, or naturally and probably, the result of the accident that the connection between them does not depend solely on the testimony of professional or expert witnesses: Davis v. Davis, 80 Pa. Superior Ct. 343; McCoy v. Spriggs, 102 Pa. Superior Ct. 500, 157 A. 523.
“Plaintiff produced direct and competent evidence which, if believed, clearly established the causal relationship between the accident and the injuries. Plaintiff’s own testimony is sufficient to support the finding of the jury that he suffered an accidental injury within the terms of the policy, resulting in disability.
“In Mohr v. Desimone & Sayers, 110 Pa. Superior Ct. 44, 49, 167 A. 504, the court said: ‘It has frequently been held that where the disability complained of is the natural and probable result of the injuries, the fact-finding body may be permitted to so find, even in the *425entire absence of expert opinion.’ In the instant case the sequence of events strongly indicates a causal connection between the entirely unexpected injury and the continuous disability following it. Plaintiff had been in excellent health, and had done the same work for thirty years before the accident. But immediately after the accident he was disabled by a perfectly obvious injury which a layman could diagnose, and he was unable to work as before. The accident and the injury were so closely connected, and so quickly apparent, that the circumstances themselves justified the submission to the jury: Stracka v. Mosko, 99 Pa. Superior Ct. 463.”
In the instant case, the evidence including the interval of time between accidents and the manner in which the last accident occurred make it obvious that only expert testimony could connect the two accidents. The second accident could have happened from any one of half a dozen different causes. There was no obvious causal relationship between the accident of March 17, 1951 and the accident of June 14, 1952. The last accident could not reasonably be said by a layman— without guessing — to be the natural and probable result of the injuries suffered from the first accident. The second accident did not immediately and directly result from the first accident nor was it the natural and probable result of the first accident which was so closely connected and so readily apparent that a layman could diagnose (except by guessing) the causal connection. In other words, medical testimony was necessary to establish — if it could — the causal connection between the two accidents.
Plaintiff, in order to prove the causal connection between the two accidents, called Dr. Herbert Kaplan, his family physician, and Dr. London. Dr. Kaplan treated the plaintiff after both accidents, but did not *426know, before the present trial, that plaintiff had previously (many years before) broken his left wrist. His pertinent testimony was as follows: “I feel that it is possible and very highly probable that because of the burning sensation and the pain which flew in there, and, understand, I told the man to use his hand, that it is possible he had the same type of burning, tingling, boring pain — . ... In my opinion, the cause of the collapse of the wrist on that day was due to the causalgia-like pain which had been persisting since the day of the [first] injury. If I can simplify it, I will say in my opinion that this could have caused him to slide from the roof.”
Dr. Russell London, the second doctor produced on behalf of the plaintiff, testified relative to the question of causation: “A. In a wrist previously fractured but permitting, according to history, full function over all those years, and then paining consistently from the time of the second episode, with the degenerative changes we have previously mentioned in that wrist, I can conceive that there is pain at the extremes of certain motion, and for an excessive length of time, which could have caused the patient to save his hand suddenly and lost his balance.”
Plaintiff’s medical history revealed that before the first accident he had broken his left wrist and sustained an injury to the radial joint of his left arm and had developed both degenerative arthritic changes and severe hypertension, which of itself may well cause dizziness. Furthermore, he had been painting this roof for six hours; he had moved the heavy ladder about five or six times during that day; and had just moved the ladder immediately before the accident. These important facts were not mentioned by Dr. Kaplan or by Dr. London.
*427Dr. Ellwood S. Myers, who examined plaintiff at defendant’s request, testified, in response to the question of whether the second accident was suffered as a result of the first accident: “A. I would say definitely no. My reason for that is three-fold, if I may explain that. Most unfortunately, this man has, as I have told you, two previous injuries to this wrist. From examination of the X-rays, he could not have, previous to this, a perfectly normally functioning wrist. That goes without doubt because of the presence of arthritic change in the radial head. That would have prevented him, no matter what he says or what anyone says, just by looking at the X-rays, it would have prevented him from bringing that hand perfectly inside normally and give him full function. It could not have helped to. It would also prevent his putting it all the way out, and to a certain extent it would have prevented him getting it up. It may not have hurt him, I won’t argue that. But here is an injury that preceded, and here is another injury that preceded, and on top of that he gets a third injury, tie couldn’t help but have a weak arm, I don’t see how he could help it. But to blame that on an injury that didn’t even injure the bone, and injured the soft tissues, giving him, if you want to term it, a neuralgia or a neuritis, I am afraid I can’t see it.
“As far as his falling off the roof is concerned, I don’t know anything about this, but upon my physical examination, the man has a terrific hypertension. He has 204 blood pressure, systolic, over eight-six. He has very poor eyesight. His eyes, normal eyesight, should be twenty-twenty. His vision is twenty over a hundred. Those two factors, in themselves, certainly must have a bearing. Q. Does hypertension sometimes cause dizziness? A. Yes, it definitely does.”
*428The law in this field is well settled. In Wargo v. Pittsburgh Railways Co., 376 Pa. 168, 101 A. 2d 638, this Court reversed the lower Court and granted a new trial in a case analogous to the one at bar. The Court said: “From the testimony of plaintiff’s physicians it is impossible to do anything but guess as to how much, if any, of plaintiff’s present back condition is due to the present accident instead of to his original back injury and arthritis!”
In Menarde v. Philadelphia Trans. Co., 376 Pa. 497, 103 A. 2d 681, the Court said (page 501) : “Moreover the expert has to testify, not that the condition of claimant might have, or even probably did,* come from the accident, but that in his professional opinion the result in question came from the cause alleged. A less direct expression of opinion falls below the required standard of proof and does not constitute legally competent evidence: Vorbnoff v. Mesta Machine Co. et al., 286 Pa. 199, 206, 133 A. 256; Powell v. Risser, 375 Pa. 60, 68, 69, 99 A. 2d 454; Wargo v. Pittsburgh Railways Company, 376 Pa. 168, 172, 101 A. 2d 638.” See to the same effect: Nestor v. George, 354 Pa. 19, 46 A. 2d 469; Anderson v. Baxter, 285 Pa. 443, 132 A. 358; McCrosson v. Philadelphia Rapid Transit Co., 283 Pa. 492, 129 A. 568; Fink v. Sheldon Axle & Spring Co., 270 Pa. 476, 113 A. 666; Monahan v. Seeds & Durham, 336 Pa. 67, 6 A. 2d 889.
The case at bar is ruled, both on its facts and in principle, by the above mentioned authorities. Dr. Myers positively and unequivocally denied that the injuries suffered in the second accident resulted from the injuries incurred in the first accident. Dr. London, plaintiff’s witness, testified that the injuries received in the first accident “could have” caused the second *429accident. Dr. Kaplan’s opinion was qualified by Ms testimony that tbe first accident “could have caused” or that “it is possible and very highly probable” that it caused the second accident; he also testified “in my opinion this could have caused him to slide from the roof.” None of plaintiff’s medical testimony was sufficient to meet the standard of proof required by the cases hereinabove cited.
In Nikisher v. Benninger, 377 Pa. 564, 105 A. 2d 281 and Bender v. Welsh, 344 Pa. 392, 25 A. 2d 182, which are relied upon by the lower Court, medical testimony was not required to establish the causal relationship between the two accidents and the cases are on their facts clearly distinguishable.
It is unnecessary to discuss whether a new trial should be granted because the verdict was against the evidence or against the weight of the evidence. Cf. Wargo v. Pittsburgh Railways Co., 376 Pa., supra; Duffy v. The Monongahela Connecting R. R. Co., 371 Pa. 361, 89 A. 2d 804; Dupont v. Gallagher, 360 Pa. 419, 62 A. 2d 28; King v. Equitable Gas Co., 307 Pa. 287, 161 A. 65; Smith v. Allegheny County, 377 Pa. 365, 105 A. 2d 137.
The judgment of the lower Court is reversed and a new trial is granted.
Italics throughout, ours.
Cf. Gill v. Wentz, 365 Pa. 32, 73 A. 2d 403; Saylor v. Greenville Steel Gar Co., 157 Pa. Superior Ct. 331, 43 A. 2d 633; McCoy v. Spriggs, 102 Pa. Superior Ct. 500, 157 A. 523; Stracka v. Mosko, 99 Pa. Superior Ct. 483; Utzman v. Penna. Rubber Co., 98 Pa. Superior Ct. 483.
Italics throughout, ours-