Luke 22:43-44 and the sweating of blood the resonance of this scripture with modern haematology pertains to the field of blood coagulation where Jesus’ facial blood mingled with sweat and clotted before falling to the ground. We now provide evidence demonstrating the physiological support for this text together with evidence for the symbolic use of blood.
Translation (RSV); And there appeared to him an angel from heaven, strengthening him. And being in an agony he prayed more earnestly, and his sweat became like great drops of blood falling to the ground.
‘Did Jesus literally sweat blood’? The arguments for and against this will now be given. Luke's account of Jesus' agony and sweating blood in the Garden of Gethsemane in the original Greek uses special haematological root words such as thromboi haimatos literally clots of blood--see the underlined text above. The related English words thrombus and thrombin are closely associated with clots of blood in modern haematology. Biblical scholar Richard Lenski (1961:1077) commented on thromboi haimatos: 'As clots, thromboi, means that blood mingled with sweat and thickened the globules so that they fell to the ground in little clots and did not merely stain the skin'.
Victorian Greek scholar Henry Alford (1874, 1:648) observed that the Greek word hosei ('as it were') refers to condition and not comparison:
The intention of the Evangelist seems clearly to convey the idea that the sweat was (not fell like, but was) like drops of blood; —namely, coloured with blood, —for so I understand the hosei, as just distinguishing the drops highly coloured with blood, from pure blood... To suppose that it only fell like drops of blood (why not drops of anything else? And drops of blood from what, and where?) is to nullify the force of the sentence and make the insertion of haimatos not only superfluous but also absurd.
Miller (2004:1) finds Alford's interpretation (albeit Victorian) to be persuasive in that Luke was referring to the great mental anguish of Jesus as being literal and producing actual blood mingled with sweat.
Further evidence supporting a literal interpretation of the above passage comes in modern medicine from the rare examples in the medical literature of where human subjects literally sweated blood. This condition is known as 'haematidrosis' or 'hemohidrosis' (Allen 1967:745-747) and results in the excretion of blood or haemoglobin in the sweat.
Lumpkin (1978) thinks that under great emotional stress, the fragile capillaries in the sweat glands may rupture thus allowing the blood to mix with the sweat. Several cases of stress-related haematidrosis have been reviewed by various authors (see overview by Miller 2004). Holoubek and Holoubek (1996) in a classification by cause of 76 cases of haematidrosis found that 'Acute fear and intense mental contemplation were found to be the most frequent inciting causes’. This evidence from modern medicine seems to accord well with a literal interpretation of actual blood clots mingled with actual sweat.
However many modern scholars consider that the sweat was simply being compared to drops of blood. The modern scholars, notably Ehrman and Plunkett (1983:416), question the authenticity of this.
However, it should be noted that certain of the church fathers chose to include this passage
particularly Irenaeus in his argument against the Docetae. We should also note that whilst these two verses may not be in the original text, they do clearly reflect the first-century tradition (Ehrman and Plunkett p.407-408).
If Jesus experienced haematidrosis, this might be an example of how modern science may help us in our exegesis by supporting a literal interpretation of sweating blood. Ehrman’s concession that the interpretation of the literal sweating of blood by Jesus clearly reflects the first-century tradition irrespective of whether the two verses in question were not in the original draws our attention to the extreme mental and emotional anguish Jesus suffered. This is arguably the key point of the narrative. The clots of blood in the sweat would provide evidence of a physiological resonance and the falling of sweat, as great drops of blood are symbolic of Jesus’ agony and effort.
Based on the above evidence this author believes that Jesus literally sweated blood.
 Quoted by Miller (2004:1).
This extract is from Charles Green- dissertation for the Master's degree , School of Divinity, University of Edinburgh (2016).
Full references can be obtained on request