Dehydration
Dehydration can be described as an uncomfortably dry mouth and feelings of general thirstiness that results due to a lack of water intake. Untreated dehydration generally results in delirium, unconsciousness, swelling of the tongue, and (in extreme cases) death. The formal definition of dehydration is defined as an excessive loss of body water within a living organism which results in an accompanying disruption of metabolic processes.
At lower levels, substance-induced dehydration can be generally described as a sense of consistent and uncomfortable thirst which necessitates sipping at a drink to maintain fluid levels and to avoid an uncomfortably dry mouth. At extreme levels (which generally only occur through the use of deliriants), the dehydration can become so powerful that the person may find themselves with painfully dry eyes and mucous membranes in a manner which results in extreme difficulty swallowing.
Dehydration is often accompanied by other coinciding effects such as dry mouth, headaches, dizziness, decreased blood pressure, and fainting when standing up. It is most commonly induced under the influence of moderate dosages of a wide variety of compounds such as, stimulants, psychedelics, opioids, dissociatives, deliriants, cannabinoids, alcohol, and antipsychotics.It's important to note that regardless of how dehydrated a person may become under the influence of any substance, careful effort and consideration should always be put into ensuring that they do not drink water excessively as it can result in a state known as water intoxication. This can be potentially fatal and is classed as a disturbance in brain functions that results when the normal balance of electrolytes in the body is pushed outside of safe limits by over-hydration. Although extremely rare, there have been a few notable deaths which were clearly triggered by the excessive overconsumption of water under the influence of drug-induced dehydration.
The average toxic dosage of water in a human being is roughly ten litres. However, water intoxication can be easily avoided by simply being aware of it and taking care to sip at water while avoiding the consumption of unnecessarily large amounts.