They are large humanoid creatures, standing tall in height and towering over Henry Townshend. They resemble a feminine monster with grotesquely distorted facial features. They have mottled gray skin with chunks missing from their bodies and wear bloody gray hospital gowns as well. They move very fluidly and lack the twitching movements common to many other monsters. They always wield pipes in their hands, which they use to attack victims. Normally they make low-pitched breathing and growling noises, and when struck, they make grunts that sound very much like belching and burping.
They are large, menacing opponents that attack relentlessly but slowly. They deal large amounts of damage and take an impressive amount of punishment as well. However, they are easily interrupted or avoided and can be defeated without much effort (but plenty of time) by a constant flurry of blows. They often appear in groups of two or more, making it much more difficult to defeat them. The rusty axe is the recommended method of dealing with them. Another method is to use Richard's revolver found in his apartment in the Otherworld, as it is capable of knocking down these enemies in one or two shots.
The Patients may be manifestations of Walter Sullivan's possible aversion to hospitals and the like, finding them terrifying as the Patients themselves are imposing.
At first, the name "patient" implies someone who is unhealthy and being cured by a doctor. However, it seems more likely that Walter views himself as a doctor, and the Patients are literally Walter's patients. It is possible that this is an allegory for his secondary intent of saving the world from their sin in completing the 21 Sacraments. The "Descent of the Holy Mother - The 21 Sacraments" memo proclaims that, after the ritual's completion, "by the Mystery of the 21 Sacraments, the Mother shall be reborn and the Nation of Sin shall be redeemed."
The bloodstains on their hospital gowns make it seem as if they are bleeding from where the uterus should be, suggesting that they are a manifestation of Walter's possible hatred for his biological mother who abandoned him at birth, as he seems to have taken both their lungs and wombs out. They may also symbolize Walter's search for a mother.
They may symbolize Walter's possible hatred and contempt of women in general. This is seen in the Hospital World, where Walter disembowels one. Similar imagery can also be seen in the spiral staircase, such as female mannequins in cages, stabbed in the abdomen, where the uterus is located, with needles or spikes. Another female mannequin can be seen stabbed in the head with scissors and hung by nipples. This type of imagery may also allude to to the 21 Sacraments and the Death Machine, in conjunction with the last needed sacrifice, requiring that the "Mother Reborn" (represented by Eileen Galvin) meet an exceptionally gruesome death. This would mean that rather than him necessarily disliking women, it represents his strong desire to be with his mother again.
The Patient's facial and hair appearance resembles that of Claudia Wolf. This is especially observable during the Hospital World's intro cutscene, where Walter is seen "operating" on one. Much can be speculated about this. It may be theorized that it's simply an easter egg. However, it can be theorized that Walter knew Claudia; perhaps Walter admired Claudia and chose her as his model. It is also possible that Walter dislikes Claudia because she could not fulfill her mission of bringing God into the world; however, Walter's awareness of Claudia's failure is unlikely, given his isolation from the rest of the cult and his preoccupation with Room 302, his Otherworlds, and the locations of his body.
The burping-like sounds may possibly indicate the emission of gases produced from bodily decomposition, specifically from where the lungs and uterus were removed.