In Doctor Who, when is the first time it is stated that the Doctor (and all other timelords) have two hearts?

I know that in the old episode 'The Sensorites' the Doctor says something about his heart (singular).

2 Answers 2


The first instance that The Doctor is confirmed as having two hearts is Spearhead from Space, the first story of the Third Doctor, where one of the characters discovers that the Doctor has two hearts.

At the hospital, Doctor Henderson discovers the Doctor's blood supply is different and that he has two hearts.

According to the Heart article from the TARDIS wiki, The Edge of Destruction and The Wheel in Space both make the mistake of saying that the Doctor only has one heart.

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    It's also worth noting that the story immediately before Spearhead from Space; the second doctor's final story "War Games", was the first mention of the Doctor's race being Time Lord. Thus, almost all the information about the doctor's physiology and history in episodes prior to War Games should be taken with a pinch of salt.
    – Nellius
    Jan 19, 2012 at 16:23
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    I'm not sure it was a mistake - or maybe it was just retconned, but I remember reading that some Timelords have only one heart until their 1st regeneration and the Doctor is one of them.
    – Tango
    Jan 19, 2012 at 17:25
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    @TangoOversway That was a retcon added to explain the discrepancy. As mentioned, most of the details about the Time Lords weren't created until after the First and Second Doctor.
    – thedaian
    Jan 19, 2012 at 17:33
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    You can sort of explain away the discrepancy in “The Edge of Destruction” if you squint at it. The Doctor bangs his head on the console, and when Ian checks him, his exact words are “His heart seems all right, and his breathing's quite regular.” At a stretch, it could be a way of saying he has a pulse, which is what Ian was probably looking for. iirc, that’s the line that gets interpreted as meaning he has one heart.
    – alexwlchan
    Jan 30, 2014 at 16:03
  • @alexwlchan - Yes, and Ian isn't a medical expert. Also, in "The Wheel in Space" no verbal reference is made to his heart, it's just that a human doctor looks at his chest with some advanced equipment and doesn't comment on it--though as pointed out here, "We also don't know exactly what the equipment was or how it functioned. An EKG is sophisticated, but wouldn't detect two hearts."
    – Hypnosifl
    Jul 18, 2015 at 10:22

I looked this up because I am watching one of the only stories still around with the Second Doctor, The Dominators.

They just examined Jamie and said one heart, etc. Then the other Dominator not doing the exam asks about examing The Doctor but the first says no, he will have the same. I wonder if they were already thinking two hearts then but just didn't mention it.

lol Haven't finished watching and just got to the part where they find out the natives have two hearts, so maybe not.. who knows.

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