What is the purpose of drinking thick water?

December 28, 2025 •

4 min read

Statistics indicate that dysphagia, a condition causing swallowing difficulties, affects a significant number of adults, particularly seniors and those with neurological conditions. The purpose of drinking thick water is to create a safer drinking experience for these individuals, reducing the risk of choking and fluid entering the lungs.

Quick Summary

Thickened water is for individuals with swallowing problems, or dysphagia. It is thickened to various consistencies to slow its flow, improving control and preventing aspiration.

Key Points

Swallowing Safety: Thickened water is primarily used to prevent choking and aspiration pneumonia in individuals with dysphagia by slowing fluid movement.
Improved Control: The increased viscosity of the liquid gives individuals more time to control the fluid bolus in their mouth and throat, ensuring a safer swallow.
Standardized Levels: Thickened water is prepared to specific, standardized thickness levels (IDDSI Levels), such as nectar or honey, based on an individual's specific needs.
Dysphagia Management: It is a core strategy for managing dysphagia caused by a range of conditions, including stroke, neurological diseases, and head/neck injuries.
Clinical Management: The use of thickened liquids must be monitored by a healthcare professional due to potential risks like dehydration and altered medication absorption.
Promotes Hydration: By providing a safer way to consume fluids, thickened water helps patients maintain proper hydration, which is essential for overall health.

The Therapeutic Role of Thickened Water

Thickened water serves a crucial therapeutic purpose for individuals experiencing dysphagia, a condition defined by difficulty or discomfort in swallowing. In a healthy swallow, a complex series of muscles and nerves work in harmony to move food and liquids safely from the mouth to the esophagus. For someone with dysphagia, this process is impaired, making thin liquids a significant aspiration risk. Aspiration occurs when food or liquid enters the airway and potentially reaches the lungs, which can lead to serious respiratory complications like aspiration pneumonia. By increasing the viscosity of the fluid, thickened water slows its movement, giving the individual more time to coordinate the swallow effectively and protect their airway.

Conditions That Necessitate Thick Water

Swallowing difficulties can arise from a range of medical issues. A speech-language pathologist (SLP) typically assesses the patient to determine if thickened liquids are necessary and what consistency is most appropriate. Common conditions that can cause oropharyngeal dysphagia include:

Neurological disorders: Such as stroke, Parkinson's disease, multiple sclerosis, and dementia.
Head and neck cancer: Radiation therapy or surgical procedures can impact the muscles involved in swallowing.
Traumatic brain injury: Can cause uncoordinated swallowing muscles.
Extubation: Patients who have recently had a breathing tube removed may need thickened liquids temporarily.
Age-related changes: Normal aging can sometimes lead to reduced swallowing coordination.

The International Dysphagia Diet Standardisation Initiative (IDDSI)

To ensure global consistency and patient safety, the IDDSI framework provides a standardized system for classifying food textures and drink thicknesses. An SLP will recommend one of the following liquid levels based on a patient's individual swallowing assessment:

Level 0 - Thin: Unmodified liquids like water or juice. Patients with aspiration risk typically avoid these.
Level 1 - Slightly Thick: Thicker than water but can still be sipped from a cup and flow easily through a straw.
Level 2 - Mildly Thick (Nectar-like): Flows slower than slightly thick liquids, similar to a cream soup or apricot nectar. A straw can be used with some effort.
Level 3 - Moderately Thick (Honey-like): Pours in a thick stream, similar to honey. It can be taken from a cup or spoon.
Level 4 - Extremely Thick (Pudding-like): Holds its shape and is not pourable. It must be eaten with a spoon.

How Thickened Liquids are Made

Thickened water is typically prepared using specific thickening agents, which are either starch-based or gum-based.

Starch-based thickeners: These are often made from modified cornstarch. They can sometimes have a grainy texture and may continue to thicken over time, which can affect consistency.
Gum-based thickeners: These, often containing xanthan gum, provide a clearer and more stable consistency over time and temperature changes.

Preparation process:

Measure the liquid (water, juice, etc.).
Add the recommended number of scoops or packets of thickener based on the desired consistency level.
Stir briskly until the thickener is fully dissolved.
Allow the liquid to stand for a specified time (often a few minutes) to reach its final viscosity.

Risks and Considerations of Thickened Liquids

While an effective tool, the use of thickened liquids is not without its drawbacks and requires careful clinical management.

Poor Hydration: Many patients dislike the altered taste and texture of thickened fluids, leading to reduced fluid intake and potential dehydration.
Altered Palatability: Thickened water can have an unpleasant mouthfeel, which can contribute to patient non-compliance.
Medication Interaction: Viscous substances can impede the dissolution and absorption of some oral medications, potentially affecting their efficacy.
Lack of Conclusive Evidence: Some studies question whether thickened liquids definitively reduce the risk of aspiration pneumonia, particularly very thick consistencies. It is crucial to engage in shared decision-making with the patient about the risks and benefits.

Comparing Thin vs. Thickened Liquids


Feature	Thin Liquids (e.g., Water)	Thickened Liquids	Target Audience
Flow Speed	Very fast; turbulent flow	Slows fluid movement	Anyone with a normal, unimpaired swallow
Swallowing Effort	Minimal effort required	Increased muscular effort needed to propel the bolus	Individuals with swallowing difficulties (dysphagia)
Control	Difficult to control in the mouth and throat	Allows more time and control for safer swallowing	Those with poor oral or pharyngeal coordination
Risk of Aspiration	Higher risk for people with dysphagia	Lower risk of fluid entering the lungs	Individuals with neurological damage or muscle weakness
Taste/Texture	Crisp, clean, familiar	Potentially altered taste and slimy or grainy texture	Patients requiring texture-modified liquids for safety
Thirst Quenching	More effective at signaling thirst satisfaction	Less effective at quenching thirst sensation	Those struggling to meet daily fluid requirements safely

Conclusion

The purpose of drinking thick water is a therapeutic strategy to manage dysphagia, a condition that impairs a person's ability to swallow thin liquids safely. By increasing the viscosity of fluids, it provides extra time and control during the swallow, mitigating the risk of aspiration and subsequent respiratory complications. While it is a widely used intervention, it is critical to address potential drawbacks like altered taste and reduced hydration with patients. The decision to use thickened liquids should always be made in consultation with a healthcare professional, such as a speech-language pathologist, who can determine the appropriate consistency and review its ongoing effectiveness.

For more clinical context on the physiological impact and management strategies for using thickened fluids, see this PMC article: Treatment burden associated with the intake of thickened fluids - PMC

Frequently Asked Questions

Thick water is used for individuals with dysphagia, a medical condition characterized by difficulty swallowing. This condition can result from various illnesses or injuries, including stroke, dementia, or head and neck cancer.

Thick water helps with swallowing by slowing the liquid's movement, providing more time for the person with dysphagia to coordinate their swallowing muscles and protect their airway. This prevents the liquid from entering the lungs.

Yes, a person without dysphagia can drink thick water, but there is no medical benefit to doing so. The taste and texture may be different and potentially unpleasant, as it is designed for a specific therapeutic purpose.

Yes, there are several standardized levels of thickness, including slightly thick, mildly thick (nectar), moderately thick (honey), and extremely thick (pudding), as outlined by the IDDSI framework.

Potential downsides include reduced fluid intake due to poor taste, leading to dehydration, and possible effects on oral medication absorption. Patient non-compliance is also a common challenge.

Thick water is made by mixing a thickening agent into regular liquid. These thickeners are available as powders or gels and can be either starch-based or gum-based.

A speech-language pathologist (SLP) is the healthcare professional who assesses a person's swallowing ability and recommends the appropriate and safest consistency level for their individual needs.

The International Dysphagia Diet Standardisation Initiative (IDDSI) recommends a simple flow test using a 10ml syringe to check the liquid's consistency and ensure it meets the required level.

While thickened fluids can reduce aspiration, some studies indicate they do not conclusively prevent aspiration pneumonia, particularly with thicker consistencies. Careful monitoring and shared decision-making are essential.