Promoters of this suicide method recommend it to terminally ill patients. However, across the world, most people who use suicide bags are physically healthy. Instead of having incurable cancer or other life-threatening physical diseases, most of the users have psychiatric disorders or substance abuse problems that might possibly be addressed through medical and psychological treatment. The demographics of its users varies; in one survey, the method had been used mostly by middle-aged adults in failing health, who were attracted to the relative nonviolence of the method.

This suicide method is also typically used by younger or middle-aged adults, rather than by older adults. In the US, it is more commonly chosen by non-Hispanic white males than by women or people of other races.

Suicides using bags or masks and gases are well documented in the literature.

Suicide bags have been used with gases other than inert gases, with varying outcomes. Examples of other gases are propane-butane and natural gas.

Suicides using a suicide bag and an inert gas produce no characteristic post-mortem macroscopic or microscopic findings. Forensic death investigations of cause and manner of death may be very difficult when people commit suicide in this manner, especially if the apparatus (such as the bag, tank, or tube) is removed by someone after the death. Petechiae, which are often considered a marker of asphyxia, are present in only a small minority of cases (3%). Frost reported that of the two cases he studied that featured death from inert gas asphyxiation using a suicide bag, one had "bilateral eyelid petechiae and large amounts of gastric content in the airways and that these findings challenge the assumption that death by this method is painless and without air hunger, as asserted in "Final Exit"." A review study by Ely and Hirsch (2000) concludes that conjunctival and facial petechiae are the product of purely mechanical vascular phenomena, unrelated to asphyxia or hypoxia, and do not occur unless ligatures were also found around the neck. The authors wrote,

There are also documented cases of suicide attempts using the suicide bag that failed. A case report study in 2015 discussed the risks associated with failed attempts using this method. The authors wrote, "If the process is interrupted by someone, there is no gas or the tube slips out of the bag, there is a high risk of severe hypoxia of the central nervous system."

Breastfeeding is associated with a lower risk of SIDS. It is not clear if co-sleeping among mothers who breastfeed without any other risk factors increased SIDS risk.

SIDS rates decrease with increasing maternal age, with teenage mothers at greatest risk. Delayed or inadequate prenatal care also increases risk. Low birth weight is a significant risk factor. In the United States from 1995 to 1998, the SIDS death rate for infants weighing 1000–1499 g was 2.89/1000, while for a birth weight of 3500–3999 g, it was only 0.51/1000. Premature birth increases the risk of SIDS death roughly fourfold. From 1995 to 1998, the U.S. SIDS rate for births at 37–39 weeks of gestation was 0.73/1000, while the SIDS rate for births at 28–31 weeks of gestation was 2.39/1000.

Anemia has also been linked to SIDS (note, however, that per item 6 in the list of epidemiologic characteristics below, extent of anemia cannot be evaluated at autopsy because an infant's total hemoglobin can only be measured during life.). SIDS incidence rises from zero at birth, is highest from two to four months of age, and declines toward zero after the infant's first year. Baby boys have a ~50% higher risk of SIDS than girls.

Tube dependency develops in children who have the physical ability to ingest and digest food, but failed to be weaned off their temporary intended tube by traditional means and resist/refuse or cannot make the transition to natural oral feeding. It occurs after the phase of critical medical treatment and interventions when the child is expected to resume or start oral intake.

The medical reasons affecting oral explorative behavior, appetite, sucking and swallowing coordination are diverse, including extreme prematurity, neonatal or postnatal operations, intensive care, parenteral feeding, respiratory support and many more.

Many children are tube-fed during the critical age and the stage of developing oral skills. They may have neuromuscular and sensory conditions requiring physio-occupational and speech and language therapy before becoming ready for learning to eat.

The condition also has psychological and social causes. Children who have experienced oral trauma or have been exposed to medicines with bad flavors may become reluctant to repeat oral experiences.

Many children have been on the receiving end of well-intended encouragement and intrusive feeding attempts or even forced feeding, resulting in growing refusal and oppositional behavior. As the phenomenon of tube dependency is hardly recognized as a problem or functional disorder, there is no scientific data on the issue of incidence or risk of development nor epidemiology in countries with a high standard of neonatal medicine and surgery.

There are positive and negative consequences of tube feeding. It is important to wean the child as soon as possible. The longer a child will be tube fed the higher the risk of becoming tube dependent.

Positive consequences:

- establishing life-supporting functions

- improving quality of life after severe medical conditions

- simple control of food intake and positive effect on growth

Negative consequences:

- excessive vomiting, retching and gagging

- reflux diseases, dislocations of feeding tubes, skin irritationss and skin inflammations

- reduced development of oral autonomy, lack of learning to eat autonomously

- impairment in speech, social and motor development

- active food refusal, oral hypersensitivity, food phobia

- strong defense against any contact with fluids, pureed and solid food

- interactive problems and burden to the family, social and financial stress

Situations that can cause asphyxia include but are not limited to: the constriction or obstruction of airways, such as from asthma, laryngospasm, or simple blockage from the presence of foreign materials; from being in environments where oxygen is not readily accessible: such as underwater, in a low oxygen atmosphere, or in a vacuum; environments where sufficiently oxygenated air is present, but cannot be adequately breathed because of air contamination such as excessive smoke.

Other causes of oxygen deficiency include

but are not limited to:

- Acute respiratory distress syndrome

- Carbon monoxide inhalation, such as that from a car exhaust and the smoke's emission from a lighted cigarette: carbon monoxide has a higher affinity than oxygen to the hemoglobin in the blood's red blood corpuscles, bonding with it tenaciously, and, in the process, displacing oxygen and preventing the blood from transporting oxygen around the body

- Contact with certain chemicals, including pulmonary agents (such as phosgene) and blood agents (such as hydrogen cyanide)

- Drowning

- Drug overdose

- Exposure to extreme low pressure or vacuum to the pattern (see space exposure)

- Hanging, specifically suspension or short drop hanging

- Self-induced hypocapnia by hyperventilation, as in shallow water or deep water blackout and the choking game

- Inert gas asphyxiation

- Congenital central hypoventilation syndrome, or primary alveolar hypoventilation, a disorder of the autonomic nervous system in which a patient must consciously breathe; although it is often said that persons with this disease will die if they fall asleep, this is not usually the case

- Respiratory diseases

- Sleep apnea

- A seizure which stops breathing activity

- Strangling

- Breaking the wind pipe.

- Prolonged exposure to chlorine gas

Perinatal asphyxia is the medical condition resulting from deprivation of oxygen (hypoxia) to a newborn infant long enough to cause apparent harm. It results most commonly from a drop in maternal blood pressure or interference during delivery with blood flow to the infant's brain. This can occur as a result of inadequate circulation or perfusion, impaired respiratory effort, or inadequate ventilation. There has long been a scientific debate over whether newborn infants with asphyxia should be resuscitated with 100% oxygen or normal air. It has been demonstrated that high concentrations of oxygen lead to generation of oxygen free radicals, which have a role in reperfusion injury after asphyxia. Research by Ola Didrik Saugstad and others led to new international guidelines on newborn resuscitation in 2010, recommending the use of normal air instead of 100% oxygen.

The Gururumba tribe believes this syndrome is caused by being bitten by the spirit of a relative that has recently died. "They believe that this releases impulses suppressed by society and civilizations." "There are several reports from Papua New Guinea that the ingestion of various parts of plants or fungi has produced "Wild-Man" syndrome." Among these are reports of eating certain leaves, bark, certain fruit, and certain fungi There is now increasing evidence that some forms of Wild Pig Syndrome is caused by nicotine poisoning from eating green tobacco leaves. Evidence for this can be seen when comparing the physical symptoms of this condition with Wild Pig Syndrome.

The wild man syndrome also known as wild pig syndrome is a culture-bound syndrome that affects the mental health of New Guinean males in which they become hyperactive, clumsy, kleptomaniacal, and conveniently amnesic." It is known in various languages of New Guinea as "guria", "longlong", or "lulu".

"Wild-pig syndrome is a socially constructed disorder with an emotion classification of the Gururumba tribe. The illness is characterized by involuntary antisocial behavior, followed by situational amnesia and the resumption of normal life. After looting neighbors’ homes, the tribesman (usually a recently married male) ventures into the forest for several days, returning without the stolen articles. Wild-pig attacks seem to occur when a man is unable to meet his financial obligations. Those who have undergone the episodes later receive special consideration from creditors. The Gururumba people insist the illness is transmitted by the ghosts of recently deceased tribe members."

Wild pig syndrome is limited by age and sex. It only occurs in males and only men who are 25 to 35 years of age. The syndrome is treated as a disease. The behavior is an action; however, it is not acknowledged as such by society or the individual that is experiencing the condition.

Diving animals such as mink and burrowing animals, such as rodents and rats, are sensitive to low-oxygen atmospheres and (unlike humans) will avoid them, making purely hypoxic techniques possibly inhumane for them. For this reason, the use of inert gas (hypoxic) atmospheres (without CO) for euthanasia, is also species-specific.

The Frontier Middle School shooting was a school shooting that occurred on February 2, 1996, at Frontier Middle School in Moses Lake, Washington, United States. The gunman, 14-year-old Barry Dale Loukaitis (born February 26, 1981), killed his algebra teacher and two students, and held his classmates hostage for over an hour before a gym coach subdued Loukaitis.

When humans breathe in an asphyxiant gas, such as pure nitrogen, helium, neon, argon, sulfur hexafluoride, methane, or any other physiologically inert gas(es), they exhale carbon dioxide without re-supplying oxygen. Physiologically inert gases (those that have no toxic effect, but merely dilute oxygen) are generally free of odor and taste. As such, the human subject detects little abnormal sensation as the oxygen level falls. This leads to asphyxiation (death from lack of oxygen) without the painful and traumatic feeling of suffocation (the hypercapnic alarm response, which in humans arises mostly from carbon dioxide levels rising), or the side effects of poisoning. In scuba diving rebreather accidents, there is often little sensation but euphoria—however, a slow decrease in oxygen breathing gas content has effects which are quite variable. By contrast, suddenly breathing pure inert gas causes oxygen levels in the blood to fall precipitously, and may lead to unconsciousness in only a few breaths, with no symptoms at all.

Some animal species are better equipped than humans to detect hypoxia, and these species are more uncomfortable in low-oxygen environments that result from inert gas exposure.

In a study comparing the central nervous depression due to supra-therapeutic doses of Triazolam (Benzodiazepine), Pentobarbital (Barbiturate) and GHB it appeared as if GHB had the strongest dose-effect function. Since, GHB had a high correlation between its dose and its central nervous system depression it has a high risk of accidental overdose. In the case of accidental overdose of GHB, patients could become drowsy, fall asleep and may enter a coma. Although GHB had higher sedative effects at high doses as compared to Triazolam and Pentobarbital, it had less amnestic effects as compared to Triazolam and Pentobarbital. Arousal of subjects in the GHB group sometimes even required a painful stimulus; this was not seen in the Triazolam or the Pentobarbital group. Fortunately, during this heavy sedation with GHB the subjects maintained normal respiration and blood pressure. This is often not the case with opioids as they will cause respiratory depression.

Poena cullei (from Latin 'penalty of the sack') under Roman law was a type of death penalty imposed on a subject who had been found guilty of parricide. The punishment consisted of being sewn up in a leather sack, sometimes with an assortment of live animals, and then being thrown into water. The punishment may have varied widely in its frequency and precise form during the Roman period. For example, the earliest fully documented case is from ca. 100 BCE, although scholars think the punishment may have developed about a century earlier (earlier than that, murderers, including parricides, would be handed over to the aggrieved family for punishment, rather than punishment being enacted by Roman state officials). Inclusion of live animals in the sack is only documented from Early Imperial times, and at the beginning, only snakes are mentioned. At the time of Emperor Hadrian (2nd century CE), the most well known form of the punishment was documented, where a cock, a dog, a monkey and a viper were inserted in the sack. However, at the time of Hadrian "poena cullei" was made into an optional form of punishment for parricides (the alternate being thrown to the beasts in the arena). During the 3rd century CE up to the accession of Emperor Constantine, "poena cullei" fell out of use; Constantine revived it, now with only serpents to be added in the sack. Well over 200 years later, Emperor Justinian reinstituted the punishment with the four animals, and "poena cullei" remained the statutory penalty for parricides within Byzantine law for the next 400 years, when it was replaced with the punishment for parricides to be burnt alive instead.

"Poena cullei" gained a revival of sorts in late medieval and early modern Germany, with late cases of being drowned in a sack along with live animals being documented from Saxony in the first half of the 18th century.

CNS depression is generally caused by the use of depressant drugs such as ethanol, opioids, barbiturates, benzodiazepines, general anesthetics, and anticonvulsants such as pregabalin used to treat epilepsy.

Drug overdose is often caused by combining two or more depressant drugs, although overdose is certainly possible by consuming a large dose of one depressant drug. CNS depression can also be caused by the accidental or intentional inhalation or ingestion of certain volatile chemicals such as Butanone (contained in Plastic Cement) or Isopropyl Alcohol. Other causes of CNS depression are metabolic disturbances such as hypoglycaemia.

Hiccups may be triggered by a number of common human conditions. In rare cases, they can be a sign of serious medical problems.

A recent explanation by Howes in 2012 suggests that hiccups may have evolved along with other reflexes developed in mammals that allow them to coordinate suckling milk and breathing. Hiccups are only found in mammals, and are most common in infants, becoming rarer as mammals age. This may suggest that they evolved to allow air trapped in the stomach of suckling infants to escape, allowing more milk to be ingested.

The hypothesis suggests that the air bubble in the stomach stimulates the sensory limb of the reflex at receptors in the stomach, esophagus and along the diaphragm. This triggers the hiccup, which creates suction in the chest, pulling air from the stomach up and out through the mouth, effectively burping the animal.

This theory is supported by the strong tendency for infants to get hiccups, the component of the reflex that suppresses peristalsis in the esophagus, and the existence of hiccups only in milk-drinking mammals.

A person can cause frostbite by accidental prolonged contact, using an aerosol on one place for too long. This is often done with deodorants, but other products such as asthma inhalers are also common causes of injury. Injuries are especially common with younger children who "try it out" not knowing all the possible dermatological effects. In rarer cases aerosol burns are reported to have been caused by air fresheners and other compressed aerosol canisters exploding.

Fluorinated hydrocarbon (fluorocarbon) aerosol propellants can be abused, as with solvents. A common form is huffing as a means of intoxication. When inhaled, aerosols can cause the same frostbite as on other parts of the body. The National Institute on Drug Abuse (NIDA) has published various resources on the internet warning of the effects of this abuse, including content especially for teenagers and young people in apparent response to the increase in incidents in this age group.

Some aerosol burns are intentionally self-inflicted, the reasons being emotional/psychological. Household aerosol products such as air fresheners and deodorants can be a convenient, easily available means to satisfy the compulsions.

Hyperventilation syndrome is believed to be caused by psychological factors and by definition has no organic cause. It is one cause of hyperventilation with others including infection, blood loss, heart attack, hypocapnia or alkalosis due to chemical imbalances, decreased cerebral blood flow, and increased nerve sensitivity.

In one study, one third of patients with HVS had "subtle but definite lung disease" that prompted them to breathe too frequently or too deeply.

Many people with panic disorder or agoraphobia will experience HVS. However, most people with HVS do not have these disorders.

The original traditional treatment of breathing into a paper bag to control psychologically based hyperventilation syndrome (which is now almost universally known and often shown in movies and TV dramas) was invented by New York City physician (later radiologist), Alexander Winter, M.D. [1908-1978], based on his experiences in the U.S. Army Medical Corps during World War II and published in the Journal of the American Medical Association in 1951. Because other medical conditions can be confused with hyperventilation, namely asthma and heart attacks, most medical studies advise against using a paper bag since these conditions worsen when CO levels increase.

Foreign body aspiration occurs when a foreign body enters the airways and causes choking. A foreign body in the bronchi usually causes a cough.

Increased water intake may also help in acclimatization to replace the fluids lost through heavier breathing in the thin, dry air found at altitude, although consuming excessive quantities ("over-hydration") has no benefits and may cause dangerous hyponatremia.

Ascending slowly is the best way to avoid altitude sickness. Avoiding strenuous activity such as skiing, hiking, etc. in the first 24 hours at high altitude reduces the symptoms of AMS. Alcohol and sleeping pills are respiratory depressants, and thus slow down the acclimatization process and should be avoided. Alcohol also tends to cause dehydration and exacerbates AMS. Thus, avoiding alcohol consumption in the first 24–48 hours at a higher altitude is optimal.