I’m just going to block quote that CX PDF with a few small modifications. That’s why we have an answer to the inevitable noob question of “how does crucifixion kill?”
Respiratory and cardiovascular failure were two of the most likely causes of death in crucified women. The first proposed cause of death, now widely accepted as the main cause, was asphyxiation (LeBec, 1925; Davis, 1965; Maslen and Mitchell, 2006). Over time, breathing required increased effort as muscles became exhausted. The resting position of the woman’s body was such that the arms were outstretched, the knees bent, and the breasts sagged forward. Collectively, these aspects placed the entire weight on her wrists. The tension applied to the pectoral muscles pulled the chest wall and the breasts upward and outward, which decreased the work of inspiration and drastically increased the work of expiration (Furlong, 1952; Eduard et al., 2017).
As vital capacity and expiratory reserve volumes decreased, the woman would have developed functional respiratory acidosis. In order to exhale sufficiently, she would have needed to straighten her knees, flex her elbows, adduct the shoulders, and push her tortured body upward on the nail-impaled upper limbs (Lumpkin, 1978). Over the course of hours to days, large-scale organ failure would have set in, muscles would have weakened, and lactic acid would have accumulated, expediting systemic decompensation (Retief and Cilliers, 2003). The crucified woman would ultimately have been unable to lift her body enough to breathe sufficiently, leading to death by asphyxiation.
Experiments conducted by Mödder (1948), in which healthy medical students were hung by the wrists, revealed signs of decompensation within 12 min as the blood pressure halved, tidal volume decreased by 70%, and pulse pressure doubled. Breathing at this stage, with arms fully extended, was purely diaphrag- matic. When the subjects were allowed to use their legs to lift the torso against gravity, the cardiovascular symptoms improved until the muscles fatigued and the vicious cycle continued.
Some sources mention death due to extraneous fac- tors such as hypovolemia, cardiac arrest, and cardiac tamponade (Retief and Cilliers, 2003; Bergeron, 2012). Extreme dehydration leads to depletion of intracellular and extracellular volume, which decreases cardiac out- put and leads to hypovolemic shock and subsequent organ failure (Gordon and Shapiro, 1975). The same occurs in the event of exsanguination due to major vascular injury or bone fracture. In order to expedite death, executioners could use a hammer to fracture the tibia and fibula, resulting in death due to internal bleeding and hastened respiratory depression (Barbet, 1953; Eduard et al., 2017). Haas (1970) claimed to have found evidence of tibial fracture in the crucified remains found in Israel; however, those findings were deemed inconclusive by Zias and Sekeles (1985).
Cardiac arrest can present with exaggerated vaso- vagal reflexes due to excruciating pain or pleural disruption from a fractured rib (Retief and Cilliers, 2003). Cardiac tamponade, in which serous fluid accumulates within the pericardial sac, is possible following blunt trauma to the chest, which could have been caused by the abovementioned precrucifixion rituals (Retief and Cilliers, 2003). Finally, it is noted that guards would occasionally set a smoldering fire at the base of the woman’s cross to expedite death by suffocation (Schulte, 1983; Edwards et al., 1986).